BENGALURU: India, whose lunar ambitions have been more clearly articulated now than a decade ago, is firing on all engines with the National Space Commission, the apex body that decides on space missions, clearing the fifth lunar mission — the Lunar Polar Exploration Mission or Lupex.
Unlike missions Chandrayaan 1 to 4, this will be jointly implemented by India and Japan, but is part of India’s lunar series that eventually aims to send an Indian to the Moon and bring her/him back.The Union cabinet cleared Chandrayaan-4 on Sept 18, and Lupex will be put up for cabinet clearance soon, although the space commission nod gives Isro the go-ahead to work on the mission.
“We wanted some more approvals [from cabinet] to happen. Possibly, in the coming days, they will also get approved… We have to have a series of Chandrayaan missions which will build up the capability from the current level to the one which will actually send humans to land on the Moon and bring them back,” Isro chairman S Somanath told TOI in an exclusive interview.
Lupex is a mission aimed at exploring the Moon for water and other resources and gaining expertise in exploring the surface of the Moon.
Long-term lunar vision
“At present, it is at the technical discussion level. Commitment from the Japanese side is known. They have assigned the development of the rover to a firm. Also, their govt has allocated money for the project and they’ve identified their launcher for it,” he said. Although Isro and Japanese space agency Jaxa signed an agreement in 2017, one of the challenges that prevented work on Lupex after India’s Chandrayaan-2 mission — as was the initial plan — was the inability to demonstrate soft-landing of the lander on the lunar surface.
“…So, we took it up after Chandrayaan-3 soft-landing. We found that the configuration of Lupex spacecraft needed total re-engineering. And, it should also align with the long-term vision of our Moon programme. It cannot be just a replication of whatever we’ve done, but it should add features, which would ultimately become useful for human landing,” Somanath said.

Engine for human landing
He added that Isro has completed re-engineering the spacecraft, which called for the development of a new lander engine. “This engine will ultimately be used for human landing on the Moon. That engine, being built by LPSC (Liquid Propulsion Systems Centre), will be part of Lupex, which means we will have the capability early,” he said.
“…The lander is heavier (compared to the initial design) and the rover is also 350kg. Now, how will the rover be taken out of the lander and put on the surface? Such a big rover cannot be carried inside the lander as we did with Chandrayaan-3, we have to mount it externally. Once you’ve done that, how do you remove it and place it on the floor (of the Moon)? We are looking at a sky-crane type of arrangement to do this. All of this was done in the last one year — the relook at the architecture and design,” Somanath said.
Chandrayaan-5?
TOI had reported last year that Lupex would require a more powerful lander engine as the lander size was not comparable with Chandrayaan-3. On the timeline for Lupex, Somanath said: “Both (Chandrayaan-4 and Lupex) should happen parallel to each other. Possibly Chandrayaan-5 should happen soon after Chandrayaan-4, there cannot be much delay. It won’t be that work on Chandrayaan-5 will begin after Chandrayaan-4.”
On whether Lupex has been designated Chandrayaan-5, he said: “We would like to call it Chandrayaan-5 but that will require approvals. We will seek further approvals to fit it under the Chandrayaan series, which will have missions beyond Chandrayaan-5 — we’re looking at what technologies we would need so as to reach the human landing stage.”