Talk:Rocket/Archive 1

Archive 1

Archive 2

Suggestion for new article: space economics

I like to see information about improvements to rocket technologies. ... (Any suggestions for exactly which article ?) -- DavidCary 17:23, 11 May 2004 (UTC)

I don't mind. A space economics article might be good. There is a transport economics article. Paul Beardsell 20:24, 11 May 2004 (UTC)

I would support it. I wouldn't take the time to author it, but I would contribute to it. Rei 21:55, 11 May 2004 (UTC)

Or, we could put this information in an "economics" section of the Rocket article.

Rocketry Capital Costs

Paul, will you ever stop this? The number you're giving for what might be achievable with rockets does not repay capital costs, it has already been demonstrated, and you have never contested this. Consequently, I find it incredibly irresponsible for you to keep citing "rockets without capital costs" vs. "space elevator with capital costs". Can you not see that this is an unfair comparison? Clearly not, because you keep on doing it every other post. Rei 15:38, 20 May 2004 (UTC)

Rei, (i) a URL you yourself have given in the article itself says that a rocketry solution of $20000-40000/kg which does repay capital costs is possible; (ii) you have already said (paraphrasing) that hell will freeze over before you will consider this to be true and your POV is noted; (iii) I said "controversially" and "if"; (iv) the first para of this section is anon but not from me - was it from you? (v) you have demonstrated that the Shuttle is expensive, you said you would find out the Ariane figures - you never did so nothing is demonstrated by you about rocketry in general; (vi) I did contest your assertions, but not the ones you make about the Shuttle; (vii) I am trying to work out the economics, if you do not want to enter into the discussion in a positive way please stay away. Paul Beardsell 18:54, 20 May 2004 (UTC)

1a) Which URL are you saying? 1b) 20,000-40,000$/kg being "possible" with repayment of capital is nothing even remotely special. 2) Consider *what* to be true? Please, Paul, be more specific when you comment. 4) I wasn't responding to the first para; what I was responding to was *you* continually going off about repaying capital when either A) the shuttle is different from all other rockets in that it doesn't repay capital, or B) The shuttle is not different, and rockets don't repay their capital costs in the same way that virtually all federally funded national infrastructure programs (such as the national highway system) do not. 5) I *offered* to try and contact some people to try and get the Arianne figures, but I stated it would be a lot of work. You never responded on the subject, so I didn't. 6) If you're contesting the assertions, then lets be clear: Are you claiming option 4-A listed above? 7) I *am* entering in the discussion in a positive way in that I am doing my best to stop you from making an unfair comparison to try and unjustly smear the concept of a space elevator. Rei 19:21, 20 May 2004 (UTC)

(1a) You do not read what you cite? (1b) It is not only "not remotely special" (Rei, today); it is "impossible" (Rei, on countless former occasions) - now you have changed your position you can have no objection to me now editing the page accordingly; (2) hey, are you being deliberately difficult? that (i) is true, obviously, need I quote you? (3) there is no 3; (4) are you saying capital costs are not important? (5) so you agree that you did not demonstrate anything about rocketry in general; (6) That the shuttle was an economic disaster seems to be your point; how all the rest follows from that is difficult to see; (7) Evidently you are not. Paul Beardsell 19:32, 20 May 2004 (UTC)

1a) For God's sake, Paul, I've cited several dozen things. If you're not going to tell me what thing that I've cited that you're referring to, please stop talking about it. 1b) WHAT ON EARTH ARE YOU TALKING ABOUT? You've never told me what you're saying that I said was impossible! This is *INCREDIBLY* annoying!!! 2) No, I am *NOT*. You've been incredibly vague, and I have no idea what even the general subject you're referring to is. How am I supposed to know what "you have already said (paraphrasing) that hell will freeze over before you will consider this to be true" when you don't say what the "this" is??? 4) I'm saying, for the (insert very large number here)th time, if rockets don't repay capital costs, you can't have the elevator repay them in a comparison, or it is unfair. 5&6) What on earth are you talking about? There are two options, and I will repeat them: either A) the shuttle is different from all other rockets in that it doesn't repay capital, or B) The shuttle is not different, and rockets don't repay their capital costs in the same way that virtually all federally funded national infrastructure programs (such as the national highway system) do not. Take your pick. Rei 20:17, 20 May 2004 (UTC)

In response to your recent change of #6: They've all been economic disasters. That's what rockets are. The shuttle is a common punching bag mainly because it claimed to be able to do so much better, but turned out to be more of the same. Rei 20:17, 20 May 2004 (UTC)

1a) OK, how about looking at the very first URL cited in the Economics section of the article - the one next to the very point we have just been editing. (1b) you have been saying (and I will quote you if necessary) that capital costs cannot be recuperated out of the $20,000/kg lifted figure. (2) I am sure it is plain to other readers, and that is all I care about. (4) Here we go again! See -1b-. (5&6) See -2- but you want me to answer another "have you stopped beating my wife" question: I like neither of the alternatives you present me with. (7) Evidently your attitude remains unchanged. Paul Beardsell 20:38, 20 May 2004 (UTC)

I have placed an NPOV marker back in the Economics section. I wish to compare speculative future rocketry costs with the speculative future costs of a SE. Paul Beardsell 20:38, 20 May 2004 (UTC)

1a) Thank you. Now, given (1b) (see next sentence), how does this URL help your case? 1b) Using current rockets, you cannot recoup capital costs out of the 10,000-40,000$/kg range to LEO - correct. 2) 5&6) For God's sake, Paul, then what alternative DO you accept? I'm trying to get you to adopt a position here instead of "you're just wrong, but I'm not going to say why". How can I get you yo answer this? Hmm, lets try this - a series of questions:

A) Do you accept that the space shuttle does not repay its capital costs?

B) Do you think that rockets apart from the space shuttle - such as Ariane - do repay their capital costs?

C) If your answer to A and B are both "Yes", then: Why would you expect (B) given (A)?

I've been trying to get you to address this for a long time, and you keep refusing to. It's been ticking me off. Rei 20:51, 20 May 2004 (UTC)

The supposed logical fallacy of which you accuse me does not even need to be evaluated: Once again! I never said the words you put in my mouth: I never expected B given A. Just because a Ford is a waste of money doesn't make a Chevvy one. It is you who say this, not me: You have been criticising the whole of rocketry because the Shuttle was a lemon, using Shuttle figures. The other scattergun attacks you make at me are typical of your argumentative style, to be polite. Paul Beardsell 21:10, 20 May 2004 (UTC)

No, No, No! I'm not going to let you dodge this again. ANSWER THE QUESTIONS. If you think C is a fallacy, at least answer A and B, and I will replace C with two questions to make it clearer:

C) Why do you believe (B)? Do you have a shred of evidence to support it?

D) Why is (A) not clear evidence against (B)?

Outdent. This is a dishonest way to argue. You present me with a list of questions as if they comprehensively address the issue at hand. As if they are even the fairest questions to answer. They are asked in such a way as to somehow suggest that I have taken particular positions which I have not. (c) You are currently addressing the Ariane costs in the next section. Let's see. (d) Let's apply your argument to non-space matters: There are several Reis. One is a Wikipedian. Therefore the others are. No. You are using induction, not deduction. Paul Beardsell 21:32, 20 May 2004 (UTC)

Ariane

I think I found a way to prove that Ariane, at least currently, has not even come close to repaying its capital costs, without trying to get in touch with some people who have the raw numbers. Ariane's development capital costs were about 8 billion dollars (over 7 billion euros, not counting the recent bailout that they did) spread over 10 years. It has had 18 launches (3 of which were failures, but that's beside the point). Its payload to LEO is 16,000 kg (it usually goes to GTO, for which its payload is only 6,400 kg, but that's beside the point). That's almost 28,000$ per launch in capital costs alone. Consequently, it has not come close to repaying its capital costs at all, even if the rocket launch was free. Now I've proven that the shuttle doesn't repay its capital costs, and that the Ariane at the very least hasn't (and likely doesn't) - what more do I need to do to convince you? Rei 20:51, 20 May 2004 (UTC)

Actually, that's a good point, that I didn't even think of. We're comparing costs to LEO. The elevator goes to GEO. I'll go factor that into the article.... Rei 20:51, 20 May 2004 (UTC)

But the $25,000 Ariane figure is to either GTO or GEO not LEO. And don't forget that the next improvement to Ariane doubles the payload! Paul Beardsell 21:02, 20 May 2004 (UTC)

... and raises the launch cost. Come on, Paul, you think they're just going to rip off a piece of the rocket and say, "There we go, it carries more now!"?

Doubtless. But that doesn't mean the overall cost per kg is not decreased. Paul Beardsell 21:44, 20 May 2004 (UTC)

Ariane carries about 16,000kg to LEO and about 6,400kg to GTO. I was kind and assumed LEO in the calculations above; if you assume GTO, you over 80,000$ in capital costs per launch, making it even more ludicruous. Rei 21:18, 20 May 2004 (UTC)

I'm lost over the 80k but note the $25k is for much better than LEO, which is what you have recently tried to insert into the article itself. Paul Beardsell 21:44, 20 May 2004 (UTC)

You must quote your sources so we can see what the "development capital cost" includes. Also, Ariane's life is not over - there may be another 18 launches (=$14,000/kg "devt capital costs) or, for all I know, even a total of 72 (=$7,000/kg "devt capital costs"). How much does a rocket actually cost to build (the marginal cost of just one more rocket - i.e. without "development capital costs")? When we know that then we can divide that by the payload and add the cost of the fuel ($100 per lifted kg or thereabouts) and total that with the "devt capital costs". If(please note!) the figure is less than $25,000 we have Ariane repaying all costs if there are 72 launches. Paul Beardsell 21:02, 20 May 2004 (UTC)

You can get the development capital costs from Wikipedia, and these numbers can be confirmed in many places (for example, the FLTP article on Astronautix [1] says that its upper-end cost of 16 b$ for development is twice that of what Ariane took to develop. ). Sorry, I can't say specifically as to what is included in this, but it's clearly development costs. You never give up on this, do you? Why on earth are you so insistant that Ariane is repaying its capital cost? Name a single piece of evidence you've provided that suggests that.

I am not. Once again you are ...... ..... .... .. ..... You are insisting there is no capital repayment. The opening sentence of this section says what you are trying to do. By refusing to fairly consider the evidence, I suggest. I simply want it argued. Whenever I make a good point you boil over. Paul Beardsell 21:38, 20 May 2004 (UTC)

I mean, give me a break. Do you think the 8 billion dollars included the building of all 18 rockets launched? Do you actually believe that? Please tell me that you're not that dumb. Here's a suggestion: Before you touch the economics section again, how about youfind a shred of evidence to support your stance.'. How does that sound? Rei 21:18, 20 May 2004 (UTC)

Once again you are ...... ..... .... .. ..... I never said that. I said take the capital cost (when we know what they are), divide by the payload, add the cost of one more rocket divided by the payload, add the fuel divided by the payload, then we have the cost of one more kilogram - all costs included. I think you do not want the calculation done: I think you fear the result will contradict your prejudice. Paul Beardsell 21:38, 20 May 2004 (UTC)

Assume 72 launches, divide into $8bn. Divide by 16000kg payload to GTO or say 8000kg to GEO. $12196/kg devt capital cost per kg. Now, the additional cost of one rocket is say $100m (and that is a guess!) including fuel. That's another $12000/kg. That's a total of less than $25000/kg to GEO, capital costs included. But what is the cost of one more rocket? Paul Beardsell 22:05, 20 May 2004 (UTC)

No, I'm not going to let you get away with any of this nonsense again. I'm not going to debate someone who refuses to respond to my questions. Otherwise, I'm just speaking to a wall. 1) I demand a shred of evidence if you are to assert that claim again. I've presented several pieces of evidence that suggest that it's not true (the shuttle's lack of repayment, and the fact that the repayment schedule would have to be incredibly long). It is 2:0. I refuse to let this go on without you making it at least 2:1. Even if you personally don't like my 2, your zero is simply unacceptable.

---

mislocated

Again, I don't care if you think they're not fair. I want answers:

A) Do you accept that the space shuttle does not repay its capital costs?

B) Do you think that rockets apart from the space shuttle - such as Ariane - do repay

C) Why do you believe (B)? Do you have a shred of evidence to support it?

D) Why is (A) not clear evidence against (B)?

I never said that this "comprehensively addresses the issue at hand". These, however, ARE major problems with your argument, and you do refuse to answer them. I want answers.

I have dealt with this already. Paul Beardsell 22:28, 20 May 2004 (UTC)

Lastly, I'm sure you're not stupid. "There are several Reis. One is a Wikipedian. Therefore the others are." Oh, please. That would be reasonable if I were saying "Since the Ariane is a rocket, it should be edible." I'm not arguing over different things with the same name. I'm arguing over things that are all rockets. Rei 22:12, 20 May 2004 (UTC)

It's Logic 101. You are inferring that because the Shuttle was an economic disaster that all rockets must have the same problem. I said that was the same as saying that there are several Reis, one of them is a Wikipedian, therefore they all are. No. In both cases this is induction not deduction. Paul Beardsell 15:16, 21 May 2004 (UTC)

The shuttle is no more of an economic disaster than every other rocket! Paul, wake up and look at the launch costs!!!! They all cost a fortune, the shuttle is no different. Ariane is a disaster, too - they just had to give it a big bailout. Do you think they'd be giving it a big bailout if it was "repaying capital costs"? No, they'd just stop repaying capital costs. They all are economic disasters, because rocketry is *Hard* - something you refuse to accept. Rei 16:49, 21 May 2004 (UTC)

---

"Assume 72 launches, divide into $8bn. Divide by 16000kg payload to GTO or say 8000kg to GEO. "

Wrong. The Ariane-5 has 6,200 kg to GTO payload. If we want to call GEO half of that, that's 3,100kg. That's about 35,000$ for the 72 launches. Try again. By the way, at the current launch rate (18 launches from 1996 to 2004 - 8 years), that would take 32 years to repay.

They're not repaying. Deal. Rei 22:12, 20 May 2004 (UTC)

Depends on the cost of one Ariane V. Paul Beardsell 02:42, 21 May 2004 (UTC)

I think you do not want the calculation done: I think you fear the result will contradict your prejudice. Paul Beardsell 22:30, 20 May 2004 (UTC)

You can prove anything by assuming it first. Paul Beardsell 22:28, 20 May 2004 (UTC)

The next rockets are 12800 not 16000 kg payload, my mistake. But according to the source you quote, Wikipedia, the devt cost is $7bn, not $8bn, your mistake. We will redo the calc to find I was out by 10%. Paul Beardsell 22:28, 20 May 2004 (UTC)

At 32 years perhaps we would have it repaid before the necessary material science techniques have been developed for the SE. But if we increase the rocket launch rates some costs will be reduced. The SE needs, it seems 2,000,000 kg lifted to get to a reasonable cost / kg. That's 312 Ariane launches. Paul Beardsell 22:28, 20 May 2004 (UTC)

The "next rockets" will cost more, too - this has already been covered several times. FoWhat, do you think they're just going to rip off a piece of the side of the rocket and say, "There, done!"? For God's sake, Psb, the "it's going to carry more in the future" line of argument is just plain idiotic. It's going to carry more because they're adding the ESC-B upper stage. You think that's free?

FoWhat, you think they gonna doit at extra cost jus' for the hellovit, missy? Paul Beardsell 02:42, 21 May 2004 (UTC)

The cost is 7 billion *euros*. A euro is worth more than a dollar. YOUR mistake.

OK but maybe: The euro did not even exist when the Ariane was developed. What with currency movements in the interim it is difficult to determine the USD costs. But, what the heck, so I am 20% out. As I said, the $100million was a guess. You're the one with the access to hidden facts: How much is one Ariane V?

At 32 years, you would be repaying it if we charged 35,000$ per kilogram more than the base geosync cost. Please, go on, tell me that Ariane costs a lot of negative money to get into geosync. Rei 22:53, 20 May 2004 (UTC)

I can recognise the unmistakable sneer in your post but that's as far as I get. Paul Beardsell 02:42, 21 May 2004 (UTC)

Oh, hey, speaking of the ESC-B: it's on hold indefinitely. [2]. Rei 22:59, 20 May 2004 (UTC)

This is all just diversionary tactics away from the main argument. You just don't want the comparison done. And I do not know if it repays all the capital devt cost or not. But I would like to know from the facts rather than just take it on your say so. Paul Beardsell 02:42, 21 May 2004 (UTC)

Ok, lets just let it be known officially: Paul has refused to answer my questions. He has refused to back up his assertion, which he keeps on making. Consequently, Paul is refusing to discuss. Consequently, he should not be allowed to edit in this dispute. I'll repeat them, in case you ever feel like rejoining the discussion, Paul:

A) Do you accept that the space shuttle does not repay its capital costs?

B) Do you think that rockets apart from the space shuttle - such as Ariane - do repay

C) Why do you believe (B)? Do you have a shred of evidence to support it?

D) Why is (A) not clear evidence against (B)?

I'll add one more:

E) If Ariane was repaying its launch costs, why would it have had to have a major bailout recently? Wouldn't they just stop repaying capital costs?

lastly, as mentioned earlier....

1) I demand a shred of evidence if you are to assert that claim again. I've presented several pieces of evidence that suggest that it's not true (the shuttle's lack of repayment, and the fact that the repayment schedule would have to be incredibly long). It is 2:0. I refuse to let this go on without you making it at least 2:1. Even if you personally don't like my 2, your zero is simply unacceptable.

P.S.: "Preparatory work began in 1984. Full scale development began in 1988 and cost $ 8 billion." [3]

P.P.S.: The page has changed since then, but look at this google cache: [4]. Notice at the bottom: "... of the Ariane 5 contracting team have agreed to reduce their costs to permit Arianespace to assemble, fuel and launch an Ariane 5 rocket for 136 million euros." Drive another stake in your mistaken notion. NO CAPITAL COSTS. "Assemble, Fuel, and Launch". Rei 16:49, 21 May 2004 (UTC)

Rei continues to say I have said things I have not. She is repetitively and dishonestly doing so. Paul Beardsell 17:51, 21 May 2004 (UTC)

moving stuff from Talk:Space elevator

This stuff seemed more relevant at Talk:Rocket than Talk:Space elevator. I hope you can use it on the main Rocket article. -- DavidCary 10:19, 27 May 2004 (UTC)

Propellant for "Fuel"

In the Art, the term "fuel" is exclusively used for the energetic or combustible component of the rocket propellant combination as contrasted to the "oxidizer". The combination of both (in a bi-propellant system) is termed "Propellant". In the case of a single substance it is termed "Monopropellant". In hetero or homogenous solid compositions they are termed "Solid Propellants". The article will be improved thereby by substituting "Propellant" for every instance of "Fuel".

BC

Done. -- DavidCary 15:12, 13 May 2004 (UTC)

---

"A rocket is any device that propels itself using reaction mass; see Newton's 3rd Law of Motion".

Actually the complete sentence currently reads: "A rocket is a vehicle, missile or aircraft which obtains thrust by the reaction to the ejection of a fast moving exhaust from within a rocket engine."

Now, I can understand if that sounds a bit circular; but it really isn't.

I don't feel this definition is at all accurate. It applies also to jet engines

Conventional jet engines and rocket engines involve combustion and jets of hot gas from nozzles, but rocket engines very definitely do have big differences from jet engines- jets have air inlets, rockets don't; the exhaust speed from a jet engine is almost an order of magnitude lower than from a rocket engine; the chemistry of the exhaust if vastly different- rocket engines run extremely fuel rich as this increases the exhaust velocity; jet engines run 'air rich' as this keeps the exhaust velocity as low as possible.

with a high thrust

and even a catapult

Not really possessing a rocket engine though. There's no nozzle.

- such a device could be used to propel a vehicle by throwing a rock backwards.

Yup. Does it have a rocket engine though?

A proper succint definition is quite elusive; the OED and Macmillan Encyclopedia for example have quite long-winded definitions, so they've run into the same problem. Macmillan states: "vehicle or missiles powered by jet propulsion that carry their own fuel and oxidiser...". OED has "engine containing its own propellant and depending for its operation on reaction due to continuous jet of rapidly expanding gases released in combustion of propellant". The key points are that a) the rocket carries all of its propellant including the oxidiser, and b) the reaction mass results from the combustion of this fuel. I will have a go at rewording the definition, though if anyone can think of a better one, feel free to give it a go. GRAHAMUK 03:04, 6 Dec 2003 (UTC)

I don't feel that Macmillan captures it. I don't agree that hot gas or combustion is necessarily significant (see water rockets or steam rockets). IMO but there's probably the following properties that characterise a rocket engine:

a) propellent is carried onboard the vehicle

b) exhaust consists of a fluid

c) exhaust is emitted through a nozzle that increases the speed of the fluid

Of course there's nothing cast in stone about this list; if you tried hard enough you can doubtless come up with your own different definition.

Note that ALL of these are necessary for an engine to be considered a rocket. Jet's have nozzles but are not rockets. Catapults could theoretically be classed as a rocket engine, but I don't feel it quite qualifies, it's just a reaction drive. Scramjets have fluid exhaust, but aren't rockets, they are jets, since they use the air as part of the propellent.

If "combustion" becomes part of the definition of a rocket, then things like "ion thrusters" and "Nuclear thermal rockets" are technically not rockets. That's OK -- we could just call them "thrusters" or something.

I don't see that combustion is necessary- look at water rockets. Fluid exhaust seems to me to be. Nuclear thermal is definitely a rocket in my book. Even VASIMR, since it has the hot fluid and a nozzle, and uses onboard propellent. Ion drives are pushing it, there's not really a nozzle, and it's not really a fluid, it's a plasma; but that one's very borderline.

terminology question: what would you call other things in this tree?:

• devices that propel themselves using a reaction mass, which includes

 * jet engines and other things that burn oxygen from the air

Jet, since it sucks in the air and uses it as part of the propellent

 * squid (I think people have been calling that "jet" of water long before aircraft were built).

well, it sucks in the water before expelling it, so it has an inlet. I think you could argue that one either way, since once it has sucked it in, it works like a water rocket. I mean all rockets get filled at some point :-) On balance I'd say jet, since the inlet equipment is carried around with the vehicle, I mean creature.

 * devices that carry all their propellant with them
   * ice skater shooting machine gun backwards

There's no nozzle in the conventional sense, and solid exhaust; although the powder burn will provide some recoil and would count. Arguable; but I'd say not; the nozzle is not intended to increase the velocity of the burnt powder.

   * ion thrusters

No nozzle.

   * Nuclear thermal rockets

Yup. Nozzle. Fluid exhaust. No air inlet. Rocket.

   * devices that burn fuel to produce the reaction mass

If they have a nozzle, and don't suck in air, they're a rocket.

-- DavidCary 04:53, 12 May 2004 (UTC)

So, my 3 rules seem to work. There's clearly other rules that can apply and they may end up classifying differently- but my rules seem to be simple, and work well enough (unless anyone can come up with a clear counterexample). --Wolfkeeper 16:06, 30 May 2004 (UTC)

Prices

Wolfkeeper has brought up a couple new systems that haven't been discussed yet.

Soyuz: Let's pick on in the series at random - say, Soyuz FG. Launch cost 50m$, payload 7420 to 51.8 degree inclination. Price in 1994 dollars=50m$, Prince in 2004 dollars~=70m$. Just under 10k$/kg.

"Chinese": assumedly he means "Long March": Lets pick a random one; the CZ-4A. What do we find? 30 million dollars in 1994 -> ~45 million now, 4,680kg payload... just under 10k$/kg again.

Ones he mentioned that were already discussed:

"Sea Launch" - Assumedly he means the never built Sea Dragon, whose design proved to be not only overly optimistic, but an outright failure, when a smaller version was built as SEALAR. Or he could mean a number of other things...

No I mean sealaunch. Hey, here's an idea, why don't you use google? You know- research? I even included a reference to a data source that gave it's launch costs... (If your google is broken (funny how Rei's google is always broken when it comes to cheap conventional rocketry), Sea Launch is a Boeing/Russian joint effort- with *seriously* cheap rockets...) Wolfkeeper

Sorry, we were discussing the Sea Dragon earlier here, which was a never-built rocket that Truax claimed could get spectacular returns. "Sea Launch" is often used as a generic term; you should have stated Zenit-3SL with a Block DM-SL to get to GEO, instead of citing the company - "Sea Launch" is not a rocket. Lets look at the geostationary transfer orbit so we don't have to factor the Block in... the Zenit-3SL itself costs over 100m$ in current dollars (90m$ in 1999), and has 5,250kg payload. That's almost 20,000$/kg to geosync transfer [5]. Even if you assume that you can get twice as much to LEO, that's still not cheap. Rei 20:48, 25 May 2004 (UTC)

I did cite Zenit-3SL you removed that from the article! It's not my fault if you don't known what launch vehicle Sea Launch use! Actually, a LOX/Kero stage like the third stage of Zenit-3SL the appropriate multiplier is 3x, giving a price to LEO of ~$6600/kg, even with your more pessimistic figures. Most other vehicles use hydrogen which is more efficent, and then 2.5x is more like it.--Wolfkeeper 00:39, 27 May 2004 (UTC)

I didn't remove a thing from the article - check the history. I don't like the accusations, either. Care to back up your LEO claim? Rei 16:13, 27 May 2004 (UTC)

Sure, no problem. Go to [6] where it lists the delta v to go from LEO to GEO as 3800m/s. Then take the rocket equation: deltaV = exhaustVelocity * ln(InitialMass/finalMass). Exhaust velocity for LOX/Kero is about 3500m/s in space situations. Solve the equation and you get an initialMass/finalMass ratio of 3. i.e. 2/3 of your mass to LEO is fuel used to get to GEO. The rest is payload and rocket engines and so forth. Unlike launch situations, zero-g rocket engines provide very low thrust and are usually exceedingly low mass; so to a first approximation (within a few percent) can be neglected. Feel free to compare this with actual launch vehicles figures. In some ways this calculation is pessimisic- it assumes you go to LEO, and then go to GEO; it's more efficient to launch straight into GTO and add a circularising burn into GEO. Also, if you are going to LEO you may need one less stage which reduces costs further. Wolfkeeper--81.174.170.32 17:34, 30 May 2004 (UTC)

Wolf, if you'd read the talk page (I know, it's monstrous, and has lots of fighting!), you'd be familiar with the fact that launch costs have remained relatively stagnant since the 1960s,

They were cheaper in the 60s due to high production rate of icbms. They are cheaper now because the encumbents are actually having to reduce costs- there hasn't been that pressure before.Wolfkeeper

Once again, more uninformed speculation. Care to provide a reference, Mr. References? Rei 16:13, 27 May 2004 (UTC)

Most rockets were not based on ICBMs. Rei 20:48, 25 May 2004 (UTC)

Wrongo. In the 60s most *were* based on ICBMs

Well, lets see... what were the workhorse rockets of the US back in the 60s? Off hand, I'd say the Titan and Saturn series. The Titan used in the space agency was based on an ICBM for the lower two stages, with non-ICBM upper stages added (such as the Titan Transstage, the Agena D, the Centaur D/E, etc). The Saturn series was unrelated to ICBMs for all of its stages. That's one which has some ICBM stages (but not others), and one completely unrelated.

Precisely my point. The Saturn was 2 or more times more expensive, because it didn't have the economies of scale of ICBMs.

This is "most"?

Yeah. Definitely most of the cheap ones anyway; I can't be bothered to count them by launches, but I expect ICBMs launches were certainly more numerous. Don't forget Mercury used Atlas.

Oh, I forgot, we need the Atlas series also. It works out the same as the Titan (ICBM lower stages, non-ICBM upper stages. Rei 16:13, 27 May 2004 (UTC)

Yup. Atlas was fairly cheap too. p.s. Mercury used Atlas for launching; quite a few Mercury launches.

and that while NASA is working on reducing costs to 25% of their current level, it's been a slow program that is way behind schedule. Rei 00:09, 25 May 2004 (UTC)

I wasn't aware that there was a schedule. The main reason that the price is flat is due to perceived price inelasticity in the market. The encumbents can reduce prices, but if they do they make less money (noteably the Ruskies; Ariane and the American launchers are only partly commercial and use cost-plus contracts and other political perversions- and yeah Ariane nearly went bankrupt a while back and got bailed out which makes it even more complicated to work out what went on.) Wolfkeeper

Laf, you don't think SLI has a schedule? Amusing.  :)

No, they have a schedule. And they had one last year, and the year before. None of them are remotely the same.--Wolfkeeper 00:39, 27 May 2004 (UTC)

Please explain how, with a 500-600m$ launch cost, the shuttle is repaying its capital costs.

You're so last year. They've just got an accountant as their head honcho- and he's insisted that their accounts make sense. The price per Shuttle launch is now officially nearer $2 billion!!!!--Wolfkeeper 00:39, 27 May 2004 (UTC)

NASA, before the shuttle disaster, has been averaging 5-6 shuttle launches per year [7].

See: [8] "_$15.2 billion over the next decade or so to add a fifth shuttle flight to the annual schedule. The shuttle has been limited by budget constraints to four flights a year and nearly all have been dedicated to assembly of the space station. The added flight could be used to accelerate station assembly or to perform other missions that are not now possible." That's 1.5 billion per flight, per year.

The shuttle's budget is usually around 3 billion dollars [9].

That depends on precisely what parts of NASA you ascribe to the Shuttle. If you quite reasonably count some of the other bits of NASA my understanding is that it is nearer 6 billion dollars per year; and the latest accountancy figures reputedly suggest that to be the case.

Get a grip on yourself

Alright; call it 1.5 billion per flight.

- 2 billion dollars a launch would be almost NASA's entire budget.

Actually NASAs yearly budget is more like 15 billion, and they don't usually launch 6 times a year. Check out: http://groups.google.com/groups?q=constant+dollars+budget+nasa&hl=en&lr=&ie=UTF-8&as_drrb=b&as_mind=12&as_minm=5&as_miny=2000&as_maxd=30&as_maxm=5&as_maxy=2004&selm=9ad41526.0307161413.6820d53c%40posting.google.com&rnum=2

Why do you keep making claims on things you know nothing about?

I don't :-) p.s. I don't know why you're complaining, you're the one always trying to make launchers expensive. :-)

Rei 16:13, 27 May 2004 (UTC)

Please explain how, given the cited cost to build, fuel, and launch an Ariane rocket, they're repaying capital costs. Also, when you do such a comparison, try and determine the amount of time it would take to pay back the system. For example, if Ariane makes 2,000$ per kilogram to geostationary transfer, then, in the 18 launches in 6 years (ignoring the fact that 3 of them were failures), they would have only repaid 200 million of their 8 billion dollar cost. Rei 20:48, 25 May 2004 (UTC)

Arianespace went bankrupt and got bailed out. Big deal.--Wolfkeeper 00:39, 27 May 2004 (UTC)

---

NASA is working to reduce costs to 1/4 of what? I want to put the figure in: I saw a figure somewhere that NASA's target was $1500/kg. That target may have now been abandoned but presumably they must have once thought this realistic - I mean: It was a target stated as policy. The SE is not a stated policy target yet the article takes the SE very seriously, I think it should take a stated policy target from NASA also very seriously. It is the aim of the Economics section to compare the speculative SE with the speculative costs of future rocketry, is it not? Paul Beardsell 20:31, 26 May 2004 (UTC)

I had a page on NASA that discussed it in more detail before, but I can't locate it any more. Looking for it, though, I ran into an Aviation Now article discussing how SLI funding has been partially shifted to building a lifeboat for the ISS [10].I really wish NASA would get more information on their SLI website and clean it up; it's a big collection of dead-links and scattered pages.

Hmm... this isn't encouraging: [11]. I never heard about this, but an earlier NASA study determined "The basic structure of the SLI (program orientation, objectives, schedule, technology) renders the program impossible for successful completion. The elements are so obviously lacking in credibility as to discourage best efforts by either government or industry." Rei 21:11, 26 May 2004 (UTC)

Just thought I'd say that what I see as the main problem for most spacecraft (including NASA itself) is that none of the are future proof (yes it is an american military term) and therefore can't adapt to new, cheaper technolgy very quickily. For example if were to make the shuttle's inside into modules (like a few of the massive US subramines) and make components removable not only would you have a more flexable shuttle (allowing for more missions) but you wouldn't have to wait ages (and pay alot of money) before new components are installed (e.g. some one comes up with a better heat shield). (sorry if this doesn't make that much sense but take a look at what the US is developing for a better idea)

Goddard's First Liquid Fuel Rockets?

A team of amateur rocket engineers had formed the Verein für Raumschiffahrt (German Rocket Society, or VfR) in 1927,

and in 1931 launched a liquid propellant rocket (using oxygen and gasoline).

This makes it sound like Germans launched the first liquid-fuel rocket, while usually Goddard is credited with this feat (in 1926), but not in this article.

Can somebody shed more light...? -- Syzygy 07:57, 12 April 2006 (UTC)

Patents of interest - move

I am moving the "Patents of interest" section in Goddard's article as they are more relevant to him than to the history of rocketry in general. -- Goldie (tell me) 20:24, 12 April 2006 (UTC)

Fold in FFAR page?

Kind folks, I found the entry for Fin-folding aerial rocket, which appears to be erroneous on its face. Notably, Folding-fin aerial rocket redirects here. I think the Fin-Folding page probably ought to be deleted, but there may be some worthwhile information in there that could be used here or on related pages. Volunteers? --Thatnewguy 13:45, 5 July 2006 (UTC)

Beginnings of rocketry

Where did the "B.C. 300" (sic) date come from? Brunnock 11:28, Apr 16, 2005 (UTC)

See http://www.bafsat.com/h4.html. Looks like gunpowder is 300 B.C. anyway. We know that the chinese invented rocketry between 300 BC and 1232 AD when there is evidence of their use in battle. Wolfkeeper 14:09, 2005 Apr 16 (UTC)

The gunpowder article states that it was invented in the 9th Century. Brunnock 15:30, Apr 16, 2005 (UTC)

That's only a stub though. Wolfkeeper 17:08, 2005 Apr 16 (UTC)

The black powder article states that it was invented in the 9th century. Brunnock 17:48, Apr 16, 2005 (UTC)

Check out: http://www.spacetoday.org/China/ChinaHistory.html

"Sometime between 300 B.C. and A.D. 1000, "fire arrows" were used in China, but historians aren't sure if those were rockets or merely conventional arrows burning." Wolfkeeper 23:49, 2005 Apr 16 (UTC)

http://www.life.com/Life/millennium/events/07.html

http://concise.britannica.com/ebc/article?tocId=9366334

http://www.bartleby.com/65/gu/gunpowde.html

http://www.cambridge.org/uk/catalogue/catalogue.asp?isbn=0521303583

http://afe.easia.columbia.edu/song/readings/inventions_ques.htm

http://www.fieldmuseum.org/forbiddencity/trivia.html

http://www.amazon.com/exec/obidos/tg/detail/-/0465037186/104-0815507-8936731?v=glance

http://www.dummies.com/WileyCDA/DummiesArticle/id-1225.html

Wolfkeeper, the 8 references above all state that gunpowder was invented in China in the 9th century. Why does this article state that the Chinese invented gunpowder much earlier? --Sean Brunnock 00:47, 12 September 2006 (UTC)

The fire arrows are rockets. They have what is supposed to be the "engine", or the pouch of gunpowder tied to an arrow. Koreans also made their own version of the fire arrow called Shinkichon, and its range varies around (large size) 2km ~ (medium) 1km ~ (small) 200m, etc. Therefore, the Mongolians are not the first ones to build rockets. (Wikimachine 02:46, 18 May 2006 (UTC))

First rockets

I'm wondering whether the aeolipile counts as rocketry. Certainly the arms are pushed around by rocket effect from the steam exhaust, and the tips are actually nozzles. Thing is, it predates the chines by about 1000 years... It's not free moving though; and I guess this article is about rocket vehicles; even if it doesn't say that.WolfKeeper 05:43, 24 January 2006 (UTC)

No, they're not rockets.

Yes they, are. The device contains two rocket engines- it uses jets for propulsive purposes using propellant that is stored within it until use.

I can easily cite that the arms are pushed around by jet effect, and the kind of jet is very clearly a rocket jet. That this is a rocket engine is not in any way contentious. And 'rocket' is simply another name for rocket engine; they're used interchangeably.WolfKeeper 17:36, 11 September 2006 (UTC)

In what sense are they *not* rockets? An internally stored working fluid is expelled through a nozzle, generating thrust. What more is required? Evand 03:54, 12 September 2006 (UTC)

A citation. See WP:CITE. All references that I have found state that rockets were invented in China. Wolfkeeper claims they were invented in Greece. That's original research. --Sean Brunnock 11:26, 12 September 2006 (UTC)

All that's being stated is that the aeolipile meets the definition of a rocket. Application of a definition does not seem to me to be original research. Evand 17:58, 12 September 2006 (UTC)

They spin around and provide rotational energy.

Yes.WolfKeeper 17:36, 11 September 2006 (UTC)

I notice that you edited this article, Aeolipile, and Timeline of invention stating that the aeolipile is the first rocket or a "static rocket".

That's because it is. :-) WolfKeeper 17:36, 11 September 2006 (UTC)

This is original research. Please stop.

I don't really see how it can be OR if I'm just picking words to describe it out of the dictionary, and I'm not using any of the words in non standard ways.WolfKeeper 17:40, 11 September 2006 (UTC)

According to NASA [12] and the Columbia Encyclopedia [13], rockets were invented in China. --Sean Brunnock 16:53, 11 September 2006 (UTC)

It does depend what they mean by rocket- a rocket can be another name for rocket engine, or a name for a vehicle or missile containing rocket engines; clearly they're refering to the latter usage.WolfKeeper 17:36, 11 September 2006 (UTC)

Please read these articles - WP:CITE (cite sources) and WP:OR (no original research). These are core Wikipedia policies. Go to Google and look up "static rocket" and aeliopile. The only page that matches those terms is this rocket article. Please stop referring to aeliopiles as "static rockets" and please stop doing original research. If you want to prove your point, then please cite something. --Sean Brunnock 17:44, 11 September 2006 (UTC)

I certainly will add citations to the aeolopile article. It's a bit of a waste of my time, and I'm surprised you're making me do this, but still CITE is CITE. Given I can easily cite, OR is irrelevant in this case.WolfKeeper 18:05, 11 September 2006 (UTC)

The reference you just cited states, The date reporting the first use of true rockets was in 1232. [14] It doesn't refer to the steam bird as a rocket. It appears that you're misquoting. --Sean Brunnock 00:25, 12 September 2006 (UTC)

Since they have not defined a 'true rocket' (tm) anywhere, then I am not.WolfKeeper 02:13, 12 September 2006 (UTC)

I'm sorry to read that you have no idea what a true rocket is. Allow me to enlighten you-

The first reaction engine, the aeolipile (a ball that rotated as a reaction to escaping steam),
was constructed by the inventor Heron (or Hero) of Alexandria. Developments through the centuries
have resulted in two general types of reaction machines, the true rocket and the airstream engine,
commonly known as the jet engine. Unlike a jet engine, a rocket engine carries with it chemicals
that enable it to burn its fuel without drawing air from an outside source.
- The Columbia Electronic Encyclopedia, Sixth Edition Copyright © 2003, Columbia University Press

--Sean Brunnock 11:59, 12 September 2006 (UTC)

Except that it is very clearly stated everywhere that the aeolipile contains its propellant internally, and does not use air for reaction mass. That makes it a (steam) rocket, not a jet. Evand 17:51, 12 September 2006 (UTC)

The fire which heats the water is external and the fire gets its oxygen from the air. It's not a rocket. No one calls it a rocket. If you want to cite something which states that it's a rocket, then great. Otherwise, stop playing games. --Sean Brunnock 20:46, 12 September 2006 (UTC)

That just makes it a thermal rocket, as in solar thermal rocket or nuclear thermal rocket. It doesn't make it not a rocket. Rockets are defined by the exhaust jet, and the source of the propellant, not the mechanism used to generate the heat.WolfKeeper 21:19, 12 September 2006 (UTC)

I'm not playing games, and I resent the assertion. I'm not trolling; I think the aeolipile fits any reasonable, modern definition of a rocket (excepting the military definition as an unguided tactical missile). The propellant, as distinct from the energy source, is internally contained and constitutes the entire reaction mass. All steam rockets (that I know of) draw their energy from an external source. There are plenty of other things that are unambiguously rockets that have an external power source. Solar thermal rockets, ion engines, and resistojets all come to mind (the last two could be powered by an onboard source, but are more normally powered by solar panels). The fact that the nozzles are oriented to generate rotational rather than linear force is also irrelevant -- many guided rockets have roll control thrusters, which are just small rockets. Combustion of the propellant is also not required -- see again solar thermal rockets and ion engines, and add cold gas thrusters, nuclear thermal rockets, water rockets, and, depending on your definition of combustion, hydrazine and peroxide monopropellant rockets. Also, I don't think the CEE you cited above is in disagreement with the statement that the aeolipile is a rocket -- it classes it as a reaction engine, and then divides reaction engines into rockets and jets, without specifying which if either the aeolipile is. I honestly don't know how to define a rocket in such a way as to exclude the aeolipile and still include all the things that are normally considered rockets, without specifying "and not an aeolipile". Evand 21:37, 12 September 2006 (UTC)

You're doing original research. If you can't cite something that says that an aeolipile is a rocket, then you can't call it a rocket (in a Wikipedia article). You want to write and publish an article which states that the Greeks and not the Chinese invented rockets, then be my guest. Otherwise, stop rewriting the history articles. --Sean Brunnock 22:24, 12 September 2006 (UTC)

Please stop accusing me of things I didn't do. I have not rewritten any of these articles, I have limited my opinion to the talk pages. Evand 00:29, 13 September 2006 (UTC)

I've got zillions of articles that say that it is 'rocket-like', lots that say it is a reaction engine, and many, many that say it is a form of a jet engine (a rocket engine is a form of jet engine), but nobody really ever states what sort of jet engine. Henry Spencer says that it is probably a form of 'rocket turbine', but doesn't have a definition of what a rocket turbine is; and there's the added problem that being a rocket turbine doesn't actually preclude it from being a rocket, or containing a rocket engine. I've also found examples where rockets propel things around in circles, giving no direct lift from the rocket, and everyone agrees that those are rocket engines. Basically, everyone skirts the issue. To describe it as a rocket is consistent with all of these references; and also with the actual definition of rocket engine itself. But I assumed you wouldn't be happy with any of this; but then perhaps I am assuming bad faith.WolfKeeper 23:08, 12 September 2006 (UTC)

Everyone says it's "rocket-like" because it's not a true rocket. The Columbia Encyclopedia makes the distinction. Why can't you? --Sean Brunnock 23:24, 12 September 2006 (UTC)

Because everyone who talks about aeolipiles seems to be using a definition of a rocket distinct from the one Wikipedia uses. I believe it is wrong to have inconsistent statements presented as fact on Wikipedia. Since in this case the only thing required to rectify the different statements is consistency in definitions, it seems entirely reasonable to apply the Wikipedia definition consistently, even when no external citation is available. IMHO, the reason for this is that few people who study aeolipiles concern themselves with using a strict, modern definition of a rocket, and few rocket scientists concern themselves with the details of exactly when and where rockets were invented. The only disagreement is a result of differences in definitions, and all references that say the aeolipile is "rocket-like" appear to be using a different definition than Wikipedia. Also, I do not see any references which explicitly state the aeolipile is not a rocket. Evand 00:29, 13 September 2006 (UTC)

Hold the phone. What do you mean by "Wikipedia definition"? --Sean Brunnock 00:32, 13 September 2006 (UTC)

Basically, I mean the criteria WP articles seem to use in describing machines as rockets / not rockets. I mean any of several definitions; it doesn't matter which. For starters, I mean a rocket engine, without specifying a specific application or vehicle. I don't mean the traditional military definition of an unguided rocket-engine-propelled missile. I'm quite happy with a proposed definition at the top of this talk page as something that has a (substantially) fluid exhaust expelled through a nozzle, with the propellant stored internally. Alternately, I mean any definition which includes those things WP includes as rockets, without including excessive numbers of other things. At a minimum, this should include bipropellant, hybrid, and solid motors, steam rockets, thermal rockets (solar, nuclear, laser, and microwave), cold gas thrusters, monopropellant thrusters, resistojets, electric arc jet thrusters, ion engines in all their various forms, and water rockets. Evand 00:46, 13 September 2006 (UTC)

I'd be appreciative if you'd make an effort to be more succinct. You're telling me that you guys came up with your own definition for a rocket? --Sean Brunnock 00:48, 13 September 2006 (UTC)

OK, I'll try to be succinct. I was avoiding being succinct in order to avoid coming up with my own definition. My personal definition is anything which generates a reaction force by expelling a basically fluid reaction mass through a nozzle in order to generate a reaction thrust, with said fluid coming from an internal source. Unfortunately, WP does not appear to have a definition anywhere that is consistently applied. However, I believe that the definition in de facto use is the one I just gave (or something substantially similar). And it's not "our" definition in any sense at all. I would appreciate it if you would pay attention to WP:good_faith and act as though we were trying to improve the consistency and accuracy of Wikipedia, not impose a personal opinion. Evand 01:01, 13 September 2006 (UTC)

Your opinion doesn't matter. It's what you can cite that matters. I think it's pretty clear that you and Wolfkeeper are engaging in original research. Stop rewriting Wikipedia articles to reflect your opinion. --Sean Brunnock 01:09, 13 September 2006 (UTC)

I am not rewriting Wikipedia articles. Please retract that statement. Evand 02:48, 13 September 2006 (UTC)

It doesn't even matter what Columbia Encyclopedia, and what some random websites think about aeropiles. The general consensus around the world is that China invented the first rocket, and it will stay that way. (Wikimachine 22:42, 21 October 2006 (UTC))

Steam rockets or no, I think this section is poorly written and rushed. Can we get some names of early Chinese rockets? Who developed them, and where? I'm pretty sure the information is out there. What were their early uses? What did they look like? The part about the transmission of rocket technology across the globe and to Europe is particularly messy. It sounds like the writer is correcting themselves as they type. The description of the Mongol conquest of China is a little clumsy and almost vindictive, as if the writer were from Norther China and were bitter about the invasion. I'm sure this wasn't the intention but please fix the writing style a bit. Thanks. -Casual Reader, 21:20, 28 March 2007

Definition discussion

I apologize for the USA-centric references in the initial article. Please list significant USSR/Russian developments where appropriate. -- ansible

Removed reference to nuclear rockets being against treat_{^{Subscript text}}y. Nuclear pulse rockets would have problems, but there is no treaty to prevent the use of nuclear thermal ones.

Edit "The origin of rockets as most people think of them dates back over 1,000 years ago when people of the Han Dynasty in China (c. 206 BC – 220 AD) began experimenting with gunpowder and fireworks" 206 BCE would be 2,000 years ago, not "1,000 years" ago. Changed this. -intranetusa

"According to the writings of the Roman Aulus Gellius the first rocket engine seems to have been c. 400 BC when a greek pythagorean philosopher named Archytas of Tarentum propelled a wooden bird along wires using steam. " I deleted this part because a steam powered device is not a rocket engine.

Says who? You do know about steam powered rocket cars? And are you seriously claiming that it doesn't meet the definition of rocket engine? Exactly which part of the definition in rocket engine does it fail to meet? WolfKeeper 02:49, 20 October 2006 (UTC)

You're supposed to quote a reliable source, not an article that you edited. The American Heritage Dictionary, for example, defines a rocket engine as a reaction engine that contains all the substances necessary for its operation and is not dependent on substances such as atmospheric oxygen, drawn from the surrounding medium, and thus is capable of operating in outer space. [15] --Sean Brunnock 11:26, 20 October 2006 (UTC)

Oh please, not that definition again. You're not seriously saying you think that's a good definition of a rocket engine, are you? Dictionaries are an excellent source of a layman's definition, but not for a term of art, be it rocket science or international law. How about we use a definition from a more relevant source? Sutton, 7th ed, pg 1: "Rocket propulsion is a class of jet propulsion that produces thrust by ejecting stored matter, called the propellant." Later on the same page: "Other energy sources, both internal (in the vehicle) and external, can be considered." Those definitions aren't precise, but at least they avoid the problem of the AHD of excluding things that are clearly rocket engines and including things that clearly aren't. Evand 18:57, 21 October 2006 (UTC)

How about NASA's Aerospace Science and Technology Dictionary? Rocket Engine- A reaction engine that contains within itself, or carries along with itself, all the substances necessary for its operation or for the consumption or combustion of its fuel, not requiring intake of any outside substance and hence capable of operation in outer space. See [16]. --Sean Brunnock 21:26, 21 October 2006 (UTC)

It's important that a definition define something correctly in all cases. I personally don't consider mass drivers to be rocket engines; but they are reaction drives. That definition says that they are rocket engines. I therefore respectfully disagree with that definition. Sutton is generally recognised as a more authoritive source on rocketry matters I think, and their definition precludes mass drivers.WolfKeeper 22:06, 21 October 2006 (UTC)

Also, operation in space is not a normal part of the criteria. There are plenty of engines that won't operate in space. For example, the SSME can't ignite in a vacuum, or in free fall. XCOR's tea cart engine can ignite in vacuum, but wouldn't operate if chucked out the air lock, if only because it uses batteries that wouldn't survive the process. And depending on how you read it, the NASA definition would preclude solar and microwave thermal thrusters, along with any externally powered ion drive or resistojet. The only criteria I can see that don't produce some really bizarre results are 1) internally stored propellant and 2) thrust solely produced by expulsion of that propellant through a nozzle in an effectively fluid form (liquid, gas, or plasma, potentially with solid particles). Evand 22:26, 21 October 2006 (UTC)

I hate to break it to you, Evan, but the Rocket engine articles states, A rocket engine is a reaction engine that can be used for spacecraft propulsion....

...as well as terrestrial uses. Troll.WolfKeeper 00:07, 22 October 2006 (UTC)

Neither of you has cited anything that supports your position that the Greeks invented rockets. --Sean Brunnock 22:57, 21 October 2006 (UTC)

(Shrugs.) Since when does putting a rocket on a bearing make it not a rocket? That's all an aeolipile is.WolfKeeper 23:03, 21 October 2006 (UTC)

You're doing original research. --Sean Brunnock 23:51, 21 October 2006 (UTC)

More trolling.WolfKeeper 00:07, 22 October 2006 (UTC)

Please read the 2 definitions that I cited above. --Sean Brunnock 23:51, 21 October 2006 (UTC)

Maybe later. I haven't stopped laughing at you from the first time I read them yet.WolfKeeper 00:07, 22 October 2006 (UTC)

Both of those are awful as technical definitions. They include mass drivers as rockets, which is far more questionable than including the aeolipile. Furthermore, they exclude rockets that use an external energy source such as most ion drives (which operate with energy from solar panels). They also exclude a *huge* collection of rocket engines that can't operate in vacuum without modification of one or more components (usually either ignition system or control electronics -- many electronics require air cooling). While they do a fine job of informing a layman, they don't even begin to draw appropriate boundaries from a technical standpoint. Have you considered leaving the rocket science to the rocket scientists yet? In case you weren't aware, both Wolfkeeper and I are professional rocket engineers. Evand 00:48, 22 October 2006 (UTC)

NASA's definition isn't good enough? Who's definition are you using? --Sean Brunnock 00:59, 22 October 2006 (UTC)

Sutton's. The NASA definition is a layman's definition, not a technical one. Sutton's Rocket Propulsion Elements is a classic introduction to applied rocket science. There is a copy sitting on just about any rocket engineer's book shelf. Furthermore, the definition has the merit of actually defining the device in question in a fashion that excludes things like mass drivers and galley slaves chucking bowling balls out of spaceship airlocks (which both your definitions would call rockets), and not excluding things like solar thermal rockets and most solid propellant rockets ever built (which won't ignite in a vacuum, in general). Evand 01:23, 22 October 2006 (UTC)

How does Sutton differentiate between rocket propulsion and jet propulsion? --Sean Brunnock 01:45, 22 October 2006 (UTC)

Please read the definition I quoted above; it's really quite clear about it. He distinguishes in the obvious fashion -- rockets have an internally stored propellant. Evand 01:59, 22 October 2006 (UTC)

So your claim that the Greeks invented rockets hinges on Sutton's definition of a rocket which you claim is the only reference which which contains the correct definition of a rocket? --Sean Brunnock 13:50, 22 October 2006 (UTC)

You'll have to show me where he makes the claim that that is the only correct reference, he merely claims that it is a reasonable definition (and you'll note it isn't word for word identical with the wikipedian definition, but it seems to be equivalent). Please stop trolling, the wikipedia is not the place for it.WolfKeeper 14:59, 22 October 2006 (UTC)

Asking for citations is not trolling. Do you have any other citations besides Sutton to back up your claims? --Sean Brunnock 15:27, 22 October 2006 (UTC)

We don't need them. The definition of rocket used in a Rocket propulsion book trumps a couple of crummy dictionaries any day. I repeat, please stop trolling.WolfKeeper 17:26, 22 October 2006 (UTC)

Actually, I'm not claiming the Greeks invented rockets. I'm saying several things. 1) Wikipedia should use a consistent definition of what is and isn't a rocket engine. 2) That definition should include solid, liquid, and hybrid rockets; ion thrusters; resistojets; monopropellant rockets; cold gas thrusters; solar, microwave, laser, and nuclear thermal rockets; nuclear and antimatter photon rockets; hobby and amateur motors, from small Estes black powder motors on up; rockets that can't ignite or otherwise operate in a vacuum. 3) It shouldn't include mass drivers; light sails; magnetic sails; Bussard ramjets; guns, cannons, and mortars; ramjets; scramjets; air-breathing pulsejets; liquid air cycle engines; maglev vehicles; space elevators; warp engines; antigravity and other reactionless drives. 4) It should be clear, simple, and concise. 5) Sutton's Rocket Propulsion Elements, a highly respected text on the subject, provides such a definition. However, I have no particular need for us to use that definition if there's a different one that meets the preceding criteria that other people would prefer. And finally, I'm saying that regardless of wording, I believe any definition that meets the preceding criteria will include the Aeolipile as a rocket. This is not the same as saying the Greeks invented rockets -- personally, I would say that they didn't invent rockets because that was the only instance, and they didn't apply the principles or study them in any real way. But that's a matter of defining "invent." IMHO, the Chinese invented rockets, but the Aeolipile was a rocket. Evand 18:09, 22 October 2006 (UTC)

original

can You tell me , Where is the original of name Rocket? Buidinhthiem 08:18, 13 May 2006 (UTC)

German Wiktionary gives as origin "rocchetta", an Italian/Spanish term for "spindle" or "mandrel", probably derived from the rocket's shape. -- Syzygy 14:33, 17 May 2006 (UTC)

It appears somebody has vandalized this. For instance, Tsiolovsky has been changed to Dick Head, and I believe it is stated that eraly rockets were really gay, and sucked alot. Hopefully, the original text of the article is preserved somewhere, and these problems can be rectified.

Megaman22 04:36, 4 December 2006 (UTC)

Reversion of Moerou toukon and IP range 59.94.96.0–59.94.106.0

Moerou toukon (block log) and IP range 59.94.96.0–59.94.106.0 are socks of an Indian nationalist editor with a history of POV-pushing,[17][18][19] citing unreliable sources,[20] and misrepresenting his sources.[21][22]
Moerou toukon has since been permanently blocked and that editor placed on revert parole by the Arbitration Committee for edit-warring and abuse of sockpuppets.

His attribution to ancient India relies heavily on a single chapter of Buchanan (2006) by Asitesh Bhattacharya and his sock edits give Bhattacharya undue weight.
Bhattacharya himself acknowledges "the prevailing view in the relevant academic community": "The respected work of scholars like Joseph Needham and general surveys such as that in the Encyclopaedia Britannica, credit Chinese alchemists with discovering in the ninth century..." (Buchanan 2006:42). JFD 20:25, 6 May 2007 (UTC)

Military definitions

It seems like there are two competing uses of "rocket." In one (which this article mainly follows) a rocket is anything propelled by a rocket engine. But apparently in military terminology a rocket is always unguided, whereas a guided weapon propelled by a rocket engine is always a "missile". Does anyone have a reliable source for this distinction that this article could cite? (Sdsds - Talk) 18:46, 5 May 2007 (UTC)

A month later, and I propose to take action on this. First, by rewriting the lead sentence to, "In general, a rocket is any vehicle or device propelled by a rocket engine." And then adding a sentence, "In the context of weapons, however, a rocket-propelled device which has some form of active guidance is not called a rocket but is instead a guided missile." This conforms to the definition listed in the guided missile article. Can anyone suggest improvements to (or criticisms of) this approach? (sdsds - talk) 23:30, 5 June 2007 (UTC)

Assessment

This article is probably better than B-Class, but it will have to go through a more formal review process to be assigned such a rating. You may wish to start with the Good Article review process, or if you are feeling particularly adventurous, the Military history WikiProject A-Class review. Best of luck! Carom 02:47, 19 August 2007 (UTC)

Need rocket costs be so high?

Off-topic WP:SOAPBOX post which was foolishly responded to rather than deleted, resulting in a very long thread

Asymptotic costs

In the ultimate data point; the only consumable is propellent (mainly fuel). R&D, personel costs and so forth tend to amortise away.

A typical fully loaded LOX/Kerosene rocket is 2% payload, 85% propellent.

Of this fuel 60% is LOX, 40% is Kerosene

LOX costs maybe $0.1/kg Kerosene costs about $1/kg

Thus the average propellent cost per kilogram of payload is (0.6*0.1 + 0.4*1)*0.85/0.02 = $20/kg

Allowing a generous 250kg per person (including lifesupport and a chair and luggage) this would be $5000/person.

Now, is this in any way realistic? On the face of it the answer is no. However consider airtravel; currently airtravel is running at about 2x the cost of fuel, so this suggests that this is acheivable with rockets as well (reusable rockets are really just a different form of aerospace vehicle.)

So, using the same multiplier, that's $10,000 per person.

This analysis assumes a *very* high rate of launch; >1000s of launches per year; reliable, mature reusable launchers, with low maintenance costs.

There is no known reason why this cannot be achieved.

You're trivializing several aspects here. First of all, rocket flight is relatively dangerous, and therefore the R&D costs, administrative personnel costs, lawyers, lawsuits, governmental red tape, real estate & construction costs, licenses, etc. etc. will contribute immensely to the overhead of any company attempting to provide rocket flight to the public. Not to mention the material and labor cost to build and test the rocket. Then there's a little thing called profit that we need to tack on as well. Air travel runs as cheap as it does because of economies of scale. Your calculation is horribly simplified and naive. 69.140.29.251 11:48, 30 August 2007 (UTC)

Other resources

low cost rockets - Scorpius - cost factor reduction of 5 to 10 - funded by NASA and USAF - successful launches already. See also this and PDF slides.

cheap access to space - just an article

[http://www.spacex.com/index.html?section=falcon&content=http%3A//www.spacex.com/falcon_i.php Falcon] 2004 launch quoted at $10,000 / kg to GTO

Popular Mechanics article on a cheaper rocket engine - tested at NASA

A set of slides

• Saturn V - $3653 / kg LEO (1967)
• Proton - $2,500 / kg LEO (current?)
• Aerojet Sea Dragon - $70 to $620 / kg LEO (1960's)
• Mc Donell Douglas MCD - $767 / kg LEO (1968/9)
• Boeing COLV 3 - $936 / kg LEO (1968)
• Boeing MCD - $1605 / kg (independent study) LEO (1970)
• Kistler K-1 - $135m NASA contract - reusable
• NASA SLI target is $2200 / kg LEO

LEO on the Cheap see Ch9

...[Do] that rocket programs include their capital costs in their launch costs [or not ?]... I'd probably need to contact someone at the ESA or NASA. Do I need to do this to make you happy?

You also keep saying that there is huge potential to advance in prices. ... but ... We've barely gotten price improvements since 1960. So, either all of the people working for all of these agencies are idiots, or you're wrong. Take your pick - you can't have them both.

It seems some think that rocket costs can be reduced. Paul Beardsell 00:13, 11 May 2004 (UTC)

Now, lets go into your rocket list. Your Saturn V cost is in 1967 dollars. Run it through inflation [23], and you'll be unpleasantly surprised to find out that the Saturn series is actually rather expensive, at about 20k$/kg. The Proton rocket cost, in addition to being in 1960s dollars, is widely accepted to be an anomaly due to the old Soviet accounting system. The Sea Dragon does not exist, never did, was based on pure MCD (Minimum Cost Design) extrapolation (which seldom ever works in engineering), and noone is proposing to build it. (I think we'd notice a rocket over three times the height of Niagra falls being built  ;) ). Truax ranted and raved about it, of course. From 1988 to 1991, the Navy worked on a smaller version of the Sea Dragon design (as SEALAR - with way less optimistic numbers); initially encouraging, it encountered major technological problems (most notably, pressurized tank failure - that's what you get when you try and build a rocket like a ship), and it was cancelled before they even attempted a single launch. Likewise, Chrystler and McDonnel-Douglas MCDs (once again, 1960s dollars) as well as Rockwell and Boeing's MCDs (including COLV) (note that your paper includes Boeing's numbers; the numbers for the MCDs were independently assessed at 1,605-2,425$/kg in 1968 dollars), were 1960s dollars. The concept of MCD has been partially rejected in favor of RLD after long analysis. Most MCD designs were somewhat unsafe, although it is true that making the rockets larger in general also offered some advantages.

Proton costs are not 1960 but, according to the slides, "current" as at 2002. But, you say, "widely accepted as an anomaly". Reference please. The Boeing MCD figures I gave were the ones for equitorial orbit from the independant study. The highest figure is for polar. Paul Beardsell 00:57, 11 May 2004 (UTC)

reference: "the low stated price of the Proton 8K82K is most likely an artefact of the Soviet system" -- http://www.theculture.org/rich/sharpblue/archives/000066.html

As for the Kistler K-1 (wow, what a jump there!), it'll be interesting to see what happens. Theoretical launch price of 17 million dollars (1997 - about 22m$ today) and payload of 4,500 kg. It is just one of many theoretical systems NASA is funding to try and bring prices down as part of SLI (the Space Launch Initiative). I think you mistook SLI for a rocket; the K1 is a rocket that is part of the SLI program. SLI is way over budget and years behind schedule. As I mentioned earlier, there are proposals in the works to try and reduce space launch via rockets to about a quarter of its current price; however, beyond that, there isn't much forseen that can lower it very much, and even reaching that level is showing to be a long and tedious process.

... And yet, here you are admitting a reduction to 25% is possible. Paul Beardsell 01:01, 11 May 2004 (UTC)

... But it seems some part of NASA is calling the rest of NASA and all the other space agencies stupid becuase they have set a target of well under $3k/kg for the SLI program. ... Paul Beardsell 00:13, 11 May 2004 (UTC)

I can't find anything about NASA funding any of Microcosm's rockets. Now, I have found things for NASA working on things like a super-compact laser with Microcosm, navigation equipment, etc, but as for rockets, I can't find a thing. Rei 23:51, 10 May 2004 (UTC)

If I can find something will you admit you are wrong? Paul Beardsell 00:13, 11 May 2004 (UTC)

This is misrepresentation. You said you don't like Ariane reliability. I said choose another rocket, then. It wasn't a discussion about cost. It's all in the log. That's a change in subject. I asked you a question: Since I demonstrated that at least one rocket system (the shuttle) does NOT repay its capital costs, why do you expect that another (the Ariane) would? Why would you expect different accounting mechanisms to be used?

My apologies about the Proton - the cited number is in 1994 dollars, which makes it about 3,200$/kg in modern dollars. However, the last launch of the 8k82k was in... 1975. You do realize that the world's space agencies would have to be idiots not to launch on the 8k82k if this were true, right? So, I'll ask again: Are They Idiots?

There's enormous pressures on projects to choose particular launchers; if you're American, you launch on an American launcher, if you are European you launch on Ariane; failing to do this gets you in serious political trouble. Also, Ariane have an excellent sales team by all accounts, and the launcher is highly optimised for GEO launches, for example it has airconditioning of the Payload, that the Proton doesn't (or didn't) have IRC. In many ways it's the easiest path just to go with Ariane, and many payloads do just that. The Proton is harder to engineer the payload for, but ultimately cheaper. There's also payload specific issues; if your payload doesn't quite fit one launcher or is much too small for another then you end up choosing an 'expensive' $/kg launcher because it ends up cheaper for your payload, that's why Pegasus is still around for example--Wolfkeeper 13:42, 27 May 2004 (UTC)

Furthermore, all of the more recent Proton rockets have cost notably more. *A Lot More*. For example, in 1994 dollars, the 8k82k/11S86 is over 14,000$/kg. In 1994 dollars. This is a *later revision* of the 8k82k. Are you going to try and claim that the Soviets were so idiotic that they took a gigantic step *backwards*? Please, don't skip these questions - answer them.

You need to consider the difference between ticket price and what you can knock them down to. The Proton is enormously cheap to produce, and hence cutting a deal is commonly done; but wouldn't ever appear on the price list.--Wolfkeeper 13:42, 27 May 2004 (UTC)

It isn't my rocket list. - you presented it as evidence, so you need to take responsibility for it. How you believe I thought the SLI was a rocket is difficult to fathom. . Because you had it in a list of rockets! If I can find something will you admit you are wrong? - About Microcosm, sure.

I thought you said rocket cost reductions were impossible. You've been repeatedly as good as calling me a fool for saying so. And yet, here you are admitting a reduction to 25% is possible. I thought I had already mentioned that, although I can't find it in the history. There have been several programs designed to try and reach that level (in fact, the space shuttle program itself was initially trying for close to that,

The Shuttle designers wanted to build a smaller, fully reusable vehicle, with no ceramic tiles, and a smaller payload, but the Government refused to pony up the cash. If they had gone with the original design- it had a robust metallic skin due to its reentry trajectory. In order to get anything built they had to make a deal with the airforce, and the airforce wanted heavier payload return to earth. This meant that more energy was dissipated during reentry, and necessitated ceramic reentry tiles. The tiles have been an enormous disappointment in cost terms; it takes a man-week to replace a single tile; and hundreds of tiles get damaged during a flight.--Wolfkeeper 11:35, 28 May 2004 (UTC)

The ironic thing is that the Shuttle designers had originally asked for less overall money; they had just wanted higher peak funding. The government had said that the higher peak funding wasn't available. They settled on a compromised Shuttle design. The operating costs with the compromise design were known to be much higher; and that's todays Shuttle; and it has ended up costing the American public many, many times over what it should have.--Wolfkeeper 11:35, 28 May 2004 (UTC)

Oh, give me a break. Back it up, and answer which shuttle designers??? (yeah, like you'd ever back it up).

FWIW it was Max Faget- the guy who's name is on the patent application for the Shuttle

There were tens of thousands of people working on the shuttle program; even a company that I used to work at (Rockwell-Collins) had a big contract for the shuttle. There were about 120 proposals for the overall design of the system, and dozens of designs for every single part in that whole craft. And, hell, the Nixon administration told NASA to reduce their requirements notably.

Why do you keep just making stuff up? Before you keep spouting out this sort of stuff, perhaps you should read about it first. Rei 16:53, 28 May 2004 (UTC)

although they were sorely disappointed

Actually, the top guy at the time recently admitted that they never thought for a microsecond that they would achieve those costs; and they weren't even trying. The launch infrastructure to achieve that is very different to what they built; but the funding they got only paid for what they built.--Wolfkeeper 11:35, 28 May 2004 (UTC)

"The top guy at the time" - for God's sake, Wolfkeeper, I thought you were lecturing about references earlier. And you can't even mention his name. Rei 16:53, 28 May 2004 (UTC)

when turnaround costs ended up being a lot more than expected - as is typical). However, you're not arguing for reduction to 25%. You're arguing for a reduction to <2% to match a first-generation space elevator. That's preposterous. Utterly ludicrous. NASA is working hard to reach that (very elusive) 25%.

NASA is funded by creating jobs in most of the states in America. The vast, vast majority of the costs of launch go on peoples wages. The way to reduce costs is to fire people that currently work on the launch platform. If they do that they lose budget and votes in the senate, and their budget gets slashed. The Shuttle is extremely labour intensive. This is a positive, not a negative, as far as the NASA organisation is concerned.--Wolfkeeper 11:35, 28 May 2004 (UTC)

It has been a slow and painful process, with very little success to show for it so far. They're not even dreaming of ever getting anywhere close to 2% with rockets.

Of course not. NASA as an organisation dreams of spending more. The individuals within NASA may dream of spending less- good luck to them; but NASA ain't going to take them there any time soon.--Wolfkeeper 11:35, 28 May 2004 (UTC)

In summary, your homework for this time is to answer the following questions:

1. Were the soviets such idiots that they couldn't figure out that they were making *gigantic* steps backwards with later rockets? Because this is what you would have to believe to accept them retiring the 8k82k for its later versions.
2. Are the people at all of the world's current space agencies such idiots as to not revive the original 8K82K for current launches?
3. Where does *anyone* at NASA currently propose using rockets to get anywhere even close to the cost of a space elevator?
4. Why would you expect different accounting mechanisms to be used between the Shuttle and Ariane?

Answer them and get back to me. Rei 16:46, 11 May 2004 (UTC)

(i) You say they are idiots not me. (ii) Ditto. (iii) It has been shown: Rockets are cheaper than elevators until a break even amount of stuff (depending upon the type of stuff) has to be moved. (iv) I wouldn't expect anything. Paul Beardsell 20:24, 11 May 2004 (UTC)

(1&2) You are dodging the issue, and I don't appreciate it. Reconcile them not being idiots with the fact that they went to what would be a far less efficient rocket. Go on - reconcile it. The only implication one can get from your argument is that they're idiots. If they're not idiots, explain why they trashed what you consider to be an incredibly efficient rocket for ones that are far, far less efficient. Do Not Dodge The Question.

(3) Actually, I showed that even with the worst case, most ridiculous assumptions, a space elevator still comes up far cheaper than any rocket, and around the cost that NASA has the *goal* of *eventually* reaching with their *optimization* of rocket technology, which is proceeding *slowly*. How can you possibly claim that "it has been shown"? What was shown was the *exact opposite*. I mean, look at the numbers! A single, first generation, minimal payload space elevator, whose components are lifted to GEO by our expensive rockets, repaying all capital costs (unlike normal space programs) in 10 years (NASA's payback is due around the year NEVER), we get $3,400/kg, one third the cost of the cheapest rocket in existance. After that, it drops to less than 200$ per kilogram - with our *first generation* elevator.

(4) Paul, you are driving me crazy by dodging the questions. Don't give me that "I wouldn't expect anything". I raised a legitimate issue. The space shuttle, as I demonstrated and has not contested, does not repay its capital costs. Do you contest this? If you do contest it, you must demonstrate that, with its 500-600 million dollar turnaround cost, that the turnaround cost doesn't equal about 10,000$ a pound for payload. If you do not contest it, but you still consider Ariane to be repaying its capital costs, then you must expect there to be different accounting. Which is it? Don't dodge my questions here - you dodged 1, 2, and 4 (and claimed something flatly contradicting the numbers shown in our discussion for #3), and I don't appreciate it one bit. Rei 21:55, 11 May 2004 (UTC)

You put words in my mouth. You insist I answer questions of the type "Have you stopped beating your wife?" You spend days attacking me because I suggested rocket costs could be reduced and this is now your position: Good, I have persuaded you. But you wish to continue. As far as I am concerned what I wanted to show has been shown. I do not want to continue this argument with you. Paul Beardsell 23:08, 11 May 2004 (UTC)

While I completely disagree with your assessment, and I find my questions to be perfectly reasonable (you haven't addressed any of the issues I presented related to the proton's cost (why would they abandon it if it were so cheap???), to the accounting (why would they use different accounting methods???, etc), as long as you'll drop your "Its easy to lower rocket prices and a sizable percentage of people with any sort of qualifications on the subject whatsoever think they'll get anywhere close to that of a space elevator" attitude, I'm fine with that. Rei 23:46, 11 May 2004 (UTC)

Whoever is being quoted in the above paragraph it is not me. Nor is it a proper characterisation of what I have said. Paul Beardsell 00:41, 12 May 2004 (UTC)

It's called paraphrase, Paul. If that's not what you've been arguing, please sum up your argument for us. Rei 16:05, 12 May 2004 (UTC)

The consensus seems to be that there is a potential to reduce rocketry costs to perhaps 25% of today's costs. Some private companies are getting involved and they are presumably hoping to make a profit out of their rocketry offerings so it is rational to assume capital financing costs must be factored in to their figures. Even if this potential to reduce rocketry costs is speculative, even if it takes decades to realise it seems fairer to compare the speculative costs of the future elevator with the speculative costs of future rocketry.

Paul Beardsell 10:58, 12 May 2004 (UTC)

Also, just a quick reply to Paul: If they're developing rockets under a NASA contract, they're not expecting to get their capital costs repayed in launch costs. NASA gives contracts to companies based on how much it costs the company to develop, and then NASA owns the product. I know because I used to work for Rockwell-Collins, and they had a scandal a while back while working on a project for the shuttle (the shuttle contract had no limit, and so other projects started charging hours to it). Unless these contracts are somehow completely different and they're (strangely) paying the company in installments based on how much use it gets, they're not expecting anything along the lines of capital cost repayment from launch costs. Now, for independent organizations like Scaled Composites and the Da Vinci Project, they would probably be repaying their capital costs - but their payloads are so tiny, I doubt they'll be rivalling anything for bulk lifting capacity per dollar (DaVinci carries 400kg; I'm not sure how much SpaceShipOne will carry). Rei 16:05, 12 May 2004 (UTC)

Good Article Review Completed

I've now re-reviewed this article as requested following my decision to place it on hold.

GA review (see here for criteria)

1. It is reasonably well written.

   a (prose): b (MoS):

2. It is factually accurate and verifiable.

   a (references): b (citations to reliable sources): c (OR):

3. It is broad in its coverage.

   a (major aspects): b (focused):

4. It follows the neutral point of view policy.

   a (fair representation): b (all significant views):

5. It is stable.

   

6. It contains images, where possible, to illustrate the topic.

   a (tagged and captioned): b lack of images (does not in itself exclude GA): c (non-free images have fair use rationales):

7. Overall:

   a Pass/Fail:

At this time, I do not believe that this article qualifies for Good Article status. The checklist above shows which arrears are of concern. My primary concern with this article is that significant portions remain unreferenced. For example, the second half of "Spread of rocket technology", and "Early manned rocketry" is completely unreferenced despite saying 'according to some sources' which could be considered using Weasel Words too. Large sections of "Modern Rocketry" are also unreferenced. In "Types", there's only one reference for six paragraphs. A good guide is that if there isn't a reference every two paragraphs, there's probably not enough references.

The editors of this article have clearly worked hard to bring it up to the standard it is at now, and should be proud of that work, and it isn't going to take too much work to satisfy all of the criteria for GA Status. It just isn't there yet. Feel free to re-nominate it when these issues are addressed :)

If you believe my review has been in error, please feel free to take it to a GA Review. Thank you for your hard work so far :) Pursey ^{Talk | Contribs} 00:28, 8 September 2007 (UTC)

Bias

There's a strong bias to liquid rockets, space exploration, & ballistic missiles. Black powder rockets (like FFARs & RP-3s) are much more common & much more-often used... Trekphiler (talk) 19:26, 23 March 2008 (UTC)

Then go finds some reliable sources, and start writing! - BillCJ (talk) 19:34, 23 March 2008 (UTC)

When adding material I try to avoid this, which particular bits are seen as strongly biased?- (User) WolfKeeper (Talk) 00:18, 24 March 2008 (UTC)

Wan Hu

I'm unconvinced by this story. It sounds like it was invented in 1945...- (User) WolfKeeper (Talk) 03:29, 18 December 2007 (UTC)

what about the steam bird story? —Preceding unsigned comment added by 69.139.156.214 (talk) 23:31, 29 June 2008 (UTC)

Some comments

Great section on early solid fuel rockets. See also: Frank Winter's book "The First Golden Age of Rocketry: Congreve and Hale Rockets of the Nineteenth Century" (which may be where the information and references are from).

Interplanetary rocketry: Goddard wrote a paper on interplanetary navigation in 1907, submitted but declined by Scientific American. Many letters about photographing Mars, etc, but unfortunately he rarely published. In 1912, Esnault-Pelterie published rocket theory and calcuations about reaching the Moon and planets. The first correct treatment of interplanetary transfer orbits is in 1921 by Vetchinkin and later in 1925 by Hohmann (who gets the credit, sorry Russians). Mention Jules Verne? He actually had a huge impact on people's thinking. Almost all the rocketry pioneers mention reading Verne. His moon capsule was launched by cannon, but slowed by rockets, so probably the first mention of interplanetary rocketry.

I might expand the small section about Goddard, as I have just finished reading most of his collected papers (researching for a book I'm writing). He introduced supersonic nozzle, rocket stages, gyroscopic stabilization, first liquid fuel engine, etc.

Oberth is a strange figure, not really present that much in Germany, and not that many really new ideas in his work. He was generally represented by the unscrupulous Rudolf Nebel in the VfR, and the Army had no interest in him at all. Klaus Riedel was the brains behind VfR in my opinion, and of course the Army V-2 effort had hundreds of professional engineers like engine designer Thiel. I think von Braun and Ley talk about Oberth a lot because they want to create an all-encompassing history that is pure German.

As I read more of Oberth's work, I see that he dismissed or ignored prior work and went to great lengths to claim fundamental ideas were actually his own or someone else's of German race. A technically smart man, but it is disappointing to see this behavior. Willy Ley has a nationalistic bias, but he is absolutely careful and honest about facts. For example, Oberth states that Ganswindt thought of rockets in space before Verne's 1870 novel and well before Tsiolkovsky. Ley, who knew Ganswindt and interviewed him, tries to track this down and finds no evidence of any thought of space propulsion before 1890. Ganswindt, Ley points out, believed that rockets push against the air and could not be used in space. In another example, Oberth rejects Goddard's use of the de Laval nozzle as unworkable, then presents an essentially identical design as his own. DonPMitchell (talk) 16:46, 16 July 2008 (UTC)

I think he was more of a populariser or promoter, some sources seem to imply he worked independently, but that may not be true. Whether he genuinely did anything new I don't know. There is the Oberth effect but I don't know how that came to be named after him- it may be because he emphasised discussions of the additive properties of delta-v with respect to staging and this carried over (but I'm guessing).- (User) WolfKeeper (Talk) 17:11, 16 July 2008 (UTC)

Yes, I think it is impossible to know who thought of what when. Oberth claims to have had the ideas long before he published them. Goddard had notebooks with rocketry ideas going back to 1907. This is why date of publication is generally accepted as defining priority. I've read Oberth's 1929 book, and I am about to get (an original copy!) of his 1923 booklet, so I plan to look closely at his claims and what he said about Goddard in 1923. Goddard made no secret of the fact that he thought Oberth was a plagiarist and a racist, the two men really dislike each other strongly. DonPMitchell (talk) 17:56, 18 July 2008 (UTC)

On the V-2, I've seen claims that more people died producting it (slave labor) than by being blown up by it. That would be nice factoid in the article if you find a reference.

The section on WW II should not just talk about the V-2. GALCIT did important research on combustion stability, which allowed the US to fix some German designs that had never worked before (e.g., the Redstone engine). The Corporal missile work started near the end of the war. In the Soviet Union, work on rocket planes and JATO was ongoing during the war, and of course their Katyusha rocket launchers were important. DonPMitchell (talk) 23:51, 15 July 2008 (UTC)

I expanded the section on Goddard a couple days ago. Hard to know where to put this information, I should probably move it down to pre-WWII. Goddard wrote about interplanetary rocketry, but mostly in letters to his patrons. In a 1920 letter, he discusses the ideas of photographing planets or even sending messages to planets if they have intelligent life (still something deemed possible for Mars in his day). DonPMitchell (talk) 02:26, 24 July 2008 (UTC)

Energy efficiency of airbreathing jet engines

I couldn't find a number for this, so I did some mild OR I'm afraid, or at least I did a calculation based on available data, I didn't come to any major conclusions based on it. Hope that's OK.

The SFC at cruise for a CF-6 engine is about 17.1 g/kN.s i.e. it takes 17.1 g of aviation fuel to produce 1kN for 1 second. That's a fuel power of 17.1 e-3 * 43.1 MJ (jet fuel) = 737 kW

A Boeing 747-400 cruises at 913km/h, which is 254 m/s. So for each 17.1g of fuel the CF-6 is generating a power of 1000 * 254 (force*distance/s = energy/s)= 254 kW

So I make that an overall efficiency of 34%. Close enough to 35%.- (User) Wolfkeeper (Talk) 20:39, 14 November 2008 (UTC)

rocket artillery

obviously a big topic in itself, with many of its own pages already, but nothing is mentioned here after medieval times. i added a sentence about mlrs and smerch in the current section, but perhaps somebody with more knowledge than me could mention it some more--Mongreilf (talk) 20:36, 21 December 2008 (UTC)

History of rockets

This part of the article seems to be over 30k in and of itself. I'm therefore proposing to copy it to a separate article, and reduce the coverage as much as possible in this article (which probably isn't much actually, I'm not planning any violent reductions). Comments?- (User) Wolfkeeper (Talk) 22:28, 26 December 2008 (UTC)

• I would be inclined to support that. I'd suggest the new article be entitled History of rocketry. --GW_Simulations_{User Page | Talk} 22:56, 26 December 2008 (UTC)

I'm thinking maybe History of rockets rather than rocketry?- (User) Wolfkeeper (Talk) 00:25, 29 December 2008 (UTC)

OK, I did it. I removed 7k from the article.- (User) Wolfkeeper (Talk) 00:30, 31 December 2008 (UTC)

i do not know

i dont know anything because my teacher gave this to me with out telling us what to do —Preceding unsigned comment added by 72.74.119.44 (talk) 21:59, 7 April 2009 (UTC)

Scientists' beliefs

I have removed this sentence:

"He [Goddard] proved that a rocket would work in a vacuum, which many scientists did not believe at the time."

Newton's laws were well-known and universally accepted by scientists long before Goddard's time. Perhaps the scientists never thought about how the laws would work in a vacuum, but I'd like to see a source. --Bowlhover (talk) 04:30, 13 March 2009 (UTC)

Might the issue have been combustion in a vaccum, whether the rocket's engine itself would function despite using an oxidizer? Just a semi-educated guess. Whetever it was, you're right that it needs to be properly sourced.

Some scientists didn't understand the reaction principle- they thought you need to push off an external material, like the air or the ground to move about, rather than pushing off of the exhaust.- (User) Wolfkeeper (Talk) 21:30, 22 June 2009 (UTC)

Citation style proposal.

Because this requires a significant amount of effort, I'd like to check consensus before working on rationalizing the citation style in this article.

My intention is put all references sources in the References section, enclosed in the relevant citation templates (template:Cite book etc.) Possibly broadly split into book and web. The Notes section to contain {{reflist}}, and the main text to use harvnb inline.

This way the article text isn't broken up with citation templates when editing, page number references are easy to include, the citation templates are all in one place, and each generated entry in the Notes section will be a clickable link to the full citation in what will be a long list of citations.

See the existing "Sutton" references as an example.

Your comments are welcome Hohum (talk) 21:39, 30 June 2009 (UTC)

• What is the advantage of {{harvnb}} over {{cite book}}? --GW… 21:45, 30 June 2009 (UTC)

In the main body of the article, Cite xxx templates for every reference means that:

1. It's difficult to read the main text when editing, as it's broken up with full templates at every point a reference is used. Harvnb can be concise.
2. When using the same book (or whatever) multiple times, but for different pages, the Notes section will have the entire text of the citation repeated many times, which is makes the section difficult to read, and very long. Harvnb can give short entries in the Notes section.
3. When maintaining citations, you need to find where it is in the main text in order to edit it. This is especially awkward when trying to maintain multiple citations (adding isbn's etc).
4. Harvnb utilises the anchor points generated by Cite templates to form a clickable link between the Note entry and the entry in the References section.

All together, I beleive it makes the article easier to edit and maintain, and the Notes and References section easier to read. Hohum (talk) 22:01, 30 June 2009 (UTC)

Exhaust always hypersonic?

Recent changes - I added the qualifier "can" in a previous version of the phrase "The action of the exhaust against the inside of combustion chambers and expansion nozzles accelerates the gas to hypersonic speed". Are rocket exhausts always hypersonic, even in fireworks for instance? Hohum (talk) 17:39, 18 July 2009 (UTC)

Well, I couldn't find a reference so I ran the mixture for gunpowder (75% potassium nitrate, 15% charcoal, 10% sulphur) through cpropep web and got an exhaust velocity of about 1300m/s. I think that's just about still hypersonic (hypersonic has no completely formal definition).- (User) Wolfkeeper (Talk) 18:03, 18 July 2009 (UTC)

Fatality risks

From recent edits, I see there has been some disagreement about the risk of spaceflight. The following link may be of help. http://www.thespacereview.com/article/36/2 (Hohum ^@) 15:41, 24 April 2010 (UTC)

imho such detail should be elsewhere, this article should confine itself to what a rocket is, what it was& is used for and how it works ClemMcGann (talk) 15:58, 24 April 2010 (UTC)

You can't really completely separate the danger of a rocket from the rocket. The article is about rocket vehicles anyway, it's not just about rocket engines or whatever. Space rockets are the main class of rocket vehicles, and manned vehicles are a major, important subset.- Wolfkeeper 16:17, 24 April 2010 (UTC)

I think the risks are worth including, but not at length. Space accidents and incidents seems to be the relevant place for expanded content. (Hohum ^@) 17:34, 24 April 2010 (UTC)

GA Review for Rocket - On Hold

I've begun my review of this article as per the request for review to promote it to Good Article status:

GA review (see here for criteria)

1. It is reasonably well written.

   a (prose): b (MoS):

2. It is factually accurate and verifiable.

   a (references): b (citations to reliable sources): c (OR):

3. It is broad in its coverage.

   a (major aspects): b (focused):

4. It follows the neutral point of view policy.

   a (fair representation): b (all significant views):

5. It is stable.

   

6. It contains images, where possible, to illustrate the topic.

   a (tagged and captioned): b lack of images (does not in itself exclude GA): c (non-free images have fair use rationales):

7. Overall:

   a Pass/Fail:

At this time, the review has been placed On Hold for a maximum period of seven days.

This is due to 'citation needed' tags in the first section of the article, as well as the lead to the article containing no references. In particular, the statement that the history of rockets goes back to the 13th century.

Other than these referencing issues, I cannot see any other large problems at this time. I'd suggest that the editors of this article could bring this article up to scratch within seven days, and as such, I've not failed the article at this time. Please leave me a note on my talk page when the article is ready for review. :) Pursey 16:58, 5 September 2007 (UTC)

In the Section "in antiquity", in the 2nd paragraph in the eighth sentence, should the word "heard" be replaced by the word "hurled"?128.170.224.13 (talk) 18:44, 4 October 2010 (UTC)MichaelJDaley

Mass ratios erroneously calculated

The article section entitled Mass ratio contains a table of erroneous values for the mass ratios and mass fractions of a list of rockets and rocket-powered vehicles. Mass ratio as applied to the calculation of the change-in-velocity potential of a rocket can only be applied one stage at a time. It refers only to the ratio of the mass of a stage before the engine burn to the mass after the engine burn, the difference being just the mass of propellant consumed. You can't take the gross mass of the rocket and divide it by the final mass after all of the stages are finished burning, while ignoring all of the inert mass that has been jettisoned in between. No rocket has a mass ratio of 39.9 or a mass fraction of 97.5%. Those numbers are utterly meaningless.Magneticlifeform (talk) 03:34, 18 October 2010 (UTC)

Misuse of sources

This article has been edited by a user who is known to have misused sources to unduly promote certain views (see WP:Jagged 85 cleanup). Examination of the sources used by this editor often reveals that the sources have been selectively interpreted or blatantly misrepresented, going beyond any reasonable interpretation of the authors' intent.

Please help by viewing the entry for this article shown at the cleanup page, and check the edits to ensure that any claims are valid, and that any references do in fact verify what is claimed. Tobby72 (talk) 19:19, 12 September 2010 (UTC)

The misinterpretation of sources reflected on the Jagged 85 cleanup page seems to continue in the current write-up in the In Antiquity section of the article. Without sighting creditable references, the author of the section invokes evidence of the origins of rockets and cannons hundreds of years before either appears in the voluminous known records of the history of Chinese technology. The Chinese did keep good records and produced multiple copies of said records using fired-clay movable type printing presses before 1000 A.D., hundreds of years before printing presses appeared in Europe. It was illegal to destroy such records. If the knowledge of the past had been lost in antiquity, it would be different, but when a country's history is well documented, you should be able to prove what you say if you go against the record. So someone needs to step up and document it if they are claiming true rockets existed before 1200 A.D. or cannons before 1300 A.D. Unsubstantiated assumptions that a particular word meant rocket or cannon or that fire arrows are rockets rather than simple incendiary devices need to be avoided. This goes on even in official NASA and NASM (National Air & Space Museum) circles, where histories of this or that are often written by unqualified political appointees who make things up as needed to hide their inadequate knowledge of the subject. That's why verifiable references are an absolute must. It's easy to insert them. Just click on the little open-book logo that appears above as you edit the text of the article, and it will prompt you for the reference. It inserts the bracketed number in the text and puts the bracketed number plus reference in the footnotes below. It's that simple. You don't even have to tell it what number to use.Magneticlifeform (talk) 18:33, 18 October 2010 (UTC)

POV safety section

I tagged the "safety.." section with a POV tag, pointing to specific statements. At the moment this section's tone comes across as "Rockets aren't dangerous, no need to worry, really", and is clearly down-playing the danger. How dangerous rockets are should be quantified in a neutral way, rather than qualitatively assessed, as is currently the case. In particular, the section really needs to acknowledge the hundreds (probably thousands) of people who have died in rocket-related accidents. So I've added the POV tag for now; hopefully this can be fixed. Mlm42 (talk) 04:56, 2 December 2010 (UTC)

Well, rockets in the form of fireworks are clearly somewhat dangerous, but they're routinely launched. Or emergency flares, they are rockets- are they dangerous? It obviously depends on the type of rocket and how it's used. Safety is never a binary thing. Cars kill lots and lots and lots of people, are they unsafe?- Sheer Incompetence (talk) Now with added dubiosity! 03:16, 4 December 2010 (UTC)

Hey Sheer, emergency flares are not rockets. Most public fireworks are not rockets. They are popped out of a short tube, like a mortar, and coast upward before exploding. The accident rate with amateurs experimenting with energetic materials is quite high. It is not like driving a car. A few milliliters of hydrogen peroxide if set off will produce a large enough volume of 900^oF gas to fatally burn someone standing hear it. Let's not give kids reading the article the wrong idea about how everyday world rockets are. It's something best not learned the hard way.Magneticlifeform (talk) 01:19, 9 December 2010 (UTC)

LOL- think of the children!!!! I agree that some fireworks are mortars, but rocket fireworks are very, very common. Also [24] distress rockets and rocket line throwers are standard pieces of equipment.- Sheer Incompetence (talk) Now with added dubiosity! 20:20, 9 December 2010 (UTC)

Incidentally, a few millilitres of hydrogen peroxide is not nearly enough to do that, (it only produces a few litres of hot gas at standard pressure), and the kind of hydrogen peroxide you need to do that is HTP, which is a special order chemical from chemical suppliers; the normal stuff is very dilute and won't react very quickly at all. In other words, every single thing you're saying is essentially untrue.- Sheer Incompetence (talk) Now with added dubiosity! 21:55, 9 December 2010 (UTC)

I was not speaking hypothetically about the danger of hydrogen peroxide. There have been deaths from its use by amateurs, including one from the use of no more than the quantity used to fill a fountain pen draw-tube. 5cc of high test peroxide yields about 18 liters of 900^oF gas. A third of that hot gas is oxygen--at sufficient temperature to ignite clothing instantaneously. The 30% peroxide available from chemical supply houses is not that difficult to concentrate. I do not need to lie about it as you imply. I worked with HTP and other propellants for most of my professional engineering career. Safe rocketry is possible but requires respect for the materials used. Certainly rockets are not uncommon. Anyone can drive to Wyoming and buy all the bottle rockets they want or order a bunch of Estes engines through the mail. Flying rockets is fun. Making them from scratch is not for unprepared beginners. That's all I'm saying. I advocate caution so those getting into rocketry have fun without undue risk. Magneticlifeform (talk) 01:41, 11 December 2010 (UTC)

So, the reason I tagged this section as POV, is that if noone provides references for these specific statements, I'm going to remove them. It's been over a week now, and references for these statements have not been provided. Mlm42 (talk) 03:07, 11 December 2010 (UTC)

Looks okay now, so I've removed the tag. Mlm42 (talk) 00:33, 7 January 2011 (UTC)

Change of First Picture in Article

I am suggesting that the picture of the Soyuz Rocket be changed to A V-2 rocket or something earlier in creation — Preceding unsigned comment added by The Mentlegen (talk • contribs) 17:07, 5 February 2012 (UTC)

Incorrect definition

" A rocket is a missile, spacecraft, aircraft or other vehicle which obtains thrust from a rocket engine. In all rockets, the exhaust is formed entirely from propellants carried within the rocket before use. "

In this article, it is considered that a spacecraft is a rocket. I find this extremely incorrect. Although that may be true if you just consider the shape of the thing sufficient to consider it a rocket, it isn't true if you look at the engine used.

I think we should differentiate air-breathing engines (ie solid fuels) from non-air breathing engines (ie using liquid hydrogen + liquid oxygen). In my view, a rocket is a leisure device, unable to travel in space, since it uses solid fuels. Consequently, the V-2 rocket is then also not considered a rocket.

Please relook at the terminology we use, and provide reliable sources for this. 91.182.21.28 (talk) 11:15, 9 February 2012 (UTC)

Dear KVDP, this sort of utterly ignorant comment is why I find it impossible to take seriously a single thing that you post.

"unable to travel in space, since it uses solid fuels." Just start with that one. I won't even grace it with citing refs contra, it's that ludicrously wrong. Andy Dingley (talk) 11:49, 9 February 2012 (UTC)

Propulsive efficiency

0% efficiency at 0 speed? How does it ever get off the launchpad at 0% efficiency. And what about the spinning Earth, it's not really at 0 speed. If the shuttle in orbits turns ship towards retrograde and fires OHMS engines does it lose efficiency? C'mon.98.165.15.98 (talk) 09:12, 25 April 2011 (UTC)

This is a weird one. If I understand this correctly, it's because 0.5 m v^2 means you need no energy to start moving at very low speed, because when v is small, v^2 is negligible. The effect is that with a rocket you accelerate at the same rate even from zero, even though the efficiency is zero when at precisely zero speed, but that's what it needs to be there. So I think it makes sense, although it is odd appearing when you first see it. Cars have problems because they don't produce zero energy at zero speed, the engine makes energy all the time, so they have to have a clutch which scrubs off that extra energy, otherwise sticking it in gear causes the car to jerk forwards due to this. Steam engines don't spin their engines when stationary, so they're smoother starting and don't need a clutch, but I believe that they also produce zero power at zero speed.Planetscared (talk) 15:30, 9 February 2012 (UTC)

"Long serpent" rocket launcher interpretation not justified

The interpretation of the quiver of fire arrows as a rocket launcher seems highly unlikely to be correct, for several reasons. First of all, a closed quiver is hardly suitable for launching rockets. Second, the size of the black powder cylinders is far too small to be an effective propulsive device for arrows of the relative size shown, especially given the very limited capability of black powder as propellant. The drawing shows nothing more than a standard quiver box containing ordinary arrows with small attached cylinders of black powder incendiary to light fires. The fuse is merely to light the incendiary before releasing the arrow from a standard bow. The Cambridge book clearly stated that the drawing depicted "fire arrows" and also stated that the Wujing Zongyao did not contain any descriptive text that translated to "rocket" as opposed to "fire arrows". The description of this drawing as a rocket launcher is unsubstantiated. — Preceding unsigned comment added by 166.70.15.248 (talk) 07:22, 4 August 2013 (UTC) Magneticlifeform (talk) 07:37, 4 August 2013 (UTC)

'Rocket' for Laymen

I suspect this is an excellent article for a certain audience, but for a layman it's excessive on the techno/science and lite to basic information.

In reading 'Rocket' article, the 'Spaceflight' section seems to provide the only clue as to the speed of the fastest rocket: "...rockets are particularly useful when very high speeds are required, such as orbital speed (Mach 24+[99])."

I know that Mach 24+ (over 29,000 km/h; 18,000 mph) is probably not the fastest because in the Wiki's "List of Vehicle Speed Records" article I discovered that the 'New Horizon' probe achieved 'Earth-exiting speed of 58,536 (36,373)'. Btw, I also checked 'Rocket Engine' and still no answer.

I hope you see my point. The topic is "Rocket". To a layman, we are wondering what rockets do? Sure, we want to know how they fly even though most of us learned about Newton's 3rd Law in elementary school. But a layman might want to know how high they fly? how far? how fast?

I'm impressed with the detail of the article. Clearly there's great subject matter expertise, but I don't think there's enough thought about informing non-scientific readers.

I think Wiki does a GREAT job and have no question about that, and I support it with my donations each year. SuperHawks 18:43, 7 May 2015 (UTC) — Preceding unsigned comment added by WendyStarbuck (talk • contribs)

I've tried to change the lead section to answer your questions; there's technically no upper speed limit on (multistage) rockets, they just get more and more expensive; and there's no altitude limit as you would normally think of it- it's possible to send a rocket to another solar system (although it would take thousands of years to reach its destination with current technology.)GliderMaven (talk) 20:42, 25 August 2015 (UTC)

I removed the last sentence you added and tweaked the verbiage a bit; please let me know what you think. I think the sentence about dropping efficiency, while of course totally true, wasn't quite right for the lead section of a top-level article. Rockets have peak efficiency at their effective exhaust velocity, ~4400 m/s for a H2/O2 rocket. That might exceed the novice reader's expectation of "much higher speeds." VQuakr (talk) 08:09, 26 August 2015 (UTC)

Let's unprotect. Indefinite protection was never called for in the first place.

This page was protected indefinitely a year and a half ago for very weak reasons. According to the edit adding the protection: "A very large proportion of editing consists of vandalism followed by reverts, and has done for many years." The trouble is, that's true for every page on Wikipedia, and it's no justification. There's nothing controversial about this subject that attracts any more vandalism than usual. Restricting IPs from editing unduly eliminates the myriad of fixups done by them. Wikipedia is based on the idea that "anyone" can edit, specifically IPs. There's no good reason to continue with protection here.

The "over" protection was also put in place without any due process as far as I can tell. There's no discussion of a vandalism problem here on the talk page at all. There's no mention of any form of the word "protection", and only one use of a form of "vandalism" (in 2006!). It looks like nothing led up to it. The admin who put the protection in place made no discussion on this page, it looks like he just came along and did it with that vague unsupported assertion. I didn't see any mention of "Rocket" on his talk page either (archive 57). The admin has a "This user fights vandalism." tag on his page. That's fine enough, but I think he went too far in this case. If there was a specific problem going on at the time, a non-indefinite protection might have been called for. But, "indefinite" was serious overkill.

Regarding vandalism, this article can and should tough-it-out like every other Wikipedia article. It should allow IPs to do their good works. If a little vandalism has to be reverted every now and then, so be it. Every other article does it. It's just not that hard.

KnucklesNuclear (talk) 02:59, 25 August 2015 (UTC)

First step is to talk to the protecting admin, JamesBWatson. --NeilN ^{talk to me} 03:02, 25 August 2015 (UTC)

You're an admin, why don't you unprotect it? The PA here seems to be a fine fellow and we may contact him in due course, but a PA should never have to be consulted. That's a silly rule. The facts are what the facts are and you can act on them. This undue "protection job" needs to be fixed. You're able to fix it, so fix it. Be bold for crying out loud.  :-) KnucklesNuclear (talk) 04:54, 25 August 2015 (UTC)

@KnucklesNuclear: Thank you for expressing your concerns. I will try to clarify my reasons for the protection, and give you my opinions on some of the issues that you raise.

1. Being "bold" means being bold in making a first action: it does not mean that everyone should feel free to revert what anyone else does without consulting them and being willing to discuss the issue. That is why we have a policy against edit-warring.
2. Rightly or wrongly, Wikipedia policy is that, unless there are good reasons for making an exception, an administrator does not reverse another administrator's action without the original administrator having been consulted first. I was not involved in making that policy, but I suggest there are at least the following two advantages in following that policy. Obviously, you will judge for yourself how far you agree with them. (a) The administrator who took the action in the first place may have know of circumstances which are not obvious to others, in which case, while reversing the action may seem right, it may actually be a mistake. I have certainly known many cases where I have seen what has seemed to be a perfectly clear cut case, but on consulting the original administrator, have found that there are factors which I had not known of, and which make a considerable difference. (b) If we took the line that administrators should feel free to revert any other administrator's action that they disagreed with without consultation, it would open up the opportunity for disruptive wheel-warring.
3. Even if you think that policy should be changed so that administrators can feel free to "boldly" revert other administrators' actions without consultation or discussion, I am not clear why you were unwilling to consult me NeilN suggested it. Even if you are totally convinced that you are right, so much so that whatever I say cannot possibly have any chance whatever of making any difference, I don't see that inviting me to express my opinion can do any harm.
4. I can only assume that your remarks about "without any due process" mean that you are one of the editors who are under the impression that policy is that administrators are allowed to take action only following discussions. That is not the case, but you are of course free to suggest a change in policy if you think it would be beneficial. However, I find it difficult to understand how you reconcile that view with your urging another administrator to "be bold" and take unilateral action without discussion, and without even consulting the person whose action you wish to see reverted. Are you sure that you aren't, perhaps unconsciously, wanting an administrator to act "boldly" without discussion only when the action contemplated is one you like, while requiring an administrator to refrain from taking action without discussion when the action in question is one you don't like?
5. When I placed semi-protection on the article, it had six times previously been protected, and every time the reason was stated to be "vandalism". Those protections spanned a period of a little more than six years, and the seven protections were placed by seven different administrators.
6. It is certainly not true that "A very large proportion of editing consists of vandalism followed by reverts, and has done for many years" is, as you say, "true for every page on Wikipedia". I have just opened 10 random articles, and for each one checked the last 10 edits, giving an overall sample of 100 edits. 7 of those 10 articles had no vandalism at all in their last 10 edits, while the other 3 articles each had one vandalism edit, making an overall rate of 3% vandalism edits. I would say that is reasonably typical; if anything, I would guess that the average rate of vandalism is probably less than 3%, but in any case it isn't substantially higher than that. I also checked the latest 30 edits of the article Rocket before I placed the protection. Of those 30, 11 edits were unambiguous vandalism, and another 3 were unconstructive edits, perhaps vandalism or perhaps good-faith but misguided edits. Each of those 14 edits has been reverted by some editor, making 28 edits which were either uncontructive editing or reverting of unconstructive editing. If we ignore the 3 doubtful edits, that means that 73% of editing was either vandalism or reverting of vandalism, while including the 3 doubtful edits, 93% of editing was disruptive editing or reverting of that disruptive editing. Among the same 30 edits, the number of constructive edits by non-autoconfirmed editors was zero.
7. You say "There's nothing controversial about this subject that attracts any more vandalism than usual." I agree that there is nothing controversial about the article, but for some reason (I have no idea why) it does attract far more than the usual amount of vandalism, as I have indicated above. (Incidentally, controversial articles attract more than the average amount of some types of disruptive editing, such as edit-warring and editing to promote a point of view, but they do not necessarily attract a particularly large amount of vandalism. Sometimes it is obvious why a particular article attracts a lot of vandalism, sometimes it isn't, but being on a controversial topic does not seem to be a major factor.) You say "If a little vandalism has to be reverted every now and then, so be it. Every other article does it." That is true of most other articles, but not "every other article": there is a small minority of articles which attract an enormously disproportionate amount of vandalism, and this is one of them. Goodness knows why, but it is.
8. I very strongly dislike protection of pages, because there is always a likelihood that it will cause inconvenience for some legitimate editors. For that reason I never place protection on any page without first thoroughly investigating the history of the page in question, and I go ahead with the protection only if it is clear that the amount of damage it will prevent overwhelmingly exceeds the likely amount of collateral damage. Investigating the history of this article all the way back to before the first block was imposed almost eight years ago, I found enormous amounts of vandalism by non-autoconfirmed editors. Each time that the article was protected, the amount of vandalism dropped to zero or virtually zero; each time the protection ran out, the amount of vandalism returned to high levels; each time, there was then a considerable amount of vandalism, sometimes for a long period, until some administrator or other became aware of it and protected the article again. Meanwhile, the amount of constructive editing by non-autoconfirmed editors was minute: less than one percent of the number of edits attributable to vandalism and reverting of vandalism. Short-term protection makes sense when it seems that disruptive editing is likely to be temporary, and will die out after a short time, but in the case of an article where vandalism is endemic and persistent over the course of many years, returning each time protection runs out, it is difficult to see why one should choose to keep letting it come back over and over again. If there is a consensus among a number of editors that we should go back to protecting the article sporadically, and letting vandalism return every time the protection runs out, then I shall be perfectly willing to remove the protection, but I am not willing to do so on the basis of one editor more or less demanding that protection be removed, without even wishing to hear my case first. The editor who uses the pseudonym "JamesBWatson" (talk) 12:21, 25 August 2015 (UTC)

@JamesBWatson: thanks for your reply here. I do not share the OP's opinion that the 2014 semi-pro was inappropriate, but as an uninvolved editor who does some patrolling-type activities, I would be fine with seeing this article go to PC or move-semi protection for a while and keeping it on my watchlist to see if, for whatever reason, this article is less of a vandalism target now than it was 18 months ago. I can always take it to WP:RPP if it is clear that the IP's are causing a lot more trouble than help. VQuakr (talk) 16:20, 25 August 2015 (UTC)

It seems the protecting admin has been duly contacted.

VQuakr, thanks for your support, well, "semi-support" at least.  :-) I'm a little confused by some terms. What does "go to PC" mean? I don't mind if moves are restricted, as long as IPs can edit a page normally. That system where edits must be approved (what ever it's called) seems a reasonable compromise, but even that is against the "spirit of Wikipedia" I think. It's generally to be avoided if possible. Also, given that no evidence was cited for the article being more vandal-attractive than normal, I don't think even that "edit-approval" system has been justified.

Let's allow IPs to edit, then tough-out whatever vandalism comes along like everyone else.

KnucklesNuclear (talk) 17:52, 25 August 2015 (UTC)

@KnucklesNuclear: hi, sorry yes my last post was a little cryptic because JamesBWatson was the intended audience and I knew he would understand my shorthand. As you appear to have guessed, "go to PC" refers to pending changes, a protection level in which edits by very new or IP editors are approved before they are "live." More generally, our protection policy is at WP:PROTECTION. As an aside, your repeated assertions of "lack of evidence" regarding the previous protection level seems generally unhelpful - the page protection history clearly shows a long-term pattern of slowly escalating periods of protection. It is entirely reasonable to support another go at unprotection without labeling previous protections as unjustified, so let's keep it positive, no? VQuakr (talk) 19:43, 25 August 2015 (UTC)

I can see how it might look immaterial to argue that it was originally unjustified. I'm not asking for support of that opinion. I'm just using the idea that it was unjustified to support a move to remove protection. I think it's a pretty fair and reasonable place to start. BUT! If you're up for supporting the normalization of protection without consideration of the circumstances of it's imposition, then I'll take it! I totally support you in that!  :-) KnucklesNuclear (talk) 21:57, 25 August 2015 (UTC)

Looking back through the archives, it's difficult to guess why people make the edits they do, but if I was forced to guess, I would think it's mostly children making exuberant edits to the article. The topic tends to attract children, and some of them find the 'edit' button and stuff happens. Making it semi-protected means the children have to create an account and in most cases the account will be blocked shortly afterwards. I certainly hope we never run out of children, but the vast majority of children that try to edit this article aren't going to be at a developmental and educational stage where they could make a positive contribution- but all power to any that can. I don't think unprotecting this article is the way to go.GliderMaven (talk) 21:02, 25 August 2015 (UTC)

•  Comment: WP:Pending changes would not, in my opinion, be appropriate for articles with a history of vandalism by unconfirmed editors—pending changes protection can be much more restrictive than the current level of protection of this article (possibly limiting the ability to have edits take immediate effect to fewer than 20,000 editors)—in no way can pending changes be characterized as a "compromise". On the other hand, any unconfirmed editor can request an edit on a protected article talk page (See Talk:Ernest Hemingway for examples). And any IP editor can create an account (providing much greater anonymity than using an IP address), make ten edits on unprotected articles, and, after four days, directly edit a semi-protected article. — Neonorange (talk) 20:41, 25 August 2015 (UTC)

How easy it might be to create an account (and then wait) is immaterial. The perspective is against WP policy of being an encyclopedia that anyone (specifically IPs) can edit. "Edit Requests" are awkward, time consuming, and humiliating, and they're also against WP policy of being an encyclopedia that anyone can edit.

I've used PC in the past as an IP and I thought it went pretty smoothly! :-) As long the current indef protection is removed and a PC replacement has an expiration date, I think that's okay, not perfect, but okay.

KnucklesNuclear (talk) 22:14, 25 August 2015 (UTC)

Hey! I just discovered such a thing as a "protection log". (Doh!) If the protections are believed justified, it seems there were spates about one per year starting in late 2007, then there was a wide gap from early 2010 to late 2013. All of the spates were handled with protection no longer than a month, most of them with a week or less. That hardly counts as the kind of high-volume never-ending-and-never-will-end vandalism that might justify indefinite protection. It's just not that hard to impose a short-term protection every now and then as demanded.

Extraordinary protection requires extraordinary evidence. Such a big and permanent indefinite protection should have strong evidence that there's no way to handle it any other way. Those old vandalisms were seldom present for more than a few minutes, some less than a minute! Their impact was extremely low, while the impact of prohibiting IPs is very high. If it actually gets too tough and fixing vandalism becomes unduly time consuming, there's always a better way than permanent exclusion of IPs, expiring protection has worked fine in the past. Maybe an expiring PC could be a new suitable alternative (only when called for of course). Indefinite restrictions are almost never justifiable. If something actually needed to be re-protected every 6-months, that's just too easy to do. Saving that trivial labor never justifies the permanent exclusion of IPs.

KnucklesNuclear (talk) 22:04, 25 August 2015 (UTC)

If you read what I wrote above, you will see that I pointed out that during the intervals when the article was unprotected, there was an enormous amount of vandalism. What you are writing seems to be based on the belief that the sporadic protections with long gaps during which the article was unprotected solved the problem, but even a couple of minutes checking the editing history will show that that was far from being the case. Indefinite protection was not, as you seem to think, done in order to save the "trivial labor" of continually re-protecting for short times, it was done because continually re-protecting for short times did not work. I thought I had made that clear, but evidently I had failed to convey what I tried to convey. The editor who uses the pseudonym "JamesBWatson" (talk) 08:25, 26 August 2015 (UTC)

• I am willing to try "protected changes" if there is consensus for it. That would have both advantages and disadvantages. Protected changes works quite well in some situations, but in a case such as this one, it is never totally successful. One of the problems is that, while pending changes prevents vandalism from being publicly visible in the article, it does nothing whatever to reduce the amount of work that is used up in checking and reverting that vandalism. Since almost all editing is either vandalism or reverting of vandalism, with pending changes in operation it is still the case that a significant amount of editors' time is taken up on this task instead of being employed in more constructive work.

• Although the idea of Wikipedia as an idealistic venture where everybody is allowed to edit without any hindrance or inconvenience as a matter of beautiful principal is an attractive one, it is not, in fact, the reality. Wikipedia allows (almost) anyone to edit not because that's a beautiful ideal, but because it is a convenient way to get work done on the encyclopaedia. (Jimmy Wales and Larry Sanger introduced the system of allowing open editing only after their original attempt to create a free encyclopaedia (Nupedia) with careful vetting and use of selected expert editors had failed to get enough work done.) We try to allow everyone to edit as far as reasonably possible, but the primary aim is to build the encyclopaedia, and when allowing everyone to edit without restriction conflicts with that aim, it is, unfortunately, often necessary to compromise. I know full well that the compromises we have to make can be a nuisance to some editors, as I have experienced it myself. I started editing without an account, and created an account only when one day I found that I couldn't edit at the local library because the library's IP address was blocked. Naturally, that was irritating, but I accepted that it was necessary, and I created an account. That meant inconvenience for me, as I had to wait until I could create an account on another computer, but that inconvenience for me, and no doubt for a number of other editors in the same situation, was a small price to pay for the advantage of stopping the vast amounts of vandalism that have come every time the blocks on that library's IP address have expired. Exactly the same principal applies to protection of an article, except that it is on a much smaller scale, as it only prevents editing of that one article, rather than preventing any editing at all, which was what I experienced, and also because protection of an article does not force an editor to find some other computer where he or she can create an account. The bottom line is that we make decisions on the basis of an assessment of what will on balance be most beneficial to the project to build the encyclopaedia. If there is a general support for the idea that pending changes would on balance be a better way of dealing with the problems on this article than semi-protection, then I will be perfectly willing to try it. So far there have been opinions expressed both for and against the change. The editor who uses the pseudonym "JamesBWatson" (talk) 08:57, 26 August 2015 (UTC)

I'm okay with PC too - with an expiration date. A long expiration date is fine if you prefer (6 months?). It's the indefiniteness that's the real problem. If there really is a long term high level of vandal-attractiveness, that means once every seven months or so, some admin will make another long term protection, which is easy to do. That's actually a very small work load considering the benefits of liberation from the oppression of an indefinite protection.

KnucklesNuclear (talk) 18:19, 28 August 2015 (UTC)

So, are you going to do it? PC? KnucklesNuclear (talk) 03:57, 1 September 2015 (UTC)

A separate pump-fed engine?

Pump-fed engine redirects to Rocket#Costs and economics but there's only a vestigal mention of pump-fed engine in there. Could we unlink the redirect and have a proper article (or even a stub) for the pump-fed rocket engines instead of a redirect that explains exactly nothing? Sharpfang (talk) 19:39, 3 November 2015 (UTC)

Surely we have an article on liquid-fuelled rocket engines? (We don't as yet, just one on liquid-fuelled rockets) That's a reasonable place for a section within it on pump-fed engines. Andy Dingley (talk) 19:49, 3 November 2015 (UTC)

I retargeted it to Liquid-propellant rocket, which does contain some discussion of the use of turbopumps, as a stopgap. Feel free to re-retarget if a new article is created on the rocket engines themselves. VQuakr (talk) 20:02, 3 November 2015 (UTC)

Citations re Hermann Oberth

These seem not suited for the External Links section, but I wanted to get them into the discussion history in case anyone ever wants to check my work. (Please do.)

• "The Prophet of Space Travel—Hermann Oberth", Werner Von Braun, not dated, original source unknown

• "Early Space Station Activities", information provided by NASA, not dated, author unknown; excerpt (apparently from explanatory material included in an English translation of Die Rakete...: "Oberth suggested a permanent station supplied by smaller rockets on a periodic basis and suggested rotation of the vehicle to produce an artificial gravity for the crew. Such a station, he said, could serve as a base for Earth observations, as a weather forecasting satellite, as a communications satellite, and as a refueling station for extraterrestrial vehicles launched from orbit."

• "Hermann Oberth: Father of Space Travel", Christian Staange, 1996-2000, article concludes with a print biography

--Munge 22:05, 5 Mar 2005 (UTC)

... GliderMaven (talk) 00:34, 13 February 2016 (UTC)