The Rs. 425-crore mission will be launched in 2013

India's second moon mission, Chandrayaan-II, will carry seven indigenous payloads. Two of these scientific instruments will be carried by a rover, which will detach itself from the satellite and make a soft-landing.

3 new payloads

Of the five payloads in the orbiter (main satellite), three are new and the rest “improved versions” of payloads flown on Chandrayaan–I, an Indian Space Research Organisation (ISRO) press release said on Monday. The Rs. 425-crore mission is scheduled to be launched in 2013.

A Large Area Soft X-ray Spectrometer (CLASS) from the ISRO Satellite Centre (ISAC) and Solar X-ray Monitor (XSM) from the Physical Research Laboratory (PRL), Ahmedabad, will map the major elements on the lunar surface. This payload is similar to Chandrayaan-I's X-ray Spectrometer (C1XS), designed for X-ray spectroscopic mapping.

An L and S band Synthetic Aperture Radar (SAR) from the Space Applications Centre (SAC), Ahmedabad, will probe the first few tens of meters of the lunar surface to detect different constituents, including water ice.

The Imaging IR Spectrometer (IIRS) from the SAC will map the lunar surface with a wide wavelength range to study minerals, water molecules and hydroxyl. The Neutral Mass Spectrometer (ChACE–2) from the Space Physics Laboratory, Thiruvananthapuram, will study the lunar exosphere.

The Terrain Mapping Camera–2 (TMC–2) from the SAC will prepare a three-dimensional map to study mineralogy and geology. The first one on board Chandrayaan-I did not meet its target entirely as the mission was called off prematurely 10 months after launch.

Two payloads on the rover will carry out elemental analysis of the surface near the landing site. These comprise a Laser Induced Breakdown Spectroscope from Laboratory for Electro Optic Systems, Bangalore, and an Alpha Particle Induced X –ray Spectroscope (APIXS) from the PRL.

The 1,250 kg lander (provided by Russia) and wheeled rover will detach from the main satellite once it reaches its orbit, and land on the surface where the instruments will analyse the terrain near the landing site.

Asked why foreign payloads are not part of this mission, PRL director J.N. Goswami said the mass specifications of the mission had to be considered. “Besides, we do have a Russian lander.”

Chandrayaan-I carried 11 instruments and of them, six were foreign.

Heavy lander

U.R. Rao, Chairman, Advisory Committee on Space Sciences and the former Chairman of ISRO, told The Hindu that the heavy lander limited the payload weight to approximately 40 kg.

Chandrayaan-II, with a lift-off weight of 2,650 kg, will be launched by a Geosynchronous Satellite Launch Vehicle from the Satish Dhawan Space Centre in Sriharikota.

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