Chandrayaan 1 and Technology Used to Find Water on the Moon

Indian Space Research Organisation (ISRO) has done the country proud yet again. India’s first lunar probe Chandrayaan 1 has confirmed the presence of frozen water deposits on the Moon. NASA has confirmed through a statement on its website that a group of scientists has observed definitive evidence of water on the Moon. NASA says that the frozen water deposits are patchily distributed on the darkest and coldest areas and could also be ancient.

“A team of scientists, led by Shuai Li of the University of Hawaii and Brown University and including Richard Elphic from NASA's Ames Research Center in California's Silicon Valley, used data from NASA's Moon Mineralogy Mapper (M3) instrument to identify three specific signatures that definitively prove there is water ice at the surface of the Moon,” said NASA’s Jet Propulsion Laboratory Website.

Chandrayaan 1, which was launched in October 2008 using a PSLV-XL rocket, has a lunar orbiter and impactor. The lunar mission not only carried five payloads of ISRO, but also carried payloads of six other space agencies like NASA, ESA and the Bulgarian Aerospace Agency without charging them anything for doing the same. However, a year after its launch the mission was over as the orbiter started suffering from technical issues and stopped sending signals altogether in August 2009.  Nevertheless, seven years after the lunar mission was shut down, NASA used ground-based radar systems to relocate Chandrayaan-1 and was successful in doing so.

So far, vast data has been collected about the Moon, its origin, atmospheric constituents, mineral content and other relative information. Let us take a look into the instruments that are onboard Chandrayaan 1, which are providing data to scientists across the world.

Instruments and Technology Used in Chandrayaan 1

The main Indian instruments aboard the lunar mission are Terrain Mapping Camera (TMC) and Hyper Spectral Imager (HySi). The TMC, which was developed by ISRO’s Space Application Centre (SAC) in Ahmadabad, has 5 metres spatial resolution and 20 km swath and therefore is capable of providing high resolution digital elevation models of the moon. ISRO says on its website that using TMC, Chandrayaan 1 has acquired data sets for nearly 1003 orbits covering equatorial and polar regions of the Moon.

Another instrument on Chandrayaan 1 is the Hyper Spectral Imager, which is a complementary metal oxide semiconductor camera with a ground resolution cell of approximately 80 metres and has the capability to map the lunar surface in the spectral range of 0.42 to 0.96 micrometre in 64 contiguous spectral bands. The high spatial and spectral resolution data from the HySI instrument helps in mapping the major mineral resources of the Moon and also in understanding the lunar crustal evolutionary processes.

Four other Indian instruments onboard are as follows: Lunar Laser Ranging Instrument to determine the height of the surface topography using infrared laser light; High Energy X-ray Spectrometer or HEX to measure degassing of radioactive materials like Uranium, Thorium, Lead and isotopes of radon; and Moon Impact Probe which carried a video imaging system to provide images of the lunar surface and a mass spectrometer to provide information on the atmospheric constituents of the Moon.

The data from terrain mapping camera when used in combination with data from lunar laser ranging instrument can also provide valuable inputs about the lunar gravitational field.

Moon Mineralogy Mapper and Instruments from Other Countries

The instrument that detected frozen water on the surface of the Moon is M3 or Moon Mineralogy Mapper, which was NASA’s contribution to Chandrayaan 1. M3 is basically an imaging spectrometer that provides a spectral map of the entire lunar surface thereby providing information also on the minerals it constitutes. NASA has also said on its website that based on M3’s findings, water could be accessible as a resource for future expeditions to explore and even stay on the Moon.

Some other instruments from other countries are X-ray fluorescence spectrometer, Sub-keV Atom Reflecting Analyser or SARA, SIR 2, Mini-SAR and Radiation Dose Monitor Experiment or RADOM-7. M3 has previously already confirmed that the moon was once in a completely molten state. This theory is popularly known as the magma ocean hypothesis. ISRO’s TMC has also found and captured pictures of the landing site of the US aircraft Apollo 15.