5th Engine

BENGALURU: In the most recent review meeting of Chandrayaan-2 , scientists have recommended that January 30, not January 3 as Isro has now announced, will be the most optimal date for the launch of India’s second mission to Moon The review committee had looked into three dates that were conceived as the best for Isro in the January and March window that’s available for the launch. “One could achieve a launch on any date during this window, but generally scientists study various prospects and pick one date that is the best,” one scientist explained.TOI has learnt reliably that the committee looked into January 3, January 30, and February 14 as the three dates for the launch and after all deliberations, it was said: “January 30 will be a good option for Chandrayaan-2 launch since there is a 27kg propellant advantage with respect to January 3 launch.”Chandrayaan-2, unlike the first mission, involves a Lander soft-landing on the lunar surface and unloading a Rover to study and take measurements from the Moon, while the orbiter will go around the Earth’s satellite. Initially, the project was to be a joint mission with Russian, whose space agency Roscosmos was to supply the lander. However, that deal fell through and Isro decided to go solo.Among other things discussed in the September 19 Comprehensive Technical Review (CTR) were the agreed parameters of the GSLV, a few tests required for the Vikas engine, need to carry out all the hardware and software failure test scenarios.“The new configuration has seen a host of new systems being added, for which the algorithms will also change,” one source working with the project said.Besides, the committee also looked into two issues of the crucial fifth engine that has been added as part of the new configuration of the Lander. First, the thermal management and second, prevention of hot gas entry to engine chamber through the nozzle exit.TOI had reported in September that among the many challenges that Isro has to overcome was the fact that this engine—without which the project will not work in the new configuration—had to be requalified. The engine had failed a test earlier this year, but Isro Chairman Sivan K had clarified: “The test was wrongly done, the engine is fine and we will be able to use it.”For the heat management, a conical heat shield has been preferred, which the project team has said can be accommodated, while several options are being worked out for the second issue (hot gas entry).