In a few days from now, India may take its first and longest planetary leap to circle and peer at Mars, and join a premier club habited only by Russia, the U.S. and Europe. K. Radhakrishnan, chairman of the Indian Space Research Organisation (ISRO), highlights the significance of the Mars Orbiter Mission and the trials of its short conception in an interview with The Hindu.
Does India need a Mars mission at all? At Rs. 450 crore, it has been criticised by some as a wasteful, rushed, "me-too" venture. Your predecessor G. Madhavan Nair has faulted it for its using the smaller PSLV launcher, for the scope of its experiments and even for the orbit around Mars, among others.
The Moon, Mars and the Sun were part of our country’s long-term space vision as laid out by the Advisory Committee on Space Sciences. Scientifically and technologically, we cannot afford to miss such missions. We have a three-pronged space programme, of satellites, launch vehicles and scientific and planetary explorations in that order, all of which are equally important. Like the fingers on your hand, you need them all.
If you look at the overall priorities and expenditure of the Indian space programme, our thrust areas of societal applications through communication, remote-sensing and navigation satellites have all been given due consideration.
The Mars Orbiter Mission is part of [the third priority of] scientific and planetary exploration, along with Chandrayaan, Astrosat, etc.
In the overall ISRO annual budget, 55 per cent is for satellites; 35 per cent is for launch vehicle development; 7-8 per cent goes into scientific and planetary exploration. The Mars mission is part of science and planetary exploration, along with Chandrayaan, Astrosat, etc. The 7 per cent is for enriching our knowledge about the Solar System. Such scientific missions pose very tough challenges to technologists. Some of the outcomes, for example the in-built autonomy we are providing in this spacecraft, can become a reality as a product or system and be used in satellites to improve their efficiency.
So they percolate to application, which is our main objective. It could be something like forecasting cyclones. There is always relevance for a mission such as this.
Cost-wise, how does the Indian mission compare with others?
One has to look at the overall context of benefits. In a national context ISRO’s budget is 0.34 per cent of the overall national budget. Internationally too, it’s a small budget. As Mars missions go, this is a low-cost one. Probably the others would be five times costlier because of the higher engineering costs outside India.
Why did you not wait and launch it after the bigger GSLV rocket was ready?
Whatever instruments were possible in the two years we had have been accommodated. The GSLV would have been an advantage in the initial phase, otherwise it was not an important item. The PSLV-XL has proven reliability and will do the job.
What should the Mars outing mean for the country, the scientist, youth and the commoner?
Any mission to Mars has numerous complexities and we at ISRO are doing it for the first time. If we look at the history of older missions of the U.S. or Russia, the success rate has gone up but is still around 40 per cent because of early failures.
For a technologist this is a challenge; for a scientist an opportunity to learn about Mars, which is an object of global interest. For the common man or student, it is a matter of pride that our country can do such a complex mission.
85 per cent of the mission objectives are achieved if we are able to orbit the spacecraft around Mars. Starting with 30 ideas, we will be doing five scientific experiments. The methane sensor is important; the thermal infra-red sensor traces the methane origin. Two more instruments will understand the escape processes of hydrogen/deuterium; and a Mars Colour Camera to get information about that surface.
What were ISRO’s main challenges?
All aspects of the mission have been daunting — from the time available to the new technologies and improvements we made for propulsion, navigation, tackling the 40-minute communication delay from Mars, readying the ground segment and meeting the critical timing of November 30. That is the D-day after the launch; by then it must leave the Earth’s sphere of influence. If you miss this opportunity you miss it for another 26 months.
Could you elaborate how were they met?
If you compare this mission with the Chandrayaan-1 which we did in 2008-09, there are several commonalities, but there are new challenges here. Both have the PSLV rocket and an elliptical orbit for the spacecraft. In this case you have what we call the ‘argument of perigee’ of about 270 degrees which requires a longer flight and a different trajectory. It is to use minimum energy or fuel to transfer it from an Earth orbit to a Martian orbit. That is also why we need the two ship-borne terminals.
On the ground station we enhanced a 2 KW power system in the 32-metre antenna in our Deep Space Network to 20 KW. We introduced a new system for precise ranging of the orbiter.
The orbiter was built to bear totally different temperatures and do many tasks by itself. Mars is some 400 million km away and the mission will have a communication delay of 20 minutes each way with Earth. Rather than send a chain of commands from here to check its health and to correct a problem, we stored them in the system itself.
We can still trigger them. During the 300 days of its transit, if the spacecraft develops a serious problem, it has to be put into a safe mode so that the ground controllers can set it right. The spacecraft propulsion system must be put into sleep during the journey and reactivated after 300 days.
We made new navigation software to know the exact position during the trans-Mars injection and also estimate the influence of other planets and Sun.
What is the nature of support that NASA is providing?
The spacecraft must be continuously tracked and must be visible at all times. We largely use our own ground station at Byalalu near Bangalore. For some phases of the mission, until the spacecraft is put into the Martian orbit, we are taking the support of NASA’s Jet Propulsion Lab’s Deep Space Network and its three international ground stations.
Over the 300-day travel, what contingency or safety mechanisms have been provided?
Contingency plans are part of all our satellite missions and they have to be much more elaborate than those in a planetary mission. Plans B, C, D, E and F are all documented, tested and kept handy. Everyone on the job knows what to do if something does not go right.
What after Mars?
For now it has been the Moon, Mars and the Sun on our plan. Scientists at our Physical Research Laboratory are looking at the Universe itself. For the next mission, we should look at larger scientific objectives with more partners but that depends on how we progress on this mission. There is the all-Indian Chandrayaan-2 with a lander and a rover and launch on the GSLV, hopefully by 2016.
Are you looking at joint missions?
Joint missions hold a lot of potential. We have excellent relationships with several space agencies. When NASA’s Chairman visited ISRO recently we spoke of possible asteroid studies but that is a distant dream. When we have some capabilities there will be people wanting to join us. We work with the strengths of different teams, as SARAL and Megha-Tropiques have taught us.
In the immediate future, we will work [with NASA] to develop a complex satellite with dual frequency radar systems which is planned for 2019-20. The two teams are writing the project reports together – the S-band radar by ISRO and the L-band radar by NASA/JPL. The satellite will be built and launched by ISRO.