The practice run for that mission in turn was the Chandrayaan-1 mission, which successfully inserted an orbiter around Moon, which functioned for eight months.
With each mission functioning as a test for a subsequent mission with additional complexity, the Chandrayaan-3 mission is also a test bed for the planned Indo-Japanese mission to Moon’s south pole, to be launched in the next three years.
With the Chandrayaan-3 launch scheduled to happen Thursday, ThePrint looks back — and ahead — at India’s lunar missions.
Also read: ‘Thanks for the ride,’ Chandrayaan-3’s Vikram lander successfully separates from spacecraft
Chandrayaan-1
Chandryaaan means ‘Moon vehicle’ in both Sanskrit and Hindi, and Chandrayaan-1 was the first lunar spacecraft launched from India. It lifted off in October 2008, and was an orbiter mission. It also carried an impactor, that was flung from the craft to the surface of the Moon for impact.
It inserted into orbit in November 2008 and functioned till August 2009, at which point ISRO lost communication with the orbiter, which continues to orbit to this day without any communiciation.
The same month after reaching orbit, the Moon Impact Probe (MIP) separated from the orbiter and crashed into the South Pole of the Moon, displacing the soil on the surface. This led to the discovery of water ice underneath, and both the MIP results as well as the results of the NASA payloads on Chandrayaan-1 confirmed the findings.
The orbiter carried a terrain mapping camera to produce a full, high-resolution map of the Moon, a hyperspectral imager to perform mineralogical mapping, a lunar laser ranging experiment to measure the height of the surface, a high energy gamma and x-ray spectrometer for measuring radioactive elements, and the MIP from ISRO.
It also carried foreign payloads — a UK-Europe-India collaborative X-ray fluorescent spectrometer (used for chemical analyses of rocks) to measure the abundance of some elements and monitor solar flux, an atom reflecting analysis per to map minerals on the surface, the Moon mineralogy mapper from NASA for the same purpose, an infrared spectrometer from European Space Agency (ESA) also for the mapping minerals, a synthetic aperture radar from US to search for lunar polar water ice, and a radiation monitor experiment from Bulgaria to map radiation on the Moon.
The mission confirmed the presence of lunar water ice, as well as the magma ocean hypothesis that states that the Moon was a ball of liquid rock in the past. The mineralogy mappers have provided high-resolution spectral data, the spectrometers monitored solar flares, detected underground tunnels, and high-quality data was sent from the spacecraft.
The mission was declared over when contact was lost, but the missing orbiter was relocated once again in 2016 by NASA’s ground-based radar systems.
However, the spacecraft still cannot communicate.
Chandrayaan-2
The Chandrayaan-2 consisted of an orbiter, lander, and rover, of which the lander which housed the rover famously crashed a few seconds before touchdown. The orbiter is still functional and is expected to aid in communications with the Chandrayaan-3’s lander.
Chandryaan-2 took off in July 2019.
This mission’s lander and rover were also named Vikram and Pragyan. The mission’s primary scientific objective was to map and study the lunar surface composition, including the abundance of water ice.
The orbiter carried payloads for X-ray fluorescence spectroscopy to study elements on the surface, solar X-ray monitor to study the Sun’s corona, a powerful synthetic aperture radar to probe the top few meters of the Moon’s surface for water ice, infrared spectrometer to look for water at different wavelengths, atmospheric composition analyser to study the exosphere, a terrain mapping camera for imaging geology, orbital camera to prepare maps, and atmospheric science experiment to study electron density in the ionosphere.
The lander and the rover carried identical payloads to the Chandrayaan-3 mission.
ISRO was criticised by the media for its lack of transparency about the reason for the lander’s crash, and it revealed this week that a software glitch caused it to crash 750m away from its intended location.
Chandrayaan-3
The present mission does not have an orbiter, but has a propulsion module that orbits the Moon and studies the Earth’s atmosphere from there. It was launched in July this year and is scheduled to land on Moon Wednesday.
The lander and rover together carry a total of six payloads.
The lander carries the Radio Anatomy of Moon Bound Hypersensitive ionosphere and Atmosphere (RAMBHA) to study the local gases and plasma in the Moon’s environment and their variations, the Chandra’s Surface Thermophysical Experiment (ChaSTE) to study the Moon’s thermal conductivity and surface temperature, the Instrument for Lunar Seismic Activity (ILSA) for measuring the seismicity around the landing site and a passive Laser Retroreflector Array (LRA) from NASA that will allow for lunar laser ranging studies.
Pragyan has two payloads — the Alpha Particle X-ray Spectrometer (APXS) and Laser Induced Breakdown Spectroscope (LIBS) which will analzye and map the elemental composition of the regolith (lunar soil) and negligible atmosphere in the neighborhood of the landing site.
LUPEX/Chandrayaan-4
ISRO’s next planned mission to the Moon is the Lunar Polar Exploration Mission (LUPEX), a planned collaboration with Japan Aerospace Exploration Agency (JAXA). The mission aims to send a lunar lander and rover to the Moon’s south pole, and it is expected to launch by or after 2026.
Japan will likely build the launch vehicle and the rover, while ISRO will build and operate the lander. It will carry payloads that will study the properties on the surface and drilled soil, and underneath. It will also look for water and water ice.
The mission is not approved or budgeted yet, and is in the early stages of being conceptualised. Chandrayaan-3’s success will provide a much-needed impetus to it.
(Edited by Poulomi Banerjee)
Also read: All about Chandrayaan-3 & how to watch it live — whip out the popcorn at 5.20 pm tomorrow