How an objective analysis helped ISRO create history with Chandrayaan-3

ISRO’s success with Chandrayaan-3 is due to efficient performance analysis and improvements, Dr. Narayanan noted. ISRO bounced back in style with Chandrayaan-3, thanks to efficient performance analysis and improvements. Dr. Narayanan chaired the national-level expert committee which analysed the reasons for the 2019 Chandrayaan-2 lander crash and recommended vital improvements that were incorporated in Chandrayaan-3. ISRO's success due to efficient performance analysis and improvements, noted Dr. Narayanan.

The August 23 moon landing scored by the Indian Space Research Organisation (ISRO) with its Chandrayaan-3 mission is also the story of how an efficient performance analysis helped the space agency bounce back in style from a setback, V. Narayanan, Director, Liquid Propulsion Systems Centre (LPSC), has noted.

Dr. Narayanan, who has headed the LPSC since January 2018, had chaired the national-level expert committee which analysed the reasons for the 2019 Chandrayaan-2 lander crash and recommended vital improvements that were incorporated in Chandrayaan-3.

“A multidisciplinary review by the nine-member panel had analysed all aspects of the Chandrayaan-2 spacecraft’s performance and submitted its report within a month. Improvements were recommended in most of the systems to enhance their reliability. Practically all the recommendations, barring one or two which were not seen as vital, were implemented,” Dr. Narayanan told The Hindu on Monday.

The Chandrayaan-2 mission, launched in July 2019 from Sriharikota, had performed normally until contact with its ‘Vikram’ lander was lost at an altitude of 2.1 km amid its descent to the lunar landing site.

The committee analysed and suggested improvements to the software packages, the navigation, guidance control systems, the propulsion mechanism and the powered descent scheme, and the Vikram lander system, among other things. Its recommendations included enhancing the propellant margin in the spacecraft, and strengthening the lander legs. ‘‘The entire software system was verified, validated and strengthened, because once the powered descent (to the lunar surface) starts, everything is autonomous and has to work with precision,’‘ Dr. Narayanan said.

A rocket propulsion expert who began his career with ISRO in 1984, he described Chandrayaan-3 as “a perfect mission” where all components functioned splendidly to make India the first nation to soft-land on the lunar south pole.

ISRO’s ‘liquid propulsion community’ — LPSC and the ISRO Propulsion Complex (IPRC), Mahendragiri — made vital contributions to the Chandrayaan-3 mission, he said. The LPSC contributed four propulsion systems for the mission — the L110 core liquid stage and the C25 cryogenic upper stage for the LVM3 launch vehicle, one for the Propulsion Module and one for the Vikram lander which touched down on the lunar surface.