Jump to content

Chandrayaan-2

This is a good article. Click here for more information.
From Wikipedia, the free encyclopedia

Chandrayaan-2
Vikram lander mounted on top of orbiter inside cleanroom.
Mission type
OperatorISRO
COSPAR ID2019-042A Edit this at Wikidata
SATCAT no.44441
Websitewww.isro.gov.in/chandrayaan2-home-0
Mission duration
  • Orbiter: ~ 7.5 years (planned);
    5 years, 2 months, 19 days (elapsed)
  • Vikram lander: ≤ 14 days (planned);[1][2]
    0 days (landing failure)
  • Pragyan rover: ≤ 14 days (planned);[2]
    0 days (not deployed)
Spacecraft properties
ManufacturerISRO
Launch massCombined (wet): 3,850 kg (8,490 lb) [3][4][5]
Combined (dry): 1,308 kg (2,884 lb) [6]
Orbiter (wet): 2,379 kg (5,245 lb) [4][5]
Orbiter (dry): 682 kg (1,504 lb) [6]
Vikram lander (wet): 1,471 kg (3,243 lb) [4][5]
Vikram lander (dry): 626 kg (1,380 lb)[6]
Pragyan rover: 27 kg (60 lb) [4][5]
PowerOrbiter: 1000 watts[7]
Vikram lander: 650 watts [8]
Pragyan rover: 50 watts
Start of mission
Launch date22 July 2019, 09:13:12 UTC[9]
RocketLVM3 M1 [10][11]
Launch siteSatish Dhawan Space Centre Second Launch Pad
ContractorISRO
Lunar orbiter
Orbital insertion20 August 2019, 03:32 UTC [12][13]
Orbital parameters
Periselene altitude100 km (62 mi) [14]
Aposelene altitude100 km (62 mi)
Lunar lander
Spacecraft componentRover
Landing date6 September 2019, 20:23 UTC [13][15]
Landing sitenear-Lunar south pole (intended)
Tiranga Point 70°52′52″S 22°47′02″E / 70.8810°S 22.7840°E / -70.8810; 22.7840
(between Manzinus C and Simpelius N craters) (crash site)

Mission Insignia

Chandrayaan-2 (pronunciationⓘ; from Sanskrit: Chandra, "Moon" and yāna, "craft, vehicle") is the second lunar exploration mission developed by the Indian Space Research Organisation (ISRO) after Chandrayaan-1. It consists of a lunar orbiter, the Vikram lunar lander, and the Pragyan rover, all of which were developed in India. The main scientific objective is to map and study the variations in lunar surface composition, as well as the location and abundance of lunar water.

The spacecraft was launched from the second launch pad at the Satish Dhawan Space Centre in Andhra Pradesh on 22 July 2019 at 09:13:12 UTC by a LVM3-M1 rocket. The craft reached lunar orbit on 20 August 2019. The Vikram lander attempted a lunar landing on 6 September 2019; the lander crashed due to a software error.

The lunar orbiter continues to operate in orbit around the Moon. A follow-up landing mission, Chandrayaan-3, was launched in 2023 and successfully performed a lunar landing.

History

[edit]

On 12 November 2007, representatives of the Roscosmos and ISRO signed an agreement for the two agencies to work together on the Chandrayaan-1's follow-up project, Chandrayaan-2.[16][17] ISRO would have the prime responsibility for the orbiter, rover and the launch by GSLV, while Roscosmos was to provide the lander.[18] The Indian government approved the mission in a meeting of the Union Cabinet, held on 18 September 2008 and chaired by Prime Minister Manmohan Singh.[19] The design of the spacecraft was completed in August 2009, with scientists of both countries conducting a joint review.[20]

Although ISRO finalised the payload for Chandrayaan-2 on schedule,[21] the mission was postponed in January 2013 and rescheduled to 2016 because Russia was unable to develop the lander on time.[22][23][24] In 2012, there was a delay in the construction of the Russian lander for Chandrayaan-2 due to the failure of the Fobos-Grunt mission to Mars, since the technical issues connected with the Fobos-Grunt mission which were also used in the lunar projects including the lander for Chandrayaan-2 needed to be reviewed.[23] The changes proposed by Roscosmos necessitated increase in lander mass and required ISRO to decrease mass of its rover and accept some reliability risk.[25][18] When Russia cited its inability to provide the lander even by a revised time-frame of 2015 due to technical and financial reasons, India decided to develop the lunar mission independently.[22][26] With new mission timeline for Chandrayaan-2 and an opportunity for a Mars mission arising with launch window in 2013, unused Chandrayaan-2 orbiter hardware was repurposed to be used for the Mars Orbiter Mission.[27]

Chandrayaan-2 launch had been scheduled for March 2018 initially, but was first delayed to April and then to October 2018 to conduct further tests on the vehicle.[28][29] On 19 June 2018, after the program's fourth Comprehensive Technical Review meeting, a number of changes in configuration[30] and landing sequence[31] were planned for implementation which increased the gross lift-off mass of spacecraft from 3,250 kg to 3,850 kg.[32] Initially an uprated GSLV Mk II[33][34] was the chosen launch vehicle for Chandrayaan-2 but this increased spacecraft mass and issues with launch vehicle upratement[35] forced the launch vehicle to be switched to more capable LVM3.[30] Issues with engine throttling were found during testing[36] pushing the launch to the early 2019[37] and later two of the lander's legs received minor damage during one of the tests in February 2019 delaying the launch even further.[38][39]

Chandrayaan-2 launch was scheduled for 14 July 2019, 21:21 UTC (15 July 2019 at 02:51 IST local time), with the landing expected on 6 September 2019.[40] However, the launch was aborted due to a technical glitch and was rescheduled.[9][41][42] The launch occurred on 22 July 2019 at 09:13:12 UTC (14:43:12 IST) on the first operational flight of a GSLV MK III M1.[43]

On 6 September 2019, the lander during its landing phase, deviated from its intended trajectory starting at 2.1 km (1.3 mi) altitude,[44] and had lost communication when touchdown confirmation was expected.[45][46] Initial reports suggesting a crash [47][48] were confirmed by ISRO chairman K. Sivan, stating that "it must have been a hard landing".[49] The Failure Analysis Committee concluded that the crash was caused by a software glitch.[50] Unlike ISRO's previous record, the report of the Failure Analysis Committee has not been made public.[51]

Chandrayaan-2 orbiter performed a collision avoidance manoeuvre at 14:52 UTC on 18 October 2021 to avert possible conjunction with Lunar Reconnaissance Orbiter. Both spacecraft were expected to come dangerously close to each other on 20 October 2021 at 05:45 UTC over the Lunar north pole.[52]

Objectives

[edit]

The primary objectives of the Chandrayaan-2 lander were to illustrate the ability to soft-land and operate a robotic rover on the lunar surface.

The scientific goals of the orbiter are

Design

[edit]

The name Chandrayaan means "mooncraft" in Sanskrit and most other Indian languages.[56][57] The mission was launched on a GSLV Mk III M1 with an approximate lift-off mass of 3,850 kg (8,490 lb) from Satish Dhawan Space Centre on Sriharikota Island of Andhra Pradesh.[3][11][14][31] As of June 2019, the mission has an allocated cost of ₹ 9.78 billion (approximately US$141 million which includes ₹ 6 billion for the space segment and ₹ 3.75 billion as launch costs on GSLV Mk III M1.[58][59] Chandrayaan-2 stack was initially put in an Earth parking orbit of 170 km (110 mi) perigee and 40,400 km (25,100 mi) apogee by the launch vehicle.[60]

Orbiter

[edit]
Chandrayaan-2 orbiter at integration facility

The Chandrayaan-2 orbiter is orbiting the Moon on a polar orbit at an altitude of 100 km (62 mi).[61] It carries eight scientific instruments; two of which are improved versions of those flown on Chandrayaan-1. The approximate launch mass was 2,379 kg (5,245 lb).[4][5][21][62] The Orbiter High Resolution Camera (OHRC) conducted high-resolution observations of the landing site prior to separation of the lander from the orbiter.[2][61] The orbiter's structure was manufactured by Hindustan Aeronautics Limited and delivered to the ISRO Satellite Centre on 22 June 2015.[63][64]

  • Dimensions: 3.2 × 5.8 × 2.2 m [8]
  • Gross lift-off mass: 2,379 kg (5,245 lb) [3]
  • Propellant mass: 1,697 kg (3,741 lb) [6]
  • Dry mass: 682 kg (1,504 lb)
  • Power generation capacity: 1000 watts[8]
  • Mission duration: ~ 7.5 years, extended from the planned 1 year owing to the precise launch and mission management, in lunar orbit [1][65]

Vikram lander

[edit]
Rover Pragyan mounted on the ramp of Vikram lander
Images of the Earth captured by Chandrayaan-2 Vikram lander camera LI4[66]

The mission's lander is called Vikram (Sanskrit: Vikrama, lit. 'Valour' [67]) Pronunciationⓘ named after cosmic ray scientist Vikram Sarabhai (1919–1971), who is widely regarded as the founder of the Indian space programme.[68] The Vikram lander detached from the orbiter and descended to a low lunar orbit of 30 km × 100 km (19 mi × 62 mi) using its 800 N (180 lbf) liquid main engines. After checking all of its on-board systems it attempted a soft landing that would have deployed the rover, and performed scientific activities for approximately 14 Earth days. Vikram crash-landed during this attempt.[1][47] The combined mass of the lander and rover was approximately 1,471 kg (3,243 lb).[4][5]

The preliminary configuration study of the lander was completed in 2013 by the Space Applications Centre (SAC) in Ahmedabad.[22] The lander's propulsion system consisted of eight 58 N (13 lbf) thrusters for attitude control[69] and five 800 N (180 lbf) liquid main engines derived from ISRO's 440 N (99 lbf) liquid apogee motor.[70][71] Initially, the lander design employed four main throttle-able liquid engines, but a centrally mounted fixed-thrust engine [72] was added to handle new requirements of having to orbit the Moon before landing. The additional engine was expected to mitigate upward draft of lunar dust during the soft landing.[31] The four throttle-able engines of lander were capable of throttling between range of 40 to 100 percent incrementally in steps of 20%.[73]Vikram was designed to safely land on slopes up to 12°.[74][75]

Some associated technologies include:

  • A high resolution camera, Laser Altimeter (LASA)[76]
  • Lander Hazard Detection Avoidance Camera (LHDAC)
  • Lander Position Detection Camera (LPDC)[77]
  • Lander Horizontal Velocity Camera (LHVC), an 800 N throttleable liquid main engine [63]
  • Attitude thrusters
  • Ka-band radio altimeters[78][79]
  • Laser Inertial Reference and Accelerometer Package (LIRAP)[80] and the software needed to run these components.[2][61]

Engineering models of the lander began undergoing ground and aerial tests in late October 2016, in Challakere in the Chitradurga district of Karnataka. ISRO created roughly 10 craters on the surface to help assess the ability of the lander's sensors to select a landing site.[81][82]

  • Dimensions: 2.54 m × 2 m × 1.2 m (8 ft 4 in × 6 ft 7 in × 3 ft 11 in) [8]
  • Gross lift-off mass: 1,471 kg (3,243 lb) [3]
  • Propellant mass: 845 kg (1,863 lb) [6]
  • Dry mass: 626 kg (1,380 lb)
  • Power generation capability: 650 watts
  • Mission duration: ≤14 days (one lunar day) [2]

Pragyan rover

[edit]
Main article: Pragyan (Chandrayaan-2)
Pragyan rover of the Chandrayaan-2 mission

The mission's rover was called Pragyan (Sanskrit: Prajñāna, lit. 'Wisdom' [83][84]) Pronunciationⓘ)[83][85] with a mass of 27 kg (60 lb), and would have operated on solar power.[4][5] The rover was to move on six wheels, traversing 500 m (1,600 ft) on the lunar surface at the rate of 1 cm (0.39 in) per second, perform on-site analyses and send the data to the lander, which would have relayed it to the Mission Control on the Earth.[21][58][62][86][87]

For navigation, the rover would have used:

  • Stereoscopic camera-based 3D vision: two 1 megapixel, monochromatic navcams in front of the rover to provide the ground control team a 3D view of the surrounding terrain, and help in path-planning by generating a digital elevation model of the terrain.[88] IIT Kanpur contributed to the development of the subsystems for light-based map generation and motion planning for the rover.[89]
  • Control and motor dynamics: the rover has a rocker-bogie suspension system and six wheels, each driven by independent brushless DC electric motors. Steering is accomplished by differential speed of the wheels or skid steering.[90]

The expected operating time of Pragyan rover was one lunar day, or ~14 Earth days, as its electronics were not designed to endure the frigid lunar night. However, its power system has a solar-powered sleep/wake-up cycle implemented, which could have resulted in longer service time than planned.[91][92] Two aft wheels of the rover had the ISRO logo and the State Emblem of India embossed on them to leave behind patterned tracks on the lunar surface.[93][94]

  • Dimensions: 0.9 × 0.75 × 0.85 m [8]
  • Power: 50 watts
  • Travel speed: 1 cm/sec
  • Mission duration: ~14 Earth days (one lunar day)

Science payload

[edit]
Mission overview

ISRO selected eight scientific instruments for the orbiter, four for the lander,[3][95][96] and two for the rover.[21] While it was initially reported that NASA and European Space Agency (ESA) would participate in the mission by providing some scientific instruments for the orbiter,[97] ISRO in 2010 had clarified that due to weight restrictions it will not be carrying foreign payloads on the mission.[98] However, in an update a month before launch,[99] an agreement between NASA and Indian Space Research Organisation (ISRO) was signed to include a small laser retroreflector from NASA to the lander's payload to measure the distance between the satellites above and the microreflector on the lunar surface.[100][101]

Orbiter

[edit]
Chandrayaan-2 orbiter in clean-room being integrated with payloads
Chandrayaan-2 composite

The orbiter has several scientific payloads.[1][3][96]

  • The Chandrayaan-2 Large Area Soft X-ray Spectrometer (CLASS) from the ISRO Satellite Centre (ISAC), which makes use of X-ray fluorescence spectra to determine the elemental composition of the lunar surface.[102]
  • The Solar X-ray monitor (XSM) from Physical Research Laboratory (PRL), Ahmedabad, primarily supports CLASS instrument by providing solar X-ray spectra and intensity measurements as input to it. Additionally these measurements will help in studying various high-energy processes occurring in the solar corona.[21][103]
  • The Dual Frequency L-band and S-band Synthetic Aperture Radar (DFSAR) from the Space Applications Centre (SAC) for probing the first few metres of the lunar surface for the presence of different constituents. DFSAR is expected to provide further evidence confirming the presence of water ice, and its distribution below the shadowed regions of the Moon.[21][104] It has lunar surface penetration depth of 5 m (16 ft) (L-band).[65][96]
  • The Imaging IR Spectrometer (IIRS) from the SAC for mapping of lunar surface over a wide wavelength range for the study of minerals, water molecules and hydroxyl present.[21][105] It features an extended spectral range (0.8 μm to 5 μm), an improvement over previous lunar missions whose payloads worked up to 3 μm.[65][106][107]
  • The Chandrayaan-2 Atmospheric Compositional Explorer 2 (ChACE-2)[108] Quadrupole Mass Analyzer from Space Physics Laboratory (SPL), designed for carry out a detailed study of the lunar exosphere.[21]
  • The Terrain Mapping Camera-2 (TMC-2) from SAC for preparing a three-dimensional map essential for studying the lunar mineralogy and geology [21][109]
  • The Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere – Dual Frequency Radio Science experiment (RAMBHA-DFRS) by SPL for the studying electron density in the lunar ionosphere[110]
  • The Orbiter High Resolution Camera (OHRC) by SAC for scouting a hazard-free spot prior to landing. Used to help prepare high-resolution topographic maps and digital elevation models of the lunar surface. OHRC has a spatial resolution of 0.32 m (1 ft 1 in) from 100 km (62 mi) polar orbit, which is the best resolution among any lunar orbiter mission to date.[96][111][112][113]

Vikram lander

[edit]

The payloads on the Vikram lander were:[3][96]

Pragyan rover

[edit]

Pragyan rover carried two instruments to determine the abundance of elements near the landing site:[3][96]

Discoveries and results

[edit]

The orbiter, which is still active, did experiments on Lunar Atmospheric composition, trace elements, and more

  • Detection of sodium: In October 2023, the orbiter discovered an abundance of sodium on the Moon.[123] The moon is shown to have a tail of Sodium atoms thousands of Kilometers long. Due to phenomena like photon stimulated desorption, solar wind sputtering, and meteorite impacts, sodium atoms gets knocked off the surface.[124] Solar radiation pressure accelerates the sodium atoms away from the Sun, forming an elongated tail toward the antisolar direction. Using the large area X-raySpectrometer, CLASS, the probe has spotted and mapped sodium on the Moon.
  • Hydroxyl and Water molecules: The Chandrayaan-1 probe detected water on the Moon for the first time. Chandrayaan-2 detected Water, as well as Hydroxyl ions on the Moon, August 2022. It distinguished between these two with the aid of IIRS (Imaging Infrared Spectrometer). Between 29 and 62 degrees north latitude, the probe detected the presence of these two molecules. Along with this, it also observed that the sunlit regions contain higher concentrations of these two.
  • Distribution of Gas in Lunar Atmosphere: Chandra Atmospheric Composition Explorer-2, detected Argon-40 in Lunar exosphere. The distribution of Ar-40 has significant spatial heterogeneity. The NASA probe, LADEE, detected Argon near the Equatorial region, but Argon far from that, was detected for the first time. There are localised enhancements (termed as Argon bulge) over several regions including the KREEP (potassium (K), rare-earth elements, and phosphorus (P)) and South Pole Aitken terrain.
  • Presence of Rare elements: Chandra's Large Area Soft X-ray Spectrometer (CLASS), detected magnesium, aluminium, silicon, calcium, titanium, iron etc. It also examined and detected minor elements – chromium and manganese, for the first time. The findings have paved the path for adding knowledge about the magmatic evolution of the Moon, its nebular conditions and much more.
  • Solar X-ray Monitor (XSM), has witnessed a huge amount of microflares outside the active regions of the Sun for the first time.
  • The DFSAR instrument studied the subsurface features of the Moon, detected signatures of the sub-surface water-ice, mapped lunar morphological features in the polar regions in high resolution.
  • The TMC 2, which is conducting imaging of the Moon at a global scale, found interesting geologic signatures of lunar crustal shortening, and identification of volcanic domes. The OHRC, mapped Moon With a resolution of 25 cm at 100 km altitude.
  • DFRS experiment, studied the ionosphere of the Moon, which is generated by the solar photo-ionisation of the neutral species of the lunar tenuous exosphere. The experiment showed that Moon's ionosphere has a plasma density of the order of 10^4 cm^3, in the wake region which is at least one order of magnitude more than that is present in the day side.

Mission profile

[edit]
Animation of Chandrayaan-2
Geocentric phase
Selenocentric phase
Lunar landing phase
Overall motion of Chandrayaan-2
   Earth ·    Moon ·    Chandrayaan-2

Launch

[edit]
Chandrayaan-2 lifting off on 22 July 2019 at 02.43 PM IST

The launch of Chandrayaan-2 was initially scheduled for 14 July 2019, 21:21 UTC (15 July 2019 at 02:51 IST local time).[40] However, the launch was aborted 56 minutes and 24 seconds before launch due to a technical glitch, so it was rescheduled to 22 July 2019.[9][41] Unconfirmed reports later cited a leak in the nipple joint of a helium gas bottle as the cause of cancellation.[42][125][126]

Finally Chandrayaan-2 was launched on board the LVM3 M1 launch vehicle on 22 July 2019 at 09:13:12 UTC (14:43:12 IST) with a better-than-expected apogee as a result of the cryogenic upper stage being burned to depletion, which later eliminated the need for one of the apogee-raising burns during the geocentric phase of mission.[43][127][128] This also resulted in the saving of around 40 kg fuel on board the spacecraft.[129]

Immediately after launch, multiple observations of a slow-moving bright object over Australia were made, which could be related to upper stage venting of residual LOX / LH2 propellant after the main burn.[130][131]

Geocentric phase

[edit]
Chandrayaan-2's trajectory

After being placed into a 45,475 × 169 km parking orbit by the launch vehicle,[43] the Chandrayaan-2 spacecraft stack gradually raised its orbit using on-board propulsion over 22 days. In this phase, one perigee-raising and five apogee-raising burns were performed to reach a highly eccentric orbit of 142,975 × 276 km[132] followed by trans-lunar injection on 13 August 2019.[133] Such a long Earth-bound phase with multiple orbit-raising manoeuvres exploiting the Oberth effect was required because of the limited lifting capacity of the launch vehicle and thrust of the spacecraft's on-board propulsion system. A similar strategy was used for Chandrayaan-1 and the Mars Orbiter Mission during their Earth-bound phase trajectory.[134] On 3 August 2019, the first set of Earth images were captured by the LI4 camera on the Vikram lander, showing the North American landmass.[66]

Selenocentric phase

[edit]

After 29 days from its launch, the Chandrayaan-2 spacecraft stack entered lunar orbit on 20 August 2019 after performing a lunar orbit insertion burn for 28 minutes 57 seconds.[135] The three-spacecraft stack was placed into an elliptical orbit that passed over the polar regions of the Moon, with 18,072 km (11,229 mi) aposelene and 114 km (71 mi) periselene.[136] By 1 September 2019, this elliptical orbit was made nearly circular with 127 km (79 mi) aposelene and 119 km (74 mi) periselene after four orbit-lowering manoeuvres [137][138][139][140] followed by separation of Vikram lander from the orbiter on 07:45 UTC, 2 September 2019.[141]

Planned landing site

[edit]
Main article: Pragyan (Chandrayaan-2)
Landing site [142] Coordinates
Prime landing site 70°54′10″S 22°46′52″E / 70.90267°S 22.78110°E / -70.90267; 22.78110
Alternate landing site 67°52′27″S 18°28′10″W / 67.87406°S 18.46947°W / -67.87406; -18.46947
The flat highland between craters Manzinus C and Simpelius N was the planned landing zone for the Vikram lander.

Two landing sites were selected, each with an ellipse of 32 km × 11 km (19.9 mi × 6.8 mi).[142] The prime landing site (PLS54) was at 70.90267°S 22.78110°E (600 km (370 mi) from the south pole,[143]) and the alternate landing site (ALS01) was at 67.87406° South 18.46947° West. The prime site was on a high plain between the craters Manzinus C and Simpelius N,[144][145] on the near side of the Moon.

Failed landing attempt

[edit]
Location of the Vikram lander impact site
Ejecta field around Vikram lander impact site
Before and after images of the impact site
Before and after images of the impact site

Vikram began its descent at 20:08:03 UTC, 6 September 2019 and was scheduled to land on the Moon at around 20:23 UTC. The descent and soft-landing were to be performed by the on-board computers on Vikram, with mission control unable to make corrections.[146] The initial descent was considered within mission parameters, passing critical braking procedures as expected, but the lander's trajectory began to deviate at about 2.1 km (1.3 mi) above the surface.[147][148] The final telemetry readings during ISRO's live-stream show that Vikram's final vertical velocity was 58 m/s (210 km/h) at 330 m (1,080 ft) above the surface, which a number of experts noted, would have been too fast for the lunar lander to make a successful landing.[45][149][150] Initial reports suggesting a crash[47][48] were confirmed by ISRO chairman K. Sivan, stating that "it must have been a hard landing".[49][151][152] However, it contradicted initial claims from anonymous ISRO officials that the lander was intact and lying in a tilted position.[153][154]

Radio transmissions from the lander were tracked during descent by analysts using a 25 m (82 ft) radio telescope owned by the Netherlands Institute for Radio Astronomy. Analysis of the doppler data suggests that the loss of signal coincided with the lander impacting the lunar surface at a velocity of nearly 50 m/s (180 km/h) (as opposed to an ideal 2 m/s (7.2 km/h) touchdown velocity).[3][46] The powered descent was also observed by NASA's Lunar Reconnaissance Orbiter (LRO) using its Lyman-Alpha Mapping Project instrument to study changes in the lunar exosphere due to exhaust gases from the lander's engines.[155] K. Sivan, tasked senior scientist Prem Shanker Goel to head the Failure Analysis Committee to look into the causes of the failure.[156]

Both ISRO and NASA attempted to communicate with the lander for about two weeks before the lunar night set in,[113][157] while NASA's LRO flew over on 17 September 2019 and acquired some images of the intended landing zone.[112] However, the region was near dusk, causing poor lighting for optical imaging.[158][159] NASA's LRO images, showing no sight of the lander, were released on 26 September 2019.[143] The LRO flew over again on 14 October 2019 under more favourable lighting conditions,[160][161] but was unable to locate it.[162][163] The LRO performed a third flyover on 10 November 2019.[162]

On 16 November 2019, the Failure Analysis Committee released its report to the Space Commission, concluding that the crash was caused by a software glitch.[50] Phase One of descent the Rough Braking Phase from an altitude of 30 km to 7.4 km above the Moon's surface went as intended with velocity being reduced from 1683 m/s to 146 m/s. Anomalous deviation in performance began 693.8 seconds into powered descent after the end of first phase and with the beginning of Absolute Navigation Phase (also known as Camera Coasting Phase) where lander's orientation is deliberately kept fixed. It was found that lander's main engines had slightly higher thrust of 422 N (95 lbf) than nominal at 360 N (81 lbf),[164] so during this phase lander slowed down more than it should have. The thrust control algorithm was configured to apply corrections towards the end of the phase and not instantaneously allowing large navigation errors to be accumulated. After end of camera coasting phase, rate of applying corrections was limited due to builtin safety constraints such as maximum rate at which attitude can change. Other contributing issues were, coarse throttling of main engines,[73] polarity related software error,[164] wrong computation of remaining time of flight by onboard algorithm and very rigid requirement to land inside the planned 500×500 meter landing site regardless of non-nominal flight status. Subsequently, Vikram lander ended up increasing its horizontal velocity (48 m/s) to reach landing site while descending at high rate (50 m/s) causing Vikram to land hard,[165][166][167][168] though it managed to impact relatively near the intended landing site.[169] The complete official report has not been made public.[170][171][172]

Vikram's impact site was located at 70°52′52″S 22°47′02″E / 70.8810°S 22.7840°E / -70.8810; 22.7840 by the LROC team after receiving helpful input from Shanmuga Subramanian, a volunteer from Chennai, Tamil Nadu, who located debris from the spacecraft in pictures released by NASA.[173][174] While initially estimated to be within 500 m (1,600 ft) of the intended landing site, best-guess estimates from satellite imagery indicate initial impact about 600 m away.[175] The spacecraft shattered upon impact,[176] with debris scattered over almost two dozen locations in an area spanning kilometres.[174] The crash site was later named Tiranga Point after the Chandrayaan-3 landing.[177]

The orbiter part of the mission, with eight scientific instruments, remains operational, and will continue its seven-year mission to study the Moon.[148]

Timeline of operations [178][179]
Phase Date Event Detail Result References
Apogee /
Aposelene 		Perigee /
Periselene
Geocentric phase 22 July 2019, 09:13:12 UTC Launch Burn time: 16 min 14 sec 45,475 km (28,257 mi) 169.7 km (105.4 mi) [43]
24 July 2019, 09:22 UTC 1st orbit-raising manoeuvre Burn time: 48 seconds 45,163 km (28,063 mi) 230 km (140 mi) [180]
25 July 2019, 19:38 UTC 2nd orbit-raising manoeuvre Burn time: 883 seconds 54,829 km (34,069 mi) 251 km (156 mi) [181]
29 July 2019, 09:42 UTC 3rd orbit-raising manoeuvre Burn time: 989 seconds 71,792 km (44,609 mi) 276 km (171.5 mi) [182]
2 August 2019, 09:57 UTC 4th orbit-raising manoeuvre Burn time: 646 seconds 89,472 km (55,595 mi) 277 km (172 mi) [183]
6 August 2019, 09:34 UTC 5th orbit-raising manoeuvre Burn time: 1041 seconds 142,975 km (88,841 mi) 276 km (171 mi) [132]
13 August 2019, 20:51 UTC Trans-lunar injection Burn time: 1203 seconds
—
—
 [133]
Selenocentric phase 20 August 2019, 03:32 UTC Lunar orbit insertion
1st lunar bound manoeuvre 		Burn time: 1738 seconds 18,072 km (11,229 mi) 114 km (71 mi) [136]
21 August 2019, 07:20 UTC 2nd lunar bound manoeuvre Burn time: 1228 seconds 4,412 km (2,741 mi) 118 km (73 mi) [137]
28 August 2019, 03:34 UTC 3rd lunar bound manoeuvre Burn time: 1190 seconds 1,412 km (877 mi) 179 km (111 mi) [138]
30 August 2019, 12:48 UTC 4th lunar bound manoeuvre Burn time: 1155 seconds 164 km (102 mi) 124 km (77 mi) [139]
1 September 2019, 12:51 UTC 5th lunar bound manoeuvre Burn time: 52 seconds 127 km (79 mi) 119 km (74 mi) [140]
Vikram lunar landing 2 September 2019, 07:45 UTC Vikram separation
—
 127 km (79 mi) 119 km (74 mi) [141]
3 September 2019 3:20 UTC 1st deorbit burn Burn time: 4 seconds 128 km (80 mi) 104 km (65 mi) [184]
3 September 2019, 22:12 UTC 2nd deorbit burn Burn time: 9 seconds 101 kilometres (63 mi) 35 km (22 mi) [185]
6 September 2019, 20:08 UTC Powered descent Burn time: 15 minutes Landing (planned) Landing (planned)
6 September 2019, 20:23 UTC Vikram landing Trajectory deviation started at 2.1 km altitude, telemetry was lost seconds before touchdown.[45][149] Lost upon crash landing.
7 September 2019, 00:00 UTC−01:00 UTC (planned) Pragyan rover deployment Lander failure, rover was not deployed.
—
—
 [186][187][188]

Telemetry, tracking, and command (TT&C)

[edit]

During various phases of launch and spacecraft operations of Chandrayaan-2 mission, the TT&C support was provided by ISRO Telemetry, Tracking and Command Network (ISTRAC), Indian Deep Space Network (IDSN), NASA Deep Space Network and National Institute for Space Research's (INPE) ground stations located in Alcântara and Cuiabá.[189][190]

Aftermath

[edit]

There was an outpouring of support for ISRO from various quarters in the aftermath of the crash landing of its lunar lander. However, prominent Indian news media also criticized ISRO's lack of transparency regarding the crash of the lander and its analysis of the crash.[191][154] Indian media also noted that unlike ISRO's previous record, the report of the Failure Analysis Committee was not made public[51] and RTI queries seeking it were denied by ISRO citing section 8(1) of the RTI Act.[192] ISRO's lack of consistency regarding the explanation around the rover's crashing was criticized, with the organization providing no proof of its own positions until the efforts of NASA and a Chennai based volunteer located the crash site on the lunar surface.[193] In the wake of the events surrounding Chandrayaan-2, former ISRO employees criticized unverified statements from chairman K Sivan and what they claimed is the top-down leadership and working culture of the organization.[194][195][196] S Somanath who succeeded K Sivan as ISRO Chairman also expressed his dissatisfaction at the lack of transparency around landing failure, and misleading representation of it.[197][198][199]

Scientists involved in the mission

[edit]
A view of Mission Operations Complex (MOX-1), ISTRAC[200] prior to the fourth Earth-bound burn[183]

Key scientists and engineers involved in the development of Chandrayaan-2 include:[201][202][203]

Reattempt

[edit]
Main article: Chandrayaan-3

In November 2019, ISRO officials stated that a new lunar lander mission was being studied and prepared. It was launched on 14 July 2023;[208] with the designation Chandrayaan-3, which was a second attempt to demonstrate the landing capabilities needed for the Lunar Polar Exploration Mission proposed in partnership with Japan for 2025.[209][210] The new mission was designed with a detachable propulsion module, also behaving like a communications relay satellite,[211] a lander and a rover,[212][213][214] but with no orbiter. S. Somanath, the VSSC director, announced that there would be more follow-up missions in the Chandrayaan programme.[168][215]

In December 2019, it was reported that ISRO requested the initial funding of the project, amounting to ₹75 crore (US$9.0 million), of which ₹60 crore (US$7.2 million) is intended for machinery, equipment and other capital expenditure, while the remaining ₹15 crore (US$1.8 million) was sought under a revenue expenditure allowance.[216] K. Sivan stated that its cost would be around ₹615 crore (equivalent to ₹724 crore or US$87 million in 2023).[217] It performed a soft landing on the Moon on 23 August 2023.[218]

See also

[edit]

References

[edit]
  1. ^ a b c d "Chandrayaan-2 Latest Update". Indian Space Research Organisation. 7 September 2019. Archived from the original on 8 September 2019. Retrieved 7 September 2019.
  2. ^ a b c d e Nair, Avinash (31 May 2015). "ISRO to deliver "eyes and ears" of Chandrayaan-2 by 2015-end". The Indian Express. Archived from the original on 15 February 2018. Retrieved 7 August 2016.
  3. ^ a b c d e f g h i "Launch Kit of GSLV Mk III M1 Chandrayaan-2" (PDF). Indian Space Research Organisation. 19 July 2019. Archived (PDF) from the original on 19 July 2019. Retrieved 21 July 2019.
  4. ^ a b c d e f g "Chandrayaan-2 to Be Launched in January 2019, Says ISRO Chief". NDTV. 29 August 2018. Archived from the original on 29 August 2018. Retrieved 29 August 2018.
  5. ^ a b c d e f g "ISRO to send first Indian into Space by 2022 as announced by PM, says Dr Jitendra Singh" (Press release). Department of Space. 28 August 2018. Archived from the original on 28 August 2018. Retrieved 29 August 2018.
  6. ^ a b c d e "Chandrayaan-2: All you need to know about India's 2nd Moon mission". The Times of India. 21 July 2019. Archived from the original on 14 July 2019. Retrieved 22 July 2019.
  7. ^ "Chandrayaan-2". Indian Space Research Organisation. Archived from the original on 29 July 2019. Retrieved 20 June 2019.
  8. ^ a b c d e "Launch kit at a glance". Indian Space Research Organisation. Archived from the original on 23 July 2019. Retrieved 23 July 2019.
  9. ^ a b c "Chandrayan-2 Launch Rescheduled on 22 July 2019, AT 14:43 HRS". Indian Space Research Organisation. 18 July 2019. Archived from the original on 30 August 2019. Retrieved 18 July 2019.
  10. ^ Singh, Surendra (5 August 2018). "Chandrayaan-2 launch put off: India, Israel in lunar race for 4th position". The Times of India. Archived from the original on 19 August 2018. Retrieved 15 August 2018.
  11. ^ a b Shenoy, Jaideep (28 February 2016). "ISRO chief signals India's readiness for Chandrayaan II mission". The Times of India. Archived from the original on 20 July 2019. Retrieved 7 August 2016.
  12. ^ Ratcliffe, Rebecca (22 July 2019). "India's Chandrayaan-2 moon mission lifts off a week after aborted launch". The Guardian. Archived from the original on 22 July 2019. Retrieved 23 July 2019.
  13. ^ a b "GSLV-Mk III – M1 / Chandrayaan-2 Mission". Indian Space Research Organisation. Archived from the original on 12 September 2019. Retrieved 21 July 2019.
  14. ^ a b c d e Kiran Kumar, Aluru Seelin (August 2015). Chandrayaan-2 – India's Second Moon Mission. youtube.com. Inter-University Centre for Astronomy and Astrophysics. Retrieved 7 August 2016.
  15. ^ "ISRO aims for Chandrayaan-2 landing at 1.55 AM on September 7, says Dr K. Sivan" (Press release). Delhi. Press Information Bureau. Archived from the original on 20 August 2019. Retrieved 24 August 2019.
  16. ^ Madhumathi, D. S. (9 June 2019). "ISRO gears up for Chandrayaan-2 mission". The Hindu. Archived from the original on 19 June 2019. Retrieved 10 June 2019.
  17. ^ Chand, Manish (12 November 2007). "India, Russia to expand n-cooperation, defer Kudankulam deal". Nerve. Archived from the original on 13 January 2014. Retrieved 12 January 2015.
  18. ^ a b "Unstarred Question No:1402 in Lok Sabha about Chandrayaan-2" (PDF). 14 August 2013. Archived from the original (PDF) on 18 August 2023.
  19. ^ Sunderarajan, P. (19 September 2008). "Cabinet clears Chandrayaan-2". The Hindu. Archived from the original on 20 July 2021. Retrieved 23 October 2008.
  20. ^ "ISRO completes Chandrayaan-2 design". Domain-b.com. 17 August 2009. Archived from the original on 8 June 2019. Retrieved 20 August 2009.
  21. ^ a b c d e f g h i j "Payloads for Chandrayaan-2 Mission Finalised" (Press release). Indian Space Research Organisation. 30 August 2010. Archived from the original on 13 May 2019. Retrieved 4 January 2010.
  22. ^ a b c Ramachandran, R. (22 January 2013). "Chandrayaan-2: India to go it alone". The Hindu. Archived from the original on 1 August 2017. Retrieved 21 January 2013.
  23. ^ a b Laxman, Srinivas (6 February 2012). "India's Chandrayaan-2 Moon Mission Likely Delayed After Russian Probe Failure". Asian Scientist. Archived from the original on 8 June 2019. Retrieved 5 April 2012.
  24. ^ "India's next moon mission depends on Russia: ISRO chief". NDTV. 9 September 2012. Archived from the original on 8 June 2019. Retrieved 2 April 2016.
  25. ^ Jayaraman, K. S. (15 August 2013). "India Drops Russia from Chandrayaan-2 Lunar Mission". SpaceNews.
  26. ^ "Chandrayaan-2" (Press release). Department of Space. 14 August 2013. Archived from the original on 5 August 2019. Retrieved 26 August 2017. Chandrayaan-2 would be a lone mission by India without Russian tie-up.
  27. ^ "How ISRO modified a lunar orbiter into Mars orbiter Mangalyaan, India's "Moon Man" recalls". Zee News. 25 October 2020. Archived from the original on 26 October 2020. Retrieved 25 October 2020.
  28. ^ Clark, Stephen (15 August 2018). "Launch Schedule". Spaceflight Now. Archived from the original on 16 August 2018.
  29. ^ "Chandrayaan-2 launch postponed to October: ISRO chief". India Times. 23 March 2018. Archived from the original on 11 July 2019. Retrieved 16 August 2018.
  30. ^ a b "Soft-landing challenges keep Chandrayaan-2 grounded". The Times of India. 5 August 2018. ISSN 0971-8257. Archived from the original on 29 December 2021. Retrieved 9 July 2023.
  31. ^ a b c Kumar, Chethan (12 August 2018). "ISRO wants Chandrayaan-2 lander to orbit Moon first". The Times of India. Archived from the original on 23 April 2019. Retrieved 15 August 2018.
  32. ^ "Chandrayaan-2: Several challenges to meet Jan 2019 deadline". The Times of India. 25 September 2018. ISSN 0971-8257. Archived from the original on 16 April 2021. Retrieved 9 July 2023.
  33. ^ "With eye on lunar mission, ISRO to test high-thrust Vikas engine". The New Indian Express. 28 March 2018. Archived from the original on 4 April 2023. Retrieved 9 July 2023.
  34. ^ "ISRO chief on a mission to cut expenses on launches". The Hindu. 30 January 2018. ISSN 0971-751X. Archived from the original on 9 November 2020. Retrieved 10 July 2023.
  35. ^ "ISRO faces costly proposition over recall of GSAT-11". The New Indian Express. August 2018. Archived from the original on 6 April 2022. Retrieved 10 July 2023.
  36. ^ "What caused delay in ISRO's Chandrayaan-2 launch". The Week. Archived from the original on 13 August 2022. Retrieved 9 July 2023.
  37. ^ "ISRO to launch PSLVC-46 followed by PSLVC-47, Chandrayaan-2 in May: K. Sivan". Asian News International. 1 April 2019. Archived from the original on 1 April 2019. Retrieved 1 April 2019.
  38. ^ "India's Moon Lander Damaged During Test, Chandrayaan 2 Launch Put on Hold". The Wire. 4 April 2019. Archived from the original on 7 April 2019. Retrieved 7 April 2019.
  39. ^ "Vikram hurt during practice, puts Chandrayaan-2 on bench". The Times of India. 4 April 2019. ISSN 0971-8257. Archived from the original on 10 April 2023. Retrieved 9 July 2023.
  40. ^ a b "Press release on Chandrayaan-2, ISRO". Indian Space Research Organisation. Archived from the original on 25 July 2019. Retrieved 1 May 2019.
  41. ^ a b "Chandrayaan 2 Moon Mission Launch Aborted After Technical Snag: 10 Points". NDTV. Archived from the original on 15 July 2019. Retrieved 15 July 2019.
  42. ^ a b "ISRO pinpoints GSLV-MkIII leak to 'nipple joint' of cryo engine". The Times of India. 17 July 2019. Archived from the original on 22 July 2019. Retrieved 23 July 2019.
  43. ^ a b c d "GSLV MkIII-M1 Successfully Launches Chandrayaan-2 spacecraft". Indian Space Research Organisation. Archived from the original on 12 December 2019. Retrieved 23 July 2019.
  44. ^ "Extra brake thrust may have sent Vikram out of control in home stretch". The Times of India. 8 September 2019. Archived from the original on 8 September 2019. Retrieved 8 September 2019.
  45. ^ a b c Neel V. Patel (6 September 2019). "India's Chandrayaan-2 lander likely crashed into the Moon's surface". MIT Technology Review. Archived from the original on 6 September 2019. Retrieved 7 September 2019.
  46. ^ a b Chang, Kenneth (10 September 2019). "Did India's Chandrayaan-2 Moon Lander Survive? The Chances Are Slim". The New York Times. Archived from the original on 11 September 2019. Retrieved 11 September 2019.
  47. ^ a b c India's Moon Mission Continues Despite Apparent Lander Crash. Archived 9 September 2019 at the Wayback Machine Mike Wall, space.com, 7 September 2019, Quote: "India's Moon Mission Continues Despite Apparent Lander Crash".
  48. ^ a b "India's Vikram Spacecraft Apparently Crash – Lands on Moon". planetary.org. Archived from the original on 10 September 2019. Retrieved 7 September 2019.
  49. ^ a b "Vikram lander located on lunar surface, wasn't a soft landing: ISRO". The Times of India. 8 September 2019. Archived from the original on 12 November 2020. Retrieved 8 September 2019.
  50. ^ a b How did Chandrayaan-2 fail? ISRO finally has the answer Archived 19 February 2021 at the Wayback Machine Mahesh Guptan, The Week 16 November 2019
  51. ^ a b "Chandrayaan-2: Three months on, ISRO yet to make public Vikram lander failure report details". The Indian Express. 19 December 2019. Archived from the original on 7 January 2020. Retrieved 17 January 2020. "This is unlike the ISRO's previous record. For instance, after the failure of an operational fourth flight of the heavy lift GSLV rocket — the GSLV-F02 mission — on 10 July 2006, a 15-member FAC was tasked with providing a report in a month. After the report was submitted to the government, ISRO made the details public on 6 September 2006, on its website. In 2010, when GSLV D3, a developmental flight and the fifth heavy lift GSLV rocket, failed after launch on 15 April 2010, an FAC report was submitted with the government on 24 May 2010. Details of the report were made public on 9 July 2010. The same year, when GSLV F06, an operational sixth flight for GSLV rocket, failed on 25 December 2011, ISRO went public on 31 December 2011, with findings of an analysis of failure done by a preliminary FAC comprising space experts".
  52. ^ "Chandrayaan-2 Orbiter (CH2O) performs an evasive manoeuvre to mitigate a critically close approach with LRO – ISRO". www.isro.gov.in. Archived from the original on 15 November 2021. Retrieved 15 November 2021.
  53. ^ "Chandrayaan-2 CHANDRYN2". NASA. Archived from the original on 29 July 2019. Retrieved 3 July 2019.
  54. ^ Rathinavel, T.; Singh, Jitendra (24 November 2016). "Question No. 1084: Deployment of Rover on Lunar Surface" (PDF). Rajya Sabha. Archived (PDF) from the original on 2 August 2017. Retrieved 2 August 2017.
  55. ^ Banerji, Abigail (13 July 2019). "Chandrayaan 2: Everything you need to know about the orbiter's mission and design". First Post. Archived from the original on 19 July 2019. Retrieved 14 July 2019.
  56. ^ Monier Monier-Williams, A Sanskrit-English Dictionary (1899): candra: "[...] m. the moon (also personified as a deity Mn. &c)" yāna: "[...] n. a vehicle of any kind, carriage, wagon, vessel, ship, [...]"
  57. ^ "Chandrayaan-2 FAQ". Archived from the original on 29 June 2019. Retrieved 24 August 2019. The name Chandrayaan means "Chandra- Moon, Yaan-vehicle", –in Indian languages (Sanskrit and Hindi), – the lunar spacecraft.
  58. ^ a b Ramesh, Sandhya (12 June 2019). "Why Chandrayaan-2 is ISRO's "most complex mission" so far". The Print. Archived from the original on 11 July 2019. Retrieved 12 June 2019.
  59. ^ Singh, Surendra (20 February 2018). "Chandrayaan-2 mission cheaper than Hollywood film Interstellar". The Times of India. Archived from the original on 26 July 2019. Retrieved 3 March 2018.
  60. ^ "Department of Space presentation on 18 Jan 2019" (PDF). Department of Space. 18 January 2019. Archived (PDF) from the original on 30 January 2019. Retrieved 30 January 2019.
  61. ^ a b c "Annual Report 2014–2015" (PDF). Indian Space Research Organisation. December 2014. p. 82. Archived (PDF) from the original on 4 March 2016. Retrieved 7 August 2016.
  62. ^ a b "Chandrayaan-2 to get closer to moon". The Economic Times. 2 September 2010. Archived from the original on 12 August 2011.
  63. ^ a b "Annual Report 2015-2016" (PDF). Indian Space Research Organisation. December 2015. p. 89. Archived from the original (PDF) on 5 July 2016.
  64. ^ "HAL Delivers the Orbiter Craft Module Structure of Chandrayaan-2 to ISRO". Hindustan Aeronautics Limited. 22 June 2015. Archived from the original on 2 September 2018.
  65. ^ a b c Singh, Surendra (7 September 2019). "Orbiter will have a lifespan of 7.5 years, it's possible to find Vikram Lander from orbiter: ISRO chief". The Times of India. Archived from the original on 8 September 2019. Retrieved 7 September 2019.
  66. ^ a b "First set of beautiful images of the Earth captured by Chandrayaan-2 Vikram Lander". Archived from the original on 6 August 2019. Retrieved 25 August 2019.
  67. ^ Wilson, Horace Hayman (1832). A dictionary in Sanscrit and English. Calcutta: Education Press. p. 760. Archived from the original on 9 February 2019. Retrieved 7 February 2019.
  68. ^ Kumar, Chethan (12 August 2018). "Chandrayaan-2 Lander to be named "Vikram" after Sarabhai". The Times of India. Archived from the original on 13 August 2018. Retrieved 15 August 2018.
  69. ^ "Paper information (56421) — IAF". iafastro.directory. Archived from the original on 22 October 2020. Retrieved 20 October 2020.
  70. ^ "ISRO developing vehicle to launch small satellites". Frontline. Retrieved 29 August 2018. Making a throttleable engine of 3 kilonewtons or 4 kilonewtons is a totally new development for us. But we wanted to make use of available technologies. We have a LAM [liquid apogee motor] with a 400 newtons thruster, & we have been using it on our satellites. We enhanced it to 800 newtons. It was not a major, new design change.
  71. ^ Mondal, Chinmoy; Chakrabarti, Subrata; Venkittaraman, D.; Manimaran, A. (2015). Development of a Proportional Flow Control Valve for the 800 N Engine Test. 9th National Symposium and Exhibition on Aerospace and Related Mechanisms, January 2015, Bengaluru, India. Archived from the original on 20 July 2021. Retrieved 29 August 2018.
  72. ^ "Chandrayaan-2: The second Indian mission to the Moon" (PDF). hou.usra.edu. 1 February 2020. Archived (PDF) from the original on 19 June 2020. Retrieved 1 February 2020.
  73. ^ a b Dr P V Venkitakrishnan, Ad Ingenium, Lecture 4 (Video). 5 November 2020. Event occurs at 1 hour 21 minutes 48 seconds.
  74. ^ "Chandrayaan-2: First step towards Indians setting foot on moon in near future". The New Indian Express. 8 July 2019. Archived from the original on 8 July 2019. Retrieved 8 July 2019. As solar energy powers the system, a place with good visibility and area of communication was needed. Also, the place where the landing takes place should not have many boulders and craters. The slope for landing should be less than 12 degrees. The South pole has a near-flat surface, with good visibility and sunlight available from the convenience point of view.
  75. ^ Subramanian, T. S. (9 July 2019). "Chandrayaan 2: Giant leap for ISRO". Frontline. Archived from the original on 9 April 2020. Retrieved 9 July 2019.
  76. ^ "How ISRO Plans To Pull Off An Unprecedented Landing on Moon's South Pole". NDTV.com. Archived from the original on 5 September 2019. Retrieved 5 September 2019.
  77. ^ "Space Applications Centre, Annual Report 2016–17" (PDF). SAC.gov.in. p. 35. Archived (PDF) from the original on 2 January 2018. Retrieved 20 July 2019.
  78. ^ "Key payload for Chandrayaan-2 leaves for Bengaluru". The Times of India. Archived from the original on 2 August 2019. Retrieved 20 July 2019.
  79. ^ "SAC Seminar 2016" (PDF). sac.gov.in (in Hindi). 21 July 2017. p. 94. Archived (PDF) from the original on 5 September 2019. Retrieved 5 September 2019.
  80. ^ "Department of Space Annual Report 2016–17" (PDF). Indian Space Research Organisation. Archived (PDF) from the original on 18 March 2017. Retrieved 20 July 2019.
  81. ^ Madhumathi, D. S. (25 October 2016). "ISRO starts landing tests for Chandrayaan-2 mission". The Hindu. Archived from the original on 20 July 2021. Retrieved 28 October 2016.
  82. ^ "ISRO begins flight integration activity for Chandrayaan-2, as scientists tests lander and rover". The Indian Express. 25 October 2017. Archived from the original on 13 December 2017. Retrieved 21 December 2017.
  83. ^ a b "Chandrayaan-2 Spacecraft". Indian Space Research Organisation. Archived from the original on 18 July 2019. Retrieved 24 August 2019. Chandrayaan 2's Rover is a 6-wheeled robotic vehicle named Pragyan, which translates to "wisdom" in Sanskrit.
  84. ^ Wilson, Horace Hayman (1832). A dictionary in Sanscrit and English. Calcutta: Education Press. p. 561. Archived from the original on 9 February 2019. Retrieved 7 February 2019.
  85. ^ Elumalai, V.; Kharge, Mallikarjun (7 February 2019). "Chandrayaan–II" (PDF). pib.nic.in. Archived from the original (PDF) on 7 February 2019. Retrieved 7 February 2019. Lander (Vikram) is undergoing final integration tests. Rover (Pragyan) has completed all tests and waiting for the Vikram readiness to undergo further tests.
  86. ^ "ISRO to Launch Chandrayaan 2 on July 15, Moon Landing by September 7". The Wire. 12 June 2019. Archived from the original on 13 June 2019. Retrieved 12 June 2019.
  87. ^ Singh, Surendra (10 May 2019). "Chandrayaan-2 will carry 14 payloads to moon, no foreign module this time". The Times of India. TNN. Archived from the original on 10 May 2019. Retrieved 11 May 2019.
  88. ^ Subhalakshmi, K.; Basavaraj, B.; Selvaraj, P.; Laha, J. (22 December 2010). "Design of Miniature Space Grade Navigation Camera for Lunar Mission". 2010 International Symposium on Electronic System Design. pp. 169–174. doi:10.1109/ISED.2010.40. ISBN 978-1-4244-8979-4. S2CID 25978793.
  89. ^ "With robot hands, IIT-K profs bring joy to paralytics". The Times of India. 2019. Archived from the original on 20 July 2019. Retrieved 10 July 2019.
  90. ^ Annadurai, Mylswami; Nagesh, G.; Vanitha, Muthayaa (28 June 2017). ""Chandrayaan-2: Lunar Orbiter and Lander Mission", 10th IAA Symposium on The Future of Space Exploration: Towards the Moon Village and Beyond, Torin, Italy". International Academy of Astronautics. Archived from the original on 30 August 2017. Retrieved 14 June 2019. Mobility of the Rover in the unknown lunar terrain is accomplished by a Rocker bogie suspension system driven by six wheels. Brushless DC motors are used to drive the wheels to move along the desired path and steering is accomplished by differential speed of the wheels. The wheels are designed after extensive modelling of the wheel-soil interaction, considering the lunar soil properties, sinkage and slippage results from a single wheel test bed. The rover mobility has been tested in the lunar test facility wherein the soil simulant, terrain and the gravity of moon are simulated. The limitations w.r.t slope, obstacles, pits in view of slippage/sinkage have been experimentally verified with the analysis results.
  91. ^ "Dr M. Annadurai, project director, Chandrayaan-1: "Chandrayaan-2 logical extension of what we did in first mission"". The Indian Express. 29 June 2019. Archived from the original on 29 June 2019. Retrieved 30 June 2019.
  92. ^ Payyappilly, Baiju; Muthusamy, Sankaran (17 January 2018). "Design framework of a configurable electrical power system for lunar rover". 2017 4th International Conference on Power, Control & Embedded Systems (ICPCES). pp. 1–6. doi:10.1109/ICPCES.2017.8117660. ISBN 978-1-5090-4426-9. S2CID 38638820. Archived from the original on 20 July 2021. Retrieved 13 July 2019.
  93. ^ "Ashoka Chakra, ISRO Logo, Flag: Chandrayaan-2 Set to Engrave India's Name on Moon for Centuries". News18. Archived from the original on 4 September 2019. Retrieved 4 September 2019.
  94. ^ Curtain Raiser video (Hindi) (in Hindi). Indian Space Research Organisation. Event occurs at 1 minute 55 seconds. Archived from the original on 14 July 2019. Retrieved 4 September 2019.
  95. ^ a b c Bagla, Pallava (31 January 2018). "India plans tricky and unprecedented landing near moon's south pole". Science Mag. Archived from the original on 22 July 2019. Retrieved 8 March 2018.
  96. ^ a b c d e f "Chandrayaan-2 Payloads". Indian Space Research Organisation. 12 June 2019. Archived from the original on 13 July 2019. Retrieved 13 July 2019.
  97. ^ Beary, Habib (4 February 2010). "NASA and ESA to partner for Chandrayaan-2". Sakal Times. Archived from the original on 15 July 2011. Retrieved 22 February 2010.{{cite news}}: CS1 maint: unfit URL (link)
  98. ^ Laxman, Srinivas (5 September 2010). ""We're launching Chandrayaan-2 for a total coverage of the moon"". The Times of India. Archived from the original on 19 May 2017. Retrieved 2 April 2016.
  99. ^ a b Bartels, Meghan (24 March 2019). "How NASA Scrambled to Add Science Experiments to Israeli, Indian Moon Probes". space.com. Archived from the original on 25 March 2019. Retrieved 25 March 2019.
  100. ^ a b c Gohd, Chelsea (26 July 2019). "50 Years After Apollo, India Is Carrying a NASA Laser Reflector to the Moon (And It's Only the Start)". space.com. Archived from the original on 26 July 2019. Retrieved 26 July 2019.
  101. ^ "Implementing arrangement between India and United States of America for cooperation on the Chandrayaan mission-2" (PDF). Ministry of External Affairs. 11 February 2019. Archived (PDF) from the original on 30 July 2019. Retrieved 30 July 2019.
  102. ^ "Chandrayaan-2 Large Area Soft X-ray Spectrometer" (PDF). Current Science. 24 January 2020. Archived from the original (PDF) on 27 July 2020. Retrieved 24 January 2020.
  103. ^ "Solar X-ray Monitor onboard Chandrayaan-2 Orbiter" (PDF). Current Science. 10 January 2020. Archived from the original (PDF) on 14 January 2020. Retrieved 14 January 2020.
  104. ^ "L- and S-band Polarimetric Synthetic Aperture Radar on Chandrayaan-2 mission" (PDF). Current Science. 24 January 2020. Archived from the original (PDF) on 27 July 2020. Retrieved 24 January 2020.
  105. ^ "Imaging Infrared Spectrometer onboard Chandrayaan-2 Orbiter" (PDF). Current Science. 10 February 2020. Archived from the original (PDF) on 7 February 2020. Retrieved 7 February 2020.
  106. ^ "Lynred IR detector onboard Chandrayaan-2 expedition to Moon's South Pole" (PDF). lynred.com. Archived (PDF) from the original on 26 September 2019.
  107. ^ "CHANDRAYAAN-2 spectrometer for IIRS". AMOS. 15 November 2018. Archived from the original on 26 September 2019. Retrieved 26 September 2019.
  108. ^ "CHandra's Atmospheric Composition Explorer-2 onboard Chandrayaan-2 to study the lunar neutral exosphere" (PDF). Current Science. 24 January 2020. Archived from the original (PDF) on 27 July 2020. Retrieved 24 January 2020.
  109. ^ "Terrain Mapping Camera-2 onboard Chandrayaan-2 Orbiter" (PDF). Current Science. 25 February 2020. Archived from the original (PDF) on 22 February 2020. Retrieved 22 February 2020.
  110. ^ "Dual Frequency Radio Science experiment onboard Chandrayaan-2: a radio occultation technique to study temporal and spatial variations in the surface-bound ionosphere of the Moon" (PDF). Current Science. 24 January 2020. Archived from the original (PDF) on 27 July 2020. Retrieved 24 January 2020.
  111. ^ Chowdhury AR, Saxena M, Kumar A, Joshi SR, Amitabh, Dagar A, Mittal M, Kirkire S, Desai J, Shah D, Karelia JC, Kumar A, Jha K, Das P, Bhagat HV, Sharma J, Ghonia DN, Desai M, Bansal G, Gupta A (2020). "Orbiter High Resolution Camera onboard Chandrayaan-2 Orbiter" (PDF). Current Science. 118 (4): 560–565. doi:10.18520/cs/v118/i4/560-565. S2CID 211254790. Archived from the original (PDF) on 27 July 2020.
  112. ^ a b Clark, Stephen (12 September 2019). "NASA lunar orbiter to image Chandrayaan-2 landing site". Spaceflight Now. Archived from the original on 13 September 2019. Retrieved 12 September 2019.
  113. ^ a b "Chandrayaan-2 latest update". Indian Space Research Organisation. Archived from the original on 4 September 2019. Retrieved 7 September 2019.
  114. ^ "Instrument for Lunar Seismic Activity Studies on Chandrayaan-2 Lander" (PDF). Current Science. 10 February 2020. Archived from the original (PDF) on 7 February 2020. Retrieved 7 February 2020.
  115. ^ Mallikarjun, Y. (29 May 2013). "India plans to send seismometer to study moonquakes". The Hindu. Archived from the original on 10 February 2014. Retrieved 1 June 2013.
  116. ^ Mishra, Sanjeev (September 2019). "PRL News- The Spectrum" (PDF). Physical Research Laboratory. Archived (PDF) from the original on 26 September 2019. Retrieved 7 December 2021.
  117. ^ "Lunar near surface plasma environment from Chandrayaan-2 Lander platform: RAMBHA-LP payload" (PDF). Current Science. 10 February 2020. Archived (PDF) from the original on 7 February 2020. Retrieved 7 February 2020.
  118. ^ India Heads to the Moon With Chandrayaan-2 Archived 23 July 2019 at the Wayback Machine David Dickinson, Sky & Telescope, 22 July 2019, Quote: "Vikram carries a seismometer, thermal probe, and an instrument to measure variation and density of lunar surface plasma, along with a laser retro-reflector supplied by NASA's Goddard Spaceflight Center".
  119. ^ "Laser Induced Breakdown Spectroscope on Chandrayaan-2 Rover: a miniaturized mid-UV to visible active spectrometer for lunar surface chemistry studies" (PDF). Current Science. 25 February 2020. Archived from the original (PDF) on 22 February 2020. Retrieved 22 February 2020.
  120. ^ "Alpha Particle X-ray Spectrometer onboard Chandrayaan-2 Rover" (PDF). Current Science. 10 January 2020. Archived from the original (PDF) on 14 January 2020. Retrieved 14 January 2020.
  121. ^ "India chooses Russian Cm-244 sources for flights to the Moon". isotop.ru. Archived from the original on 26 September 2019. Retrieved 26 September 2019.
  122. ^ "PRL News – The Spectrum, September 2019" (PDF). prl.res.in. Archived (PDF) from the original on 26 September 2019.
  123. ^ "Chandrayaan-2 Orbiter Maps An 'Abundance of Sodium' On the Moon's Surface for the First Time Ever; Here's What It Means". The Weather Channel. Retrieved 8 November 2022.
  124. ^ Matta, M.; Smith, S.; Baumgardner, J.; Wilson, J.; Martinis, C.; Mendillo, M. (December 2009). "The sodium tail of the Moon". Icarus. 204 (2): 409–417. doi:10.1016/j.icarus.2009.06.017.
  125. ^ Subramanian, T. S. (17 July 2019). "What went wrong with the Chandrayaan-2 launch". Frontline. Archived from the original on 27 July 2020. Retrieved 24 July 2019.
  126. ^ Chandran, Cynthia (23 July 2019). "For VSSC chief, setbacks are part of victory cruise". Deccan Chronicle. Archived from the original on 23 July 2019. Retrieved 24 July 2019.
  127. ^ Kumar, Chethan (23 July 2019). "Chandrayaan-2 will only have 4 operations around Earth". The Times of India. Archived from the original on 24 July 2019. Retrieved 24 July 2019.
  128. ^ "Live coverage: India's Chandrayaan-2 moon mission blasts off". Spaceflight Now. Archived from the original on 22 July 2019. Retrieved 24 July 2019.
  129. ^ Kumar, Chethan (29 July 2019). "Chandrayaan-2 healthy after another manoeuvre". The Times of India. Archived from the original on 30 July 2019. Retrieved 29 July 2019.
  130. ^ Hartley, Anna (23 July 2019). "Strange object in the night sky was probably a rocket heading to the Moon: astronomer". ABC News. Archived from the original on 27 July 2019. Retrieved 27 July 2019.
  131. ^ Acharya, Mosiqi (24 July 2019). "Was the mysterious bright spot in Australian skies Chandrayaan-2, India's mission to Moon?". SBS Hindi. Archived from the original on 27 July 2019. Retrieved 7 September 2019.
  132. ^ a b "Chandrayaan-2: Fifth Earth bound maneuver". Indian Space Research Organisation. Archived from the original on 6 August 2019. Retrieved 6 August 2019.
  133. ^ a b "Chandrayaan-2 Successfully enters Lunar Transfer Trajectory". Indian Space Research Organisation. Archived from the original on 13 August 2019. Retrieved 14 August 2019.
  134. ^ "Here's Why Chandrayaan-2 Will Take 48 Days to Reach the Moon". The Quint. 9 August 2019. Archived from the original on 25 August 2019. Retrieved 25 August 2019.
  135. ^ Kottasová, Ivana; Gupta, Swati (20 August 2019). "India's Chandrayaan-2 moon mission enters lunar orbit". CNN. Archived from the original on 5 September 2019. Retrieved 6 September 2019.
  136. ^ a b "Chandrayaan-2: Lunar Orbit Insertion". Indian Space Research Organisation. Archived from the original on 20 August 2019. Retrieved 20 August 2019.
  137. ^ a b "Chandrayaan-2: Second Lunar Orbit Maneuver". Indian Space Research Organisation. Archived from the original on 21 August 2019. Retrieved 21 August 2019.
  138. ^ a b "Chandrayaan-2: Third Lunar Orbit Maneuver". Indian Space Research Organisation. Archived from the original on 28 August 2019. Retrieved 28 August 2019.
  139. ^ a b "Chandrayaan-2: Fourth Lunar Orbit Maneuver". Indian Space Research Organisation. Archived from the original on 30 August 2019. Retrieved 30 August 2019.
  140. ^ a b "Chandrayaan-2: Fifth Lunar Orbit Maneuver". Indian Space Research Organisation. Archived from the original on 3 September 2019. Retrieved 1 September 2019.
  141. ^ a b "Chandrayaan-2: Vikram Lander successfully separates from Orbiter". Indian Space Research Organisation. Archived from the original on 3 September 2019. Retrieved 2 September 2019.
  142. ^ a b Amitabh, S.; Srinivasan, T. P.; Suresh, K. (2018). Potential Landing Sites for Chandrayaan-2 Lander in Southern Hemisphere of Moon (PDF). 49th Lunar and Planetary Science Conference 19–23 March 2018 The Woodlands, Texas. Bibcode:2018LPI....49.1975A. Archived from the original (PDF) on 22 August 2018.
  143. ^ a b Obscured in the Lunar Highlands? Archived 27 September 2019 at the Wayback Machine Karl Hille, NASA LRO Mission. 26 September 2019 Public Domain This article incorporates text from this source, which is in the public domain.
  144. ^ Srishti Choudhary (14 July 2019). "Chandrayaan-2: How "Lander Vikram" will touchdown on the moon?". Live Mint. Archived from the original on 19 July 2019. Retrieved 11 August 2019.
  145. ^ Geological Insights into Chandrayaan-2 Landing Site in the Southern High Latitudes of the Moon Archived 19 June 2020 at the Wayback Machine Rishitosh K. Sinha, Vijayan Sivaprahasam, Megha Bhatt, Harish Nandal, Nandita Kumari, Neeraj Srivastava, Indhu Varatharajan, Dwijesh Ray, Christian Wöhler, and Anil Bhardwaj. 50th Lunar and Planetary Science Conference 2019 (LPI Contribution No. 2132).
  146. ^ Chandrayaan-2: Here's everything about ISRO Moon-landing its Vikram lander Archived 11 September 2019 at the Wayback Machine Financial Express Ribu Mishra, 7 September 2019
  147. ^ India Just Found Its Lost Vikram Lander on the Moon, Still No Signal Archived 9 September 2019 at the Wayback Machine Tariq Malik ,space.com 8 September 2019
  148. ^ a b India has Located the Vikram Lander, But it's Still not Communicating With Home Archived 13 September 2019 at the Wayback Machine Matt Williams, Universe Today 11 September 2019
  149. ^ a b Frozen screens tell story: Chandrayaan-2's Vikram Lander fell silent 335 m from Moon Archived 16 September 2019 at the Wayback Machine Johnson T. A., Indian Express 11 September 2019
  150. ^ The speed at which it was travelling didn't give Moon lander a chance: Expert Archived 21 September 2019 at the Wayback Machine India Economic Times 21 September 2019
  151. ^ "Lander Vikram located: K Sivan". aninews.in. Archived from the original on 8 September 2019. Retrieved 8 September 2019.
  152. ^ Schultz, Kai (8 September 2019). "India Says It Has Located Chandrayaan-2 Lander on Moon's Surface". The New York Times. Archived from the original on 8 September 2019. Retrieved 8 September 2019.
  153. ^ "Vikram Lander in a Tilted Position – ISRO". The Hindu Business Line. 9 September 2019. Archived from the original on 20 December 2019. Retrieved 20 December 2019.
  154. ^ a b "ISRO finally admits to Chandrayaan-2's lander Vikram lying on Moon "in pieces"". The New Indian Express. 1 January 2020. Archived from the original on 28 July 2020. Retrieved 29 May 2020. On being persistently asked by the media on Wednesday why ISRO was not being transparent about the fate of the lander as the entire nation was waiting with bated breath for a successful landing, Sivan finally said, "Yes, yes...it is in pieces...!"
  155. ^ Bartels, Meghan (13 September 2019). "U.S. Moon Landing Hopefuls Watch Silent India Lander – and Learn". space.com. Archived from the original on 15 September 2019. Retrieved 14 September 2019.
  156. ^ Raghu Krishnan (9 September 2019). "Hard landing derailed lunar mission, says K Sivan". The Economic Times. Archived from the original on 3 January 2021.
  157. ^ Chandrayaan-2: The Sun has finally set on Vikram lander Archived 22 September 2019 at the Wayback Machine Swathi Moorthy, Money Control 22 September 2019
  158. ^ Search for Vikram Lander: NASA Analysing Images Taken by Lunar Reconnaissance Orbiter Archived 20 September 2019 at the Wayback Machine Indo-Asian News Service 19 September 2019
  159. ^ NASA Moon Orbiter Fails to Spot India's Lunar Lander: Report Archived 20 September 2019 at the Wayback Machine Leonard David, space.com 18 September 2019
  160. ^ Bartels, Meghan (24 October 2019). "A NASA Spacecraft Still Hasn't Spotted India's Ill-Fated Moon Lander". space.com. Archived from the original on 25 October 2019. Retrieved 25 October 2019.
  161. ^ NASA still searching for India's Chandrayaan-2 Vikram moon lander Archived 23 September 2019 at the Wayback Machine Amanda Kooser, CNET 18 September 2019
  162. ^ a b Chandrayaan-2: NASA to Perform a "Rigorous" Search for Vikram Lander Archived 20 October 2019 at the Wayback Machine Indo-Asian News Service 18 October 2019
  163. ^ NASA finds no trace of India's Chandrayaan-2 Vikram lander in latest pics by Moon orbiter Archived 24 October 2019 at the Wayback Machine The Economic Times 24 October 2019
  164. ^ a b IIST Foundation Day & Chandrayaan Utsav. 14 September 2023. Event occurs at 38 min. 36 sec. every engine instead of producing 360 N, it was producing 62 N more.
  165. ^ ISRO Chief explains what went wrong with Chandrayaan-2 and how Chandrayaan-3 will be different!. 10 July 2023.
  166. ^ First Prof. (Dr.) Pradeep Memorial Lecture, IISc Alumni Association. "Chandrayaan-3: ISRO's Moon Exploration" by S Somanath, Chairman, ISRO. 5 August 2023. Event occurs at 37 minute 28 seconds.
  167. ^ "Moon Monday #136: Chandrayaan 3 on its way to Luna as Russia and Japan prep their Moonshot, plus NASA mission updates". Retrieved 10 August 2023.
  168. ^ a b Episode 90 – An update on ISRO's activities with S. Somanath and R. Umamaheshwaran. Event occurs at 30 minute 46 seconds.
  169. ^ "Unstarred Question number: 588". Parliament of India, Lok Sabha. Archived from the original on 20 November 2019. Retrieved 20 November 2019. The first phase of descent was performed nominally from an altitude of 30 km to 7.4 km above the moon surface. The velocity was reduced from 1683 m/s to 146 m/s. During the second phase of descent, the reduction in velocity was more than the designed value. Due to this deviation, the initial conditions at the start of the fine braking phase were beyond the designed parameters. As a result, Vikram hard-landed within 500 m of the designated landing site.
  170. ^ Kumar, Chethan (20 November 2019). "Chandrayaan-2: Extra braking caused Vikram to deviate: Govt in LS". The Times of India. Archived from the original on 21 November 2019. Retrieved 20 November 2019.
  171. ^ "New details emerge about failed lunar landings". SpaceNews. 21 November 2019. Archived from the original on 20 July 2021. Retrieved 21 November 2019.
  172. ^ India Admits Its Moon Lander Crashed, Cites Problem with Braking Thrusters Archived 27 November 2019 at the Wayback Machine Chelsea Gohd, space.com 25 November 2019
  173. ^ Chang, Kenneth (2 December 2019). "NASA Finds India's Vikram Moon Lander Crash Site, With Amateur's Help". The New York Times. Archived from the original on 3 December 2019. Retrieved 3 December 2019.
  174. ^ a b "India's crashed Vikram moon lander spotted on lunar surface". The Guardian. Agence France-Presse. 3 December 2019. Archived from the original on 21 December 2019. Retrieved 17 December 2019.
  175. ^ "Vikram Lander Found". Lunar Reconnaissance Orbiter Camera. Archived from the original on 2 December 2019. Retrieved 2 December 2019. Public Domain This article incorporates text from this source, which is in the public domain.
  176. ^ Chang, Kenneth (6 December 2019). "A Billion Pixels and the Search for India's Crashed Moon Lander". The New York Times. Archived from the original on 7 December 2019. Retrieved 7 December 2019.
  177. ^ Livemint (26 August 2023). "PM Modi names Chandrayaan-3 landing site and crash-landed Chandrayaan-2". mint. Retrieved 26 August 2023.
  178. ^ "Chandrayaan-2 update:Mission Plan of Chandrayaan-2 spacecraft". Indian Space Research Organisation. Archived from the original on 24 July 2019. Retrieved 24 July 2019.
  179. ^ "Live media coverage of the landing of Chandrayaan-2 on lunar surface". Indian Space Research Organisation. Archived from the original on 2 September 2019. Retrieved 2 September 2019.
  180. ^ "Chandrayaan-2: First Earth bound maneuver". Indian Space Research Organisation. Archived from the original on 24 July 2019. Retrieved 24 July 2019.
  181. ^ "Chandrayaan-2: Second Earth bound maneuver". Indian Space Research Organisation. 26 July 2019. Archived from the original on 25 July 2019. Retrieved 26 July 2019.
  182. ^ "Chandrayaan-2: Third Earth bound maneuver". Indian Space Research Organisation. Archived from the original on 29 July 2019. Retrieved 29 July 2019.
  183. ^ a b "Chandrayaan-2: Fourth Earth bound maneuver". Indian Space Research Organisation. Archived from the original on 2 August 2019. Retrieved 2 August 2019.
  184. ^ "Chandrayaan-2: First de-orbiting maneuver". Indian Space Research Organisation. Archived from the original on 3 September 2019. Retrieved 3 September 2019.
  185. ^ "Chandrayaan-2: Second de-orbiting maneuver". Indian Space Research Organisation. Archived from the original on 4 September 2019. Retrieved 3 September 2019.
  186. ^ "#Chandrayaan2 ; Vikram and Pragyan Timeline: #Chandrayaan2Live #Chandrayaan2Landingpic.twitter.com/nZ2u18OXjb". @airnewsalerts (in Hungarian). 6 September 2019. Archived from the original on 11 September 2019. Retrieved 11 September 2019.
  187. ^ "Chandrayaan 2 Landing highlights: PM Narendra Modi says India stands in solidarity with ISRO scientists". First Post. 6 September 2019. Archived from the original on 7 October 2019. Retrieved 11 September 2019.
  188. ^ Sharma, Anand Kumar (November 2019). "Chandrayaan-2 – What Went Wrong with the Lander?". Science Reporter. 56 (11): 20–23. Archived from the original on 23 September 2020. Retrieved 27 August 2020.
  189. ^ "INPE realiza manobras orbitais para missão lunar Chandrayaan-2". inpe.br (in Brazilian Portuguese). Archived from the original on 17 November 2019. Retrieved 24 February 2021.
  190. ^ Singh, Surendra (13 June 2019). "ISRO: Chandrayaan-2 will take NASA-ISRO ties to a new height". The Times of India. Archived from the original on 7 November 2020. Retrieved 24 February 2021.
  191. ^ "ISRO silent on NASA pictures of Vikram". The Hindu. 3 December 2019. Archived from the original on 27 July 2020. Retrieved 28 May 2020. "However, except for sketchy information, ISRO has shied away from sharing its own analysis of the crash".
  192. ^ ""ISRO should be transparent": Ex-Chief as ISRO denies info on Vikram Lander failure". The News Minute. 3 November 2020. Archived from the original on 3 November 2020. Retrieved 3 November 2020.
  193. ^ "ISRO: Time for Change of leadership". Newsroom 24x7. 18 December 2019. Archived from the original on 27 July 2020. Retrieved 28 May 2020. Question that remains to be answered by ISRO is where "the proof for what they have been claiming. Why no photographs or a video of the Lander's undocking from the Lunar Orbiter have been made public till now. Only an objective probe will find answers to the questions regarding Chandrayaan-2 and what led to the Lander's failure. There are also many lapses that should make the citizens of India, who fund ISRO's working, sit up straight
  194. ^ "Chandrayaan-2: Was India's Moon mission actually a success?". BBC News. 30 September 2019. Archived from the original on 17 December 2020. Retrieved 28 May 2020. "Mr Sivan's remarks have been met with criticism from scientists who said it was too early for ISRO to term the mission a success, especially since its most important goal – to land a rover on the Moon's surface that can gather crucial data – remains unrealised".
  195. ^ "Senior ISRO Scientist Criticises Sivan's Approach After Moon Mission Setback". The Wire. 22 September 2019. Archived from the original on 7 December 2019. Retrieved 28 May 2020. "Misra called attention to ISRO's top-down working culture and inadequate leadership, particularly in the face of Chandrayaan-2 having failed to execute its surface mission because the lander crashed on the Moon's surface instead of touching down".
  196. ^ "No ISRO update on Chandrayaan-2 lander but social media goes wild with speculation". The Print. 10 September 2019. Archived from the original on 20 July 2021. Retrieved 29 May 2020. "The chairman also released a statement Friday, saying 90 to 95% of mission objectives have already been met. The statement was met with much criticism due to a lack of transparency on the calculation of these percentages".
  197. ^ "K Sivan tried to prevent my elevation to ISRO chairman's post: Somanath". Onmanorama. Retrieved 13 January 2024. He further alleges that the chairman, instead of stating the truth that it was an error in the software that had caused the failure in the landing of Chandrayaan 2, declared that contact could not be established with the lander. Sivan made several changes to the Chandrayaan 2 mission, which started when Kiran Kumar was the chairman. Excessive publicity also affected the Chandrayaan 2 mission adversely.
  198. ^ "Haven't Targeted Anyone In Autobiography, Says ISRO Chief S Somanath". NDTV.com. Retrieved 13 January 2024. He admitted that he mentioned in his book the lack of clarity in connection with the announcement of the failure of the Chandrayaan-2 mission. During the time of landing, it was not clearly said that there was communication failure and it would crash land, he said. "I believe that a good practice is to tell what has actually happened. It will increase transparency in the organisation. So I referred to that particular incident in the book," Mr Somanath added.
  199. ^ Koshy, Jacob (4 November 2023). "ISRO Chairman Somanath withdraws memoir after controversy". The Hindu. ISSN 0971-751X. Retrieved 13 January 2024. "That a software glitch was at fault was known only subsequently. However, the crashing of the lander was known on that day itself (September 6, 2019). There was no point in calling it a communication failure... [as Chairman Sivan had described it]. However, every Chairman can choose what they communicate. I believe that whatever success or failure happens should be transparently communicated. I'm not criticising Dr. Sivan though," said Mr. Somanath.
  200. ^ "At Bangalore mission control, all eyes on Mars". The Indian Express. 16 December 2013. Archived from the original on 2 August 2019. Retrieved 2 August 2019.
  201. ^ The women, and men, behind Chandrayaan-2 Archived 27 July 2020 at the Wayback Machine Madhumathi D.S., The Hindu 15 July 2019
  202. ^ Chandrayaan-2: India launches second Moon mission Archived 22 August 2019 at the Wayback Machine BBC News 22 July 2019
  203. ^ "Chandrayaan-2 deputy project director taught village students to fund his education". The Times of India. 30 July 2019. Archived from the original on 9 September 2019. Retrieved 23 August 2019.
  204. ^ "BENGALURU, KARNATAKA, INDIA. Ms K. Kalpana, an electrical engineer at..." Getty Images. 19 June 2019. Archived from the original on 27 July 2020. Retrieved 11 September 2019.
  205. ^ Rajwi, Tiki (14 July 2019). "The Malayali hand in Chandrayaan-2". The Hindu. ISSN 0971-751X. Archived from the original on 27 July 2020. Retrieved 11 September 2019.
  206. ^ Subramanian, T. S. (28 September 2016). "Cryogenic gains for GSLV". Frontline. Archived from the original on 27 July 2020. Retrieved 11 September 2019.
  207. ^ "Amitabh Singh | MTech | Indian Space Research Organization, Bengaluru | ISRO | signal & Image Processing | ResearchGate". Research Gate. Archived from the original on 30 September 2015. Retrieved 26 August 2019.
  208. ^ "A mix of young and middle-aged people will train for Gaganyaan". The Week. Archived from the original on 28 January 2020. Retrieved 28 January 2020. The work on Chandrayaan-3 is also going on; it should be launched in the next 16 months or so.
  209. ^ "Unstarred Question no. 1384 in Lok Sabha". 164.100.47.194. Archived from the original on 27 November 2019. Retrieved 27 November 2019.
  210. ^ "ISRO Will Embark on Chandrayaan-3 by November 2020 for Another Landing Attempt". The Wire. 14 November 2019. Archived from the original on 27 July 2020. Retrieved 13 May 2020.
  211. ^ "NASA – NSSDCA – Spacecraft – Details". Archived from the original on 8 June 2022. Retrieved 10 June 2022.
  212. ^ Kumar, Chethan (14 November 2019). "Chandrayaan-3: Second bid to land on Moon by November 2020". The Times of India. Archived from the original on 16 November 2019. Retrieved 15 November 2019.
  213. ^ "ISRO Will Embark on Chandrayaan-3 by November 2020 for Another Landing Attempt". The Wire. 14 November 2019. Archived from the original on 15 November 2019. Retrieved 15 November 2019.
  214. ^ "ISRO Will Attempt Another Soft-Landing on the Moon 'in the Near Future'". The Wire. 2 November 2019. Archived from the original on 15 November 2019. Retrieved 15 November 2019.
  215. ^ "CHANDRAYAAN-III" (Press release). Delhi. Press Information Bureau. 27 November 2019. Archived from the original on 28 July 2020. Retrieved 1 December 2019.
  216. ^ Kumar, Chethan (8 December 2019). "ISRO seeks 75 crore more from Centre for Chandrayaan-3". The Times of India. Archived from the original on 20 January 2021. Retrieved 8 December 2019.
  217. ^ "Chandrayaan-3 to cost Rs 615 crore, launch could stretch to 2021". The Times of India. 2 January 2020. Archived from the original on 30 December 2020. Retrieved 2 January 2020.
  218. ^ Hrishikesh, Sharanya; Pandey, Vikas, eds. (23 August 2023). "Chandrayaan-3 live: India's Vikram lander makes historic Moon landing". BBC News. Archived from the original on 23 August 2023. Retrieved 23 August 2023.
[edit]
Wikimedia Commons has media related to Chandrayaan-2.
Retrieved from "https://en.wikipedia.org/w/index.php?title=Chandrayaan-2&oldid=1255942696"