Talk:Herschel Space Observatory

Understandability

IMHO the article should briefly explain what part of the spectrum the telescope is looking at and what can be seen there. It is too technical right off, it needs a understandable introduction. 85.197.16.138 (talk) 04:29, 14 May 2009 (UTC)

I took a crack at it. Pb8bije6a7b6a3w (talk) 21:06, 29 April 2013 (UTC)

Detector temperatures

Only SPIRE and PACS have detector temperatures below 2K. HIFI has a detector temperature between 2 and 3K.

Image

The image reflects the design forseen until 2001, i.e. a totally outdated mounting of the subreflector and the old service module design. It should be replaced by one of the current images from the ESA site. According to the Terms of Use this should be possible. —Preceding unsigned comment added by 81.173.179.240 (talk) 12:59, 25 January 2009 (UTC)

Unfortunately the terms of the ESA copyright notice (specifically those related to commercial use) are considered to be too restrictive to meet Wikipedia's strict requirements as to what constitutes 'free media'. See {{Non-free ESA media}}. The images could plausibly be used under fair use though. Modest Genius ^talk 17:35, 19 April 2011 (UTC)

Verb Tense

This whole article is written in the future tense, as if it has not been updated since Hershcel started operating. The mismatch between tense and reality is nw even more acute now that Hershel is about to run out of liquid helium and cease operation.

So there is a lot more than just the image that is out of date. 64.134.239.71 (talk) —Preceding undated comment added 23:24, 12 March 2013 (UTC)

decibel

What do you use as reference value when calculating dB's? 10^-12 ? —Preceding unsigned comment added by 94.209.25.26 (talk) 20:05, 14 May 2009 (UTC)

I agree; this statement "able to detect signals as weak as −63dB" does not seem to have any easily-decipherable meaning. dB are a relative measurement, not an absolute measurement. -63 dB compared to what? Geoffrey.landis (talk) 15:15, 5 February 2010 (UTC)

Clarification of resolution

The spectrometer has a resolution between 1000 and 5000 [clarification needed] and is ...

If this is a dimensionless unit there needs to be some explanation (a link to another article, perhaps), else it appears that a dimension is missing. This is not in my field, so I do not know the technical merits of the text, only that in reading it seemed a bit odd. - Leonard G. (talk) 00:09, 16 May 2009 (UTC)

Looking at the WIkipedia article on spectral resolution, (which is how that line now reads), it is clear that spectral resolution is measured in the same units as wavelength. So if 1000 to 5000 really are the spectral resolution, the figures need units. OTOH, the same article mentions how closely related spectral resolution is to resolving power, which really is a pure number. Comparison with the resolving power of STIS (same article) suggests 5000 really is a reasonable value for the resolving power, not the resolution (STIS has a resolving power of 5900).

Similarly, the article gives the sensitivity of a detector in dB. But this makes little or no sense. Surely dBm were meant?

64.134.239.71 (talk) —Preceding undated comment added 23:31, 12 March 2013 (UTC)

Summary of the article

Hello, I have moved the "launch and orbit" § to the end of the article.

It seems to me more logical in the life of the satellite.

In addition, this § will have much more details in the near future when the satellite will be submited to manoeuvres to be put in its final Lissajous orbit.

Then, new § will logicaly appear : tests in orbit, activation of the payloads, and finally a very large paragraph with results of the experimenations (many years of very interesting informations, I hope.--Friendly, aaaf-wiki (talk) 04:53, 16 May 2009 (UTC)

That makes sense. I've done the same for Planck. — Aldaron • T/C 05:08, 16 May 2009 (UTC)

The lead paragraph needs to be reworded, though. You have to get a fair way through the article before it becomes clear this is now a flying mission. 79.199.60.61 (talk) 21:35, 16 May 2009 (UTC)

Hifi camera failed?

It is implied by a couple sites (below) that the Hifi camera has not responded for about a month - however I can only see it reported from a few Dutch media (and don't really speak Dutch). Can anyone find enough confirmation to consider it verifiable?

http://www.nos.nl/nosjournaal/artikelen/2009/9/4/040909_ruimtecamera.html http://www.rtvnoord.nl/nieuws/indexwm.asp?actie=totaalbericht&pid=84653

Willhsmit (talk) 23:03, 4 September 2009 (UTC)

No other news source seems to be talking about this, which is odd, but it is apparently true. the Herschel Operations Blog specifically talks about it and the possibility that they will have to switch to the backup set of electronics. So I gather the camera itself is okay, its just the electronics that went down. — Huntster (t @ c) 00:39, 5 September 2009 (UTC)

I heard it was some redundant DC converter that failed.--Stone (talk) 06:15, 5 September 2009 (UTC)

The dutch website talks about a second camera, I think they do not have a second camera, but only a second electronics box.--Stone (talk) 06:26, 5 September 2009 (UTC)

You are correct, Stone. No second camera, just secondary electronics. — Huntster (t @ c) 17:07, 5 September 2009 (UTC)

The proble is always to find out if the problem is a statistic error, than it is OK to switch to the secondary unit, but if this is a systematic problem of the satelite than the second circuit has only a limited life time.--Stone (talk) 18:10, 5 September 2009 (UTC)

The thing is still not switched on.--Stone (talk) 10:45, 1 October 2009 (UTC)

Was there any consideration of a warm mission as WISE and Spitzer had

Was there any consideration of a warm mission as WISE and Spitzer had after their coolant was exhausted ? - Rod57 (talk) 16:27, 13 March 2021 (UTC)

Where is it now - what orbit

After decommissioning (at SEL2?) it was just left to drift randomly away into a near-earth heliocentric orbit ? - Rod57 (talk) 12:51, 7 July 2021 (UTC)