Ex-ISRO Chief Madhavan Nair On Chandrayaan-3, Chandrayaan-2 Failure & More

With its eyes set on becoming a major space power, India on Friday successfully launched its third moon mission, this time a far more complicated 41-day voyage to reach the lunar south pole where no other nation has gone before.

If the estimated Rs 600 crore Chandrayaan-3 mission of the Indian Space Research Organisation(ISRO) succeeds in landing a robotic lunar rover in the space agency's second attempt in four years, India will become the fourth country to master the technology of soft-landing on the moon's surface after the US, China and the former Soviet Union.

As the ISRO launched its third lunar mission Chandrayaan 3 on board the heavy-lift LVM3-M4 rocket from Sriharikota in Andhra Pradesh, former ISRO chief G Madhavan Nair spoke to Oneindia about India's latest mission. Here are the excerpts from the interview:

How do you feel about the launch?

Chandryaan 3 is a very important mission in the progression of India's space history. As you know, we had Chandryaan 2 about four years back. There was an attempt to land on the surface of the moon. Unfortunately, there was a last-minute glitch and about two km above the surface the spacecraft had dropped down and we lost the experiment. All the possible reasons for failure have been identified. The ISRO has toiled day and night for several years and corrected the landing mechanism. Everything is done to the best of the ability of the ISRO scientists. The lift-off was fantastic and the journey has started.

What should be the next crucial phase we should be looking out for?

Every day it will be going to be eventful. It is 36,000 km above the Earth's surface. The orbit has to rise, firing the propulsion, calibration of trajectory and all those things are there. Maybe on the fifth or sixth day we will be launching towards the moon.

Once it leaves the earth's gravitational feel it will be travelling in outer space with a high velocity and it is shaped to go near the moon. As it approaches the moon, the controls have to be effectively implemented so that the moon captures the entire module and put the orbit around the moon. And a lot of calibration and communication experiments will be done. And maybe on August 23, the soft landing operations will be initiated. There actually the lander will be detached and rocket motors will be fired in such a way it will be landing towards the moon. But this operation is very complex.

Can you please explain what went wrong last time in Chandryaan 2?

A number of factors could have contributed to the crash landing of Chandryaan 2. The configuration had lots of disturbances and the algorithm, the software developed for Chandryaan was not adequate to handle such deviation. There could be multiple reasons put together. So what I understand is that the ISRO has done a thorough job. They revisited every hardware, every software, and also redundancy management. In case if anything does not work properly, how to see a parallel system is initiated to ensure the final success of the mission. There is a reasonably good expectation that this mission will be 100 per cent successful.

Current ISRO Chief S Somnath has said Chandrayaan 3's approach is based on failure-based design. Can you please elaborate to us what exactly it means?

I have not heard his statement fully. In the previous mission itself, there was a rise in the orbit, going to the moon, and having the orbiter around the orbiter is still functioning. The operation until about 2 km above the surface of the moon was perfect. To that extent, the last mission was maybe 90 or 95 per cent successful. The entire event starting from today onwards is very critical and every step has to go perfectly alright. Then we have the final goal achieved.

What are the experiments that will be conducted on the lunar surface?

Rover will land there and the lander also has got a certain set of instruments. They will be looking for seismic activities on the lunar surface. And also the trace gases which are around. The rover will move around collect samples, do the chemical analysis and send the results. And also the temperature profile of the surface as well as the site below the surface. Again look for the presence of water. This will be going to be an exploration which will be lasting for 15 days.

The data gathered from the experiments, how do you think affect the Indian scientific community?
This data is valuable for the scientific community from numerous aspects. One thing is it is going to be a southern pole where of course earlier itself we have confirmed that there is water. The second thing is this region lacks heavy solar radiation. The origin of the moon, the planet, etc. and a lot of inputs we may be able to gather out of this mission.

What are the chances of success?

Once we do proper engineering and thorough testing, the chances of success are high. I believe this mission will be 100 per cent successful.