From UPSC perspective, the following things are important :
Prelims level : Chandrayaan-3 Mission
Mains level : Accomplishments of India's Lunar Mission
The failure of Chandrayaan-2, India’s second mission to the Moon, to make a soft landing on the lunar surface had led to much disappointment. But that did not mean the entire mission had been wasted.
Chandrayaan-2: A quick recap
- Chandrayaan-2 consisted of an Orbiter, Lander and Rover, all equipped with scientific instruments to study the moon.
- The Orbiter would watch the moon from a 100-km orbit, while the Lander and Rover modules were to be separated to make a soft landing on the moon’s surface.
- ISRO had named the Lander module as Vikram, after Vikram Sarabhai, the pioneer of India’s space programme, and the Rover module as Pragyaan, meaning wisdom.
Utility of the Orbit
- The Orbiter part of the mission has been functioning normally. It is carrying eight instruments.
- Each of these instruments has produced a handsome amount of data that sheds new light on the moon and offers insights that could be used in further exploration.
Some of the most significant results so far:
- The presence of water on the Moon had already been confirmed by Chandrayaan-1, India’s first mission to the Moon that flew in 2008.
- Using far more sensitive instruments, the Imaging Infra-Red Spectrometer (IIRS) onboard Chandrayaan-2 has been able to distinguish between hydroxyl and water molecules and found unique signatures of both.
- This is the most precise information about the presence of H2O molecules on the Moon to date.
- Previously, water was known to be present mainly in the polar regions of the Moon.
- Chandrayaan-2 has now found signatures of water at all latitudes, although its abundance varies from place to place.
(b) Minor elements
- The Large Area Soft X-ray Spectrometer (CLASS) measures the Moon’s X-ray spectrum to examine the presence of major elements such as magnesium, aluminum, silicon, calcium, titanium, iron, etc.
- This instrument has detected the minor elements chromium and manganese for the first time through remote sensing, thanks to a better detector.
- The finding can lay the path for understanding magmatic evolution on the Moon and deeper insights into the nebular conditions as well as planetary differentiation.
- CLASS has mapped nearly 95% of the lunar surface in X-rays for the first time.
- Sodium, also a minor element on the Moon surface, was detected without any ambiguity for the first time.
(c) Study of Sun
- One of the payloads, called Solar X-ray Monitor (XSM), besides studying the Moon through the radiation coming in from the Sun, has collected information about solar flares.
- XSM has observed a large number of microflares outside the active region for the first time.
- This has great implications on the understanding of the mechanism behind the heating of the solar corona, which has been an open problem for many decades.
Utility of this Data
- While the Orbiter payloads build upon existing knowledge of the Moon in terms of its surface, sub-surface and exosphere, it also paves the path for future Moon missions.
- Four aspects — mineralogical and volatile mapping of the lunar surface, surface and subsurface properties and processes involved, quantifying water in its various forms across the Moon surface, and maps of elements present on the moon — will be key for future scope of work.
- A key outcome from Chandrayaan-2 has been the exploration of the permanently shadowed regions as well as craters and boulders underneath the regolith, the loose deposit comprising the top surface extending up to 3-4m in depth.
- This is expected to help scientists to zero in on future landing and drilling sites, including for human missions.
Who is going to use it?
- Some key future Moon missions that hope to make use of such data include the Japan Aerospace Exploration Agency (JAXA)-ISRO collaboration Lunar Polar Exploration (LUPEX) mission scheduled for launch in 2023/2024.
- Its aim is to obtain knowledge of lunar water resources and to explore the suitability of the lunar polar region for setting up a lunar base.
- NASA’s Artemis missions plan to enable human landing on the Moon beginning 2024 and target sustainable lunar exploration by 2028.
- The Chinese Lunar Exploration Programme too plans to establish a prototype of the International Lunar Research Station (ILRS) at the lunar south pole and build a platform supporting large-scale scientific exploration.
What was missed because of the crash-landing?
- The most obvious miss has been the opportunity to demonstrate the technology to make a soft landing in outer space.
- The lander Vikram and rover Pragyaan were carrying instruments to carry out observations on the surface.
- These were supposed to pick up additional information about the terrain, and composition, and mineralogy.
- While the instruments onboard the Orbiter is making “global” observations, those on the lander and rover would have provided much more local information.
- The two diverse sets of data could have helped prepare a more composite picture of the Moon.
Future with the Chandrayaan-3
- ISRO scientists maintain that the accident was caused by a relatively small error that has been identified and corrected.
- But, to demonstrate this technology all over again, ISRO would have to send a fresh mission, Chandrayaan-3, planned for next year.
- It is expected to have only a lander and rover, and no Orbiter.