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Chandrayaan-2

Chandrayaan-2 (; 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.

Mission type

44441

  • Orbiter: ~ 7.5 years (planned);
    4 years, 10 months, 5 days (elapsed)
  • Vikram lander: ≤ 14 days (planned);[1][2]
    0 days (landing failure)
  • Pragyan rover: ≤ 14 days (planned);[2]
    0 days (not deployed)

ISRO

Combined (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]

Orbiter: 1000 watts [7]
Vikram lander: 650 watts [8]
Pragyan rover: 50 watts

22 July 2019, 09:13:12 UTC[9]

ISRO

20 August 2019, 03:32 UTC [12][13]

100 km (62 mi) [14]

100 km (62 mi)

6 September 2019, 20:23 UTC [13][15]

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 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]

to study , mineralogy, elemental abundance, the lunar exosphere, and signatures of hydroxyl and water ice;[53][54]

lunar topography

to study the water ice in the and thickness of the lunar regolith on the surface;[55] and

south polar region

to map the lunar surface and help to prepare 3D maps of it.

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

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 [8]

watts

Mission duration: ~ 7.5 years, extended from the planned 1 year owing to the precise launch and mission management, in lunar orbit [65]

[1]

The Chandrayaan-2 Large Area (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]

Soft X-ray Spectrometer

The Solar X-ray monitor (XSM) from (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]

Physical Research Laboratory

The Dual Frequency 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]

L-band

The (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]

Imaging IR Spectrometer

The Chandrayaan-2 Atmospheric Compositional Explorer 2 (ChACE-2) Quadrupole Mass Analyzer from Space Physics Laboratory (SPL), designed for carry out a detailed study of the lunar exosphere.[21]

[108]

The Terrain Mapping Camera-2 (TMC-2) from SAC for preparing a three-dimensional map essential for studying the lunar mineralogy and geology [109]

[21]

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 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]

digital elevation models

Detection of sodium: In October 2023, the orbiter discovered an abundance of sodium on the Moon. 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.

[123]

Hydroxyl and Water molecules: The 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.

Chandrayaan-1

Distribution of Gas in : 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.

Lunar Atmosphere

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.

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

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]

– Mission Director

Ritu Karidhal

– Project Director

Muthayya Vanitha

– Associate Project Director [204]

Kalpana Kalahasti

G. Narayanan – Associate Project Director

[205]

G. Nagesh – Project Director (former)

[206]

Chandrakanta Kumar – Deputy Project Director (Radio-frequency systems)

– Deputy Project Director (Optical Payload Data Processing, Space Applications Centre (SAC)) [207]

Amitabh Singh

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

– Concurrent lunar lander mission, crash-landed on the Moon

Beresheet lander

Chandrayaan-3

LUPEX

Exploration of the Moon

List of missions to the Moon

List of ISRO missions

Lunar resources

Archived 29 July 2019 at the Wayback Machine, by the Indian Space Research Organisation

Official Chandrayaan-2 mission page

Archived 12 September 2019 at the Wayback Machine, by the Indian Space Research Organisation

GSLV-Mk III launcher