(This was originally posted in Times Of India by Chethan Kumar)
With ISRO racing against time to launch the first uncrewed mission as part of Gaganyaan, the space agency’s other big-ticket mission aimed at landing equipment on the lunar surface — Chandrayaan-3 — may have to wait its turn even as work on the project continues across centres. Multiple scientists associated with Chandrayaan-3 told STOI that testing and fabrication of the lander and other systems that’ll be part of the Moon mission is ongoing at various Isro centres and that the design changes have been finalised.
ISRO conceived Chandrayaan-3 after it failed to soft-land Vikram (lander) on the lunar surface while it still has a fully operational orbiter of Chandrayaan-2 going around the Moon. Therefore, unlike the previous mission, which carried an orbiter, lander and rover, Chandrayaan-3 will only carry a lander and rover along with a propulsion module that will carry the fuel for various manoeuvres needed to navigate the landing module after its launch.
A senior scientist from the Isro headquarters said: “Given the scope and scale of Gaganyaan, the need to launch the first uncrewed mission as early as possible is clearly a priority. While we continue to work on Chandrayaan, it is likely to get postponed.”Another scientist, while pointing out that Gaganyaan’s uncrewed mission is crucial to ascertain whether or not the actual human mission can be launched within the deadline set by Prime Minister Narendra Modi, said: “We are still looking at 2022, but it will depend on the overall readiness.” While the mission was initially planned for late 2020 or 2021, the department of space (DoS), owing to Covid-19 had said earlier this year that the launch is being targeted for 2022. “Given that the Moon mission will need a specific launch window, we will have to see if it will be possible,” a source said.
As reported first by TOI, Chandrayaan-3 will see major design changes compared to the previous mission, key among which is the decision to drop the fifth engine, which was added last minute on Vikram (Chandrayaan-2’s lander).
The lander for this mission will have only four engines, while the overseeing committee has also suggested a minor modification on the legs on the lander, the inclusion of the laser doppler velocimeter (LDV) for better measurement of speed during landing, among other things. The modifications being proposed on Chandrayaan-3 — which were indicators of shortcomings in Chandrayaan-2 — also include changes in software and algorithms, strengthening of the legs, and better power and communication systems.