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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Chandrayaan-2 | 3/6 | https://en.wikipedia.org/wiki/Chandrayaan-2 | reference | science, encyclopedia | 2026-05-05T12:59:52.302451+00:00 | kb-cron |
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. 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. 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. It has lunar surface penetration depth of 5 m (16 ft) (L-band). 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. 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. 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. The Terrain Mapping Camera-2 (TMC-2) from SAC for preparing a three-dimensional map essential for studying the lunar mineralogy and geology 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 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.
=== Vikram lander === The payloads on the Vikram lander were:
Instrument for Lunar Seismic Activity (ILSA) MEMS based seismometer by LEOS for studying Moon-quakes near the landing site Chandra's Surface Thermo-physical Experiment (ChaSTE) thermal probe jointly developed by SPL, Vikram Sarabhai Space Centre (VSSC) and Physical Research Laboratory (PRL), Ahmedabad for estimating the thermal properties of the lunar surface RAMBHA-LP Langmuir probe by SPL, VSSC for measuring the density and variation of lunar surface plasma A laser retroreflector array (LRA) by the Goddard Space Flight Center for taking precise measurements of distance between the reflector on the lunar surface and satellites in lunar orbit. The microreflector weighed about 22 g (0.78 oz) and cannot be used for taking observations from Earth-based lunar laser stations.
=== Pragyan rover === Pragyan rover carried two instruments to determine the abundance of elements near the landing site:
Laser induced Breakdown Spectroscope (LIBS) from the laboratory for Electro Optic Systems (LEOS), Bangalore Alpha Particle Induced X-ray Spectroscope (APXS) from PRL, Ahmedabad
== Mission profile ==
=== Launch ===
The launch of Chandrayaan-2 was initially scheduled for 14 July 2019, 21:21 UTC (15 July 2019 at 02:51 IST local time). 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. Unconfirmed reports later cited a leak in the nipple joint of a helium gas bottle as the cause of cancellation. 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. This also resulted in the saving of around 40 kg fuel on board the spacecraft. 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.
=== Geocentric phase ===
After being placed into a 45,475 × 169 km parking orbit by the launch vehicle, 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 followed by trans-lunar injection on 13 August 2019. 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. 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.
=== Selenocentric phase === 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. 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. 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 followed by separation of Vikram lander from the orbiter on 07:45 UTC, 2 September 2019.
=== Planned landing site ===
Two landing sites were selected, each with an ellipse of 32 km × 11 km (19.9 mi × 6.8 mi). The prime landing site (PLS54) was at 70.90267°S 22.78110°E (600 km (370 mi) from the south pole,) 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, on the near side of the Moon.
=== Failed landing attempt ===