A month has passed since Vikram lander lost contact seconds before Moon landing. Retired Isro scientist S Nambi Narayanan, who was the chief architect of the Vikas engine that powered launch vehicles which carried Chandrayaan 1 and 2, talks to U Tejonmayam about what Isro needs to do to make its future deep space missions successful:

After a nearly six-week voyage to moon, Isro lost contact with its lander Vikram during touchdown. How big was this setback?

The only difference between Chandrayaan-1 and Chandrayaan-2 was the soft landing on lunar surface. If you look at it that way, Chandrayaan-2 is a failure and it’s certainly a setback for Isro. However, it’s not so huge that future missions will be affected. But saying that the mission is 98% successful is like giving only 2% to the soft landing part of the mission, which is not logical.

What could have gone wrong with Vikram during the descent phase?

Vikram could have crash landed after losing contact. This shows that it had an orientation problem. It could have tumbled with the antenna facing in the wrong direction. Isro would have known this, had they done enough simulations to look at possible failure modes. In Isro, we do thousands of simulations for possible situations even if they are crazy. Simulations can be complex, tough, monotonous and boring, but critical. In Vikram’s case, these seems to have been lacking. This observation will come out when the failure analysis committee submits a report. Another reason could be use of existing small thrusters as retro rocket. I don’t think Isro developed a new thruster. That could also be why four or five thrusters were used. A single thruster could have been easier to control.

What should Isro do now?

It’s time that Isro plans and makes an integrated outer space progamme definition document with the help of an eminent national committee. The document should clearly state Isro’s objectives, how it plans to execute the missions and what these will achieve. Isro’s satellite programme is fairly good. But in deep space programmes like Chandrayaan, Mangalyaan and Aditya, we don’t seem to have a definition document so far. Mangalyaan was a technology demonstration and Chandrayaan could have been out of curiosity, but we cannot go on like that in the future. When the missions are defined, Isro will also know the new technologies it may need to develop.

What about Gaganyaan? Isro plans to send a man to space in 2021.

Gaganyaan is an interesting programme, but seems to have no definition document. On what basis is Isro saying it will have first Gaganyaan mission in 2021? The launch vehicles first have to be man-rated. For human spaceflight, there are a lot of technological challenges to be addressed. Isro should have a life support system comprising a team of doctors, which will address the issues of the astronauts when in space, the effects of zero gravity, isolation and psychological impact.

Apart from interplanetary missions, should Isro focus on developing new rockets and engine to enhance its launch capabilities?

Isro has Vikas engine, S200 solid boosters and cryogenic engine. After the first successful flight of PSLV in 1993, which used Vikas engine, we have not developed any liquid engines in the last 26 years. Isro’s attention should now be to develop a launcher and engines for both immediate use and for the future. I would suggest a LOx methane thruster similar to Raptor made by SpaceX. It’s an interesting concept and has a high specific impulse of about 330 or 350. China is also silently developing something similar. Isro should develop a super engine in the range of 200 tons thrust. It’s not easy and it may take three to five years. The LOx kerosene powered semi-cryogenic engine bought from Russia could also be tested, though kerosene’s performance is highly questionable. Isro will know it needs these technologies only if it defines its deep space missions.

What should Isro do to keep pace with the space race?

Isro should go ahead with its future missions. But if it wants to become a force to reckon with, it should take the initiative in establishing an Asian Space Agency (ASA) like the European Space Agency or NASA. A national committee should be formed to work on it with the support of external affairs ministry and our diplomatic missions abroad. If we can set up ASA, we can join ESA and NASA and together conquer space.

My other suggestion for Isro would be to make Sriharikota a separate organisation. It can set up a new launch complex in Sriharikota with funds from countries like Russia and China. For them the launch location will give a payload gain and save cost and for us, it can be a tradeoff to make China join ASA. The launch pad planned in south Tamil Nadu will also give payload advantage. These launch pads can be used for ASA launches as well. Satellite and launch vehicle centres could also be separated and Isro can be an apex body controlling all of them.