The Indian Space Research Organisation has resolved to attempt another autonomous soft-landing on the Moon by November 2020, Times of India reported today. Its previous attempt of this feat, as part of the Chandrayaan 2 mission, went awry on September 7 after the lander (carrying the rover inside) crashed on the Moon’s surface instead of descending slowly, and the surface mission was declared a failure.
For Chandrayaan 3, as the second attempt will be called, ISRO scientists will design and build a new lander and rover. Chandrayaan 2 also included an orbiter that underwent a successful orbital injection manoeuvre and is in orbit around the Moon now, so Chandrayaan 3 will not have an orbiter of its own. However, since the orbiter carried the engine and the fuel that carried the instruments from orbit around Earth to closer to the Moon in the previous mission, the new one will include an additional “detachable module”, to use Times of India‘s words, with the propulsion systems.
While ISRO scientists will be analysing data from the failed surface mission to figure out how they can improve Chandrayaan 3’s chances of success, they will also consider incorporating improvements an expert committee suggested for the previous mission and but which couldn’t be included for lack of time. One unnamed scientist told Times of India that “strengthening the legs of the lander” will be one of the priorities, to improve the lander’s chances of survival in the event of another crash.
Going back to the Moon was always on the cards for ISRO. To quote what Jatan Mehta, a space scientist, told The Wire in September:
If the lander fails, we must go back to the launchpad. If the rover fails, it is a smaller problem but we must still go back to the launchpad. If the orbiter fails: “heavy space systems to the lunar surface are for practical reasons expected to be modular”, so “the carrier modules need to be robust”, and we will likely to back to the launchpad. If the Mk III fails, “it’s more worse in certain ways: … if the capacity to launch remains similar or barely grows over time, all interplanetary missions would be limited.”
The private Israeli mission Beresheet, which flopped an autonomous soft-landing in April this year, also quickly announced it would take a second shot.
In fact, in June this year, well before the Chandrayaan 2 mission had commenced, ISRO chairman K. Sivan had told The Asian Age that the organisation was working with its Japanese counterpart, JAXA, to embark on yet another Moon mission together. At that time, Sivan had called that mission Chandrayaan 3, but with the new announcement, the ISRO-JAXA mission is likely to be rechristened to avoid confusion.
The significant unknowns at this point include the cost of the mission and the number and type of payloads it will carry. The Chandrayaan 2 mission cost the Government of India a little over Rs 600 crore (excluding the launch cost of Rs 375 crore for the GSLV Mk III rocket). The entire mission stack comprised 13 instruments: eight on the orbiter, three on the lander and two on the rover. When the surface mission failed, the following instruments (first three on the lander and last two on the rover) were lost, so a similar set of instruments will likely take their place assuming the mission profile and objectives don’t change.
* Radio Anatomy of Moon Bound Hypersensitive Ionosphere and Atmosphere (RAMBHA), a Langmuir probe
* Chandra’s Surface Thermo-physical Experiment (ChaSTE)
* Instrument for Lunar Seismic Activity (ILSA)
* Alpha Particle X-ray Spectrometer (APXS)
* Laser Induced Breakdown Spectroscope (LIBS)
Another issue is whether work on Chandrayaan 3 will further delay other missions, such as the Aditya L1 probe to study the Sun and the Gaganyaan human spaceflight mission. This outcome is likely if the past is anything to go by, when significant projects have diverted focus away from others, precipitating delays that have a cascade effect.