Chandrayaan-2

Chandrayaan-2 (Sanskrit: चन्द्रयान-२; Sanskrit: [ t͡ʃʌnd̪ɾʌːjaːn d̪ʋi]; lit: Moon-vehicle^[2][3]  pronunciation ), is India's second lunar exploration mission after Chandrayaan-1. Developed by the Indian Space Research Organisation (ISRO), the mission is planned to be launched to the Moon by a Geosynchronous Satellite Launch Vehicle (GSLV),^[4] includes a lunar orbiter, a lander and a lunar rover, all developed by India. India is planning to launch Chandrayaan-2 by 2018.^[5][6]

According to ISRO, this mission will use and test various new technologies and conduct new experiments.^[7][8][9] The wheeled rover will move on the lunar surface and will pick up soil or rock samples for on-site chemical analysis. The data will be relayed to Earth through the Chandrayaan-2 orbiter.^[10]

History

On November 12, 2007, representatives of the Russian Federal Space Agency (Roskosmos) and ISRO signed an agreement for the two agencies to work together on the Chandrayaan-2 project.^[11] ISRO would have the prime responsibility for the orbiter and rover, while Roskosmos was to provide the lander.

The Indian Government approved the mission in a meeting of the Union Cabinet held on 18 September 2008 chaired by Prime Minister Manmohan Singh.^[12] The design of the space craft was completed in August 2009, with scientists of both countries conducting a joint review.^[13][14]

Although ISRO finalized the payload for Chandrayaan-2 per schedule,^[15] the mission was postponed,^[4] and rescheduled to 2016 because Russia was unable to develop the lander on time.^[16][17] Later Roscosmos withdrew in wake of the failure of the Russian Phobos-Grunt mission to Mars, reason being technical aspects connected with the Phobos-Grunt mission were also used in the lunar projects, which need to be reviewed.^[16] When Russia cited its inability to provide the lander even by 2015, India decided to develop the lunar mission independently.^[4]

Design

The mission is planned to fly on a Geosynchronous Satellite Launch Vehicle Mk-II (GSLV) with an approximate lift-off mass of 2,650 kg from Satish Dhawan Space Center on Sriharikota Island.^[18]

Orbiter

ISRO will design the orbiter, which will orbit the Moon at an altitude of 200 km.^[19] The mission would carry five instruments on the orbiter. Three of them are new, while two others are improved versions of those flown on Chandrayaan-1 orbiter. The approximate launch mass will be 1,400 kg.^[15][18]

Lander

Unlike Chandrayaan-1's lunar probe, which impacted the Moon's surface, the lander will make a soft landing to then deploy the rover.^[18] The lander will not perform any scientific activities. The approximate mass of the lander and rover is 1,250 kg. Initially, the lander was slated to be developed by Russia in collaboration with India. When Russia stated its inability provide the lander to meet even the revised time frame of 2015, Indian officials decided to develop the lander independently. The cancellation of the Russian lander also meant that mission profile had to be changed. The design of the indigenous lander and the preliminary configuration study has been completed by the Space Applications Centre (SAC) in Ahmedabad.^[4]

Rover

The rover's mass will be about 30–100 kg and will operate on solar power. The rover will move on wheels on the lunar surface, pick up samples of soil or rocks, perform on-site chemical analysis and send the data to the orbiter above, which will relay it to the Earth station.^[15][18]

The initial plan was for the rover to be designed in Russia and fabricated in India. However, Russia gave up in May 2010 on its plan on designing the rover.^[4][16][17] Subsequently, ISRO decided on designing and fabricating the rover. IIT Kanpur is developing three subsystems to provide mobility:

1. Stereoscopic camera based 3D vision - will provide the ground team controlling the rovers a 3D view of the surrounding terrain.
2. Kinematic traction control - will enable the rover to negotiate the rough lunar terrain using independent steering provided on four of its wheels.
3. Control and motor dynamics - The rover will have six wheels, each driven by an independent electric motor. Four of the wheels will also be capable of independent steering. A total of 10 electric motors will be used for traction and steering.

Spacecraft redesign

Once it became clear that Chandrayaan-2 would have to be launched by GSLV and not GSLV-III, the structure configuration of the spacecraft was changed from I2K to I3K to accommodate a revision in payload lift off capacity. The change will facilitate the use of larger propellant tanks.

The mission strategy was revised to inject the satellite in a lower initial orbit (170 X 16980 km) with a higher lift-off mass of 3200 kg and the propulsion system configuration changed to increase fuel carrying capability of the satellite. ^[6]

Payload

ISRO has announced that an expert committee has decided on five payloads for the orbiter, and two for the rover.^[15][20] While it was initially reported that NASA and ESA would participate in the mission by providing some scientific instruments for the orbiter,^[21] ISRO has later clarified that due to weight restrictions it will not be carrying foreign payloads on this mission.^[19]

Orbiter payload

• Large Area Soft X-ray Spectrometer (CLASS) from ISRO Satellite Centre (ISAC), Bangalore and Solar X-ray monitor (XSM) from Physical Research Laboratory (PRL), Ahmedabad for mapping major elements present on the lunar surface.^[15]

• L and S band Synthetic Aperture Radar (SAR) from Space Applications Centre (SAC), Ahmedabad for probing the first few tens of metres of the lunar surface for the presence of different constituents, including water ice. SAR is expected to provide further evidence confirming the presence of water ice below the shadowed regions of the Moon.^[15]

• Imaging IR Spectrometer (IIRS) from SAC, Ahmedabad for mapping of lunar surface over a wide wavelength range for the study of minerals, water molecules and hydroxyl present.^[15]

• Neutral Mass Spectrometer (ChACE-2) from Space Physics Laboratory (SPL), Thiruvananthapuram to carry out a detailed study of the lunar exosphere.^[15]

• Terrain Mapping Camera-2 (TMC-2) from SAC, Ahmedabad for preparing a three-dimensional map essential for studying the lunar mineralogy and geology.^[15]

Rover payload

• Laser induced Breakdown Spectroscope (LIBS) from Laboratory for Electro Optic Systems (LEOS), Bangalore.^[15]

• Alpha Particle Induced X-ray Spectroscope (APIXS) from PRL, Ahmedabad.

There are plans to include a seismometer to study Moon-quakes.^[22]

See also

• Chandrayaan-1
• Chang'e 2
• Exploration of the Moon
• List of current and future lunar missions
• List of ISRO missions

References

External links

• Chandrayaan 2 updates

Indian space programme Indian Space Research Organisation (ISRO) Organisations Department of Space (DoS) Antrix Corporation Indian Institute of Space Science and Technology (IIST) Indian Institute of Remote Sensing (IIRS) Laboratory for Electro-Optics Systems (LEOS) National Atmospheric Research Laboratory (NARL) Physical Research Laboratory (PRL) Physical Research Laboratory (DECU) Programmes Bhaskara GAGAN GSAT INSAT IRNSS IRS Cartosat RISAT Rohini SROSS Chandrayaan Human spaceflight programme Orbital Vehicle Indian Space Shuttle Programme Spacecraft One-off missions APPLE Aditya Aryabhata Astrosat HAMSAT IMS-1 Megha-Tropiques NISAR SARAL SAARC Satellite SRE Kalpana-1 CARE Planetary missions Chandrayaan-1 Chandrayaan-2 Mars Orbiter Mission Mangalyaan 2 Venus orbiter mission Rockets Orbital SLV ASLV PSLV GSLV GSLV Mk.III Suborbital Rohini Concept RLV-TD AVATAR ULV Under Development Indian TSTO Facilities Indian Deep Space Network (IDSN) ISRO Satellite Centre (ISAC) ISRO Telemetry, Tracking and Command Network (ISTRAC) Master Control Facility (MCF) Satish Dhawan Space Centre (SDSC) Thumba Equatorial Rocket Launching Station (TERLS) See also SAGA-220 List of Indian satellites List of Satish Dhawan Space Centre launches List of ISRO missions