Chandrayaan 3: From finding water to mapping sodium - what ISRO's previous Moon missions achieved

As ISRO prepares for the Chandrayaan-3 landing, here's a look at the astounding discoveries made by India's previous Moon missions, and how Chandrayaan 3 plans to add to the list.

The Chandrayaan 1 orbiter was launched in 2008, and it achieved its aim of detecting water on the Moon. ISRO lost contact with Chandrayaan 1 in August 2009, but not before it sent an impact probe to deliberately crash on the Moon.

Chandrayaan 2 was launched in 2019, and it mapped an abundance of sodium on the Moon for the first time. While Chandrayaan 2's lander failed, the orbiter module is still in operation around the Moon.

The rover on Chandrayaan 3 will analyse the composition of lunar dust and rocks, and measure temperature and seismicity around the landing site. It will also study light emitted and reflected by the Earth.

The significance about Chandrayaan-3 mission, unlike its unsuccessful predecessor, is that the Propulsion Module has a payload -- SHAPE -- Spectro- polarimetry of HAbitable Planet Earth to study Earth from lunar orbit.

ISRO said the SHAPE is an experimental payload to study the spectro-polarimetric signatures of the Earth in the near-infrared wavelength range.

Apart from the SHAPE payload, the Propulsion Module's main function is to carry the Lander Module from the launch vehicle injection orbit to till lander separation.

Also watch: Chandrayaan 3 landing: What's next after Moon mission? Here's what ISRO is planning

The lander module after landing on the surface of the moon has payloads including RAMBHA-LP which is to measure the near-surface plasma ions and electrons density and its changes, ChaSTE Chandra's Surface Thermo Physical Experiment -- to carry out the measurements of thermal properties of the lunar surface near-polar region and ILSA (Instrument for Lunar Seismic Activity) to measure seismicity around the landing site and delineating the structure of the lunar crust and mantle.

The Rover, after the soft-landing, would come out of the lander module and study the surface of the moon through its payloads APXS - Alpha Particle X-Ray Spectrometer - to derive the chemical composition and infer mineralogical composition to further enhance understanding of the lunar surface.

Rover, which has a mission life of 1 lunar day (14 Earth days) also has another payload Laser Induced Breakdown Spectroscope (LIBS) to determine the elemental composition of lunar soil and rocks around the lunar landing site, ISRO said.

(With PTI inputs)