In this Walk the Talk on NDTV 24×7 with The Indian Express Editor-in-Chief Shekhar Gupta, ISRO Chairman K Radhakrishnan speaks about the indigenous cryogenic engine that launched GSLV-D5 and why the Mars Orbiter Mission is crucial for India.
I’m at Antariksh Bhavan in Bangalore, the headquarters of the Indian Space Research Organisation (ISRO), where you see many smiles wherever you go and nobody is smiling more happily than its Chairman Dr K Radhakrishnan. One can’t find a space scientist with a more diverse portfolio — the Mars mission, the lunar mission, GSLV and then your own Tsunami Warning Centre, and the 24×7 Disaster Management Centre. You are a man of many parts.
The Indian space programme is people-centric and application-centric. That’s our USP, that whatever we do, it should finally find a place for the common man.
And you have had about eight launches in seven months?
Yes, since July 2013, we have had eight successful missions — PSLVs, a few satellites, the Mars Orbiter Mission and the latest GSLV-D5 with the Indian cryogenic engine and stage.
Teach us some rocket science… explain to people who can’t tell the difference between geostationary and polar.
Essentially, when we talk about a satellite doing remote-sensing, it has to go above the Earth from pole to pole. As the Earth rotates, and the satellite goes from pole to pole, the cameras in the satellite would be able to see the entire Earth. It can take pictures, as and when you require or periodically. In the case of communication satellites, what we do is put a satellite at an altitude of 36,000 km above the equator. The satellite would take 24 hours for one revolution, which is equal to what it takes for the Earth too (to rotate on its axis). So the satellite would be geostationary, that is, a stationary object with respect to us on the Earth. So these are the two things we generally talk about. The Polar Satellite Launch Vehicle can launch remote-sensing satellites, satellites for space science experiments, satellites for communication, it has also launched Chandrayaan and the Mars Orbiter. So in the PSLV family, we have three vehicles. Now, GSLV is a more powerful vehicle. The core stage of PSLV is used in GSLV too. The second stage of PSLV is adapted and used in GSLV.
More or less replicated?
Yes, and here you will see large strap-ons, liquid engine-based strap-ons.
And I believe each one of them carries 200 tonnes of fuel?
Each of them carries 40 tonnes and the core has 139 tonnes of solid propellant. But the most important and crucial element of GSLV is the cryogenic upper stage and that’s what we tested successfully.
Sir, now that I am getting my tutorial on rocket science, tell us the meaning of cryogenic. I know ‘cryo’ is something that is cold.
There are three varieties of propulsion used for rockets. One is the solid propellant base. That means you have got the solid fuel and the solid oxidiser, plus a few additives. This can be used in the lower stages of the vehicle. It’s easy to handle once you prepare it. But when you talk about the liquid engine, there is an oxidiser and fuel. The fuel can be kerosene or liquid hydrogen. When it is liquid hydrogen, we call it cryogenic.
And now you go on to your next GSLV.
If you look at GSLV Mark III, which we are now developing, it is far more powerful compared to GSLV. In GSLV, we can put a 2,200 kg satellite into a geostationary transfer orbit — that means in an orbit where the apogee is 36,000 km and perigee is 200 km — whereas in GSLV Mark III, we can take to the orbit a satellite of 4,000 kg. So that’s almost double the capacity.
Sir, if you can explain perigee and apogee…
Perigee means the distance closest to the Earth and apogee is the farthest point.
So, as it goes into elliptical orbit around the Earth, sometimes it will be closer, sometimes it will be farther?
Exactly. So using the propulsion system in the satellite, we move it into a 36,000 km circular orbit and take it to a place above the equator.
So when are you planning this launch, the next landmark?
The first landmark is an experimental mission where we will look at the atmospheric phase of this flight and we will use a passive ignition stage, in the sense that it won’t ignite. But all the lower stages will perform and we will monitor the performance of this vehicle in the crucial atmospheric phase. This is going to happen by April 2014.
By testing out its response to atmospheric conditions, you mean that in the first 30-40 km, it will face winds and pressures which don’t exist in outer space?
So when do you expect the full launch of this?
The full launch should be possible by 2016-17. What we have done now is testing of the engine. Some of the stage components have also been tested. So for the next two years, we will go through a qualification programme for the engine as well as the stage. Once it is completed, then we will be able to release this vehicle.
Then we can launch much bigger satellites for which we today have to go overseas?
We will be able to launch communication satellites weighing about 3,500 kg to 4,000 kg. Today we do it through Ariane-5 rockets.
So, what happened in the past? Why has GSLV given us such trouble?
There are two reasons. GSLV, of course, is a beautiful vehicle and a simpler vehicle, except for the complex cryogenic stage. GSLV derives its heritage from the sub-systems of PSLV, in terms of the solid core stage and the liquid strap-ons and the second stage. It uses liquid propulsion where we need to get a lot of controlled components. During the flight or during the preparation phase, it can leak a little bit. The second part is incidental — in the first GSLV flight that was done in 2001, one of the strap-ons did not ignite, it did not get the fuel. But there was an inbuilt system for aborting the flight… that worked beautifully and the flight was aborted. Within 22 days — it was a record — our people brought it back to the launch pad.
And the whole thing was saved?
Yes. But the satellite did not stay there for more than two months because the Russian cryogenic stage at that time did not perform to its required level. It was underperformance of that stage but nevertheless it is a first developmental flight of GSLV and a very crucial milestone for the country. The second and third flights of GSLV worked very well. It launched GSAT2 and GSAT3, what you call Edusat. In the GSLV flight that we did in 2006, one of the components in a strap-on did not perform properly. That means the vehicle had to go with only three strap-ons. It was a failure. The next flight that we undertook in 2007, the control system of one of the strap-ons failed. However, the vehicle was able to put the satellite into an orbit very close to where we wanted it. And then the satellite propulsion system was used to take the satellite, INSAT-4CR, into the right place. So nothing was basically wrong with GSLV but component failure resulted in these few failures. In 2010, we had two flights. The first one was to test our Indian cryogenic engine and stage. Here too the vehicle beautifully performed up to the end of the second stage. The cryo stage ignited and we were very happy at that time. But immediately after that, a fuel booster turbo pump stopped.
Why did that happen?
We investigated and found there are three possibilities. One, of course, is contamination. It is sitting in a liquid hydrogen tank. It is at very low temperature and…
It is 20 Kelvin or -253°C. There are dissimilar materials used in the pump and the contractions will not be uniform. We also had a possibility of a casing of the pump coming out, so these two had to be corrected. But later we found out that the most probable cause was contamination from a propellant acquisition system kept in the liquid hydrogen tank. So we replaced that, redesigned it and got a new one. We also tested this pump extensively in this low temperature condition and ensured that it works. The second part of it was, had this pump worked, are we sure that the rest of the functions would take place? We did a lot of analysis and simulation. And one thing we wanted to make sure before we took off again was to see that this cryogenic engine ignites and we are sure about it at this high altitude condition where there is vacuum. We had not tested this in the past on the ground. So we created a test facility at Mahendragiri (Tamil Nadu) and then we tested it and saw to it that we are confident about it.
So that’s why this launch with an Indian cryogenic engine is such a landmark?
It’s three years of work, during which we did 45 tests on the ground on the cryogenic engine and stage. Also, why did the GSLV configuration fail? Is there something fundamentally wrong it? We did nearly 850 wind tunnel tests.
But now you don’t have that doubt?
Now, we don’t have that doubt.
So we can take the view that your successful GSLV with your own cryogenic engine is an even bigger landmark than the Mars Mission, which was ahead of the lunar mission.
Both are landmarks. One, in terms of technology, cryogenic technology is complex and we have done it.
It greatly increases your range and payload.
Yes, and the capability of India to launch heavier satellites has now been established. The Mars Orbiter Mission is critical for space exploration. It also shows India’s capability to take a spacecraft to a distance of 400 million km, control it properly there and then conduct experiments
But sir, there is also scepticism. After so many rovers, so many landers, what will this bring back?
The objective of this mission is to prove our technological capability to precisely orbit a satellite around Mars. There have been 51 Mars missions; only 21 were successful. Secondly, the scientific objective is to study the presence of methane. Why is methane important? We want to understand the existence of life on Mars.
Could we find something that has not already been explored, given so many missions that have been successful?
The presence of methane or otherwise, and the origin of that, whether it is geological or biological, that is something that this mission is going to look at. Also, the atmospheric processes on Mars…
Well, the remarkable thing is the cost of the mission.
Cost and time, both. We have done it at 1/10th the cost.
There is one more reason why this cryogenic is important. Because I was a sort of a participant in the tamasha that went on more than two decades earlier, of how this programme got a setback (the spy scandal). I used to then work for India Today and I had done a story saying these allegations of spying were wrong. Have you reflected very much on that? Was it a setback to ISRO?
The programme goes on. We have come out of all those and today we have the technology with us.
What is it that makes ISRO different? Somehow, ISRO manages to do more tangible work than most other government organisations.
When we conceive a programme, we look at how it is going to be useful for people, how to reach it to people and how to build systems so that it becomes part of the value chain of those people.
But you also have a better industry interface.
Yes, we had decided from the seventies that Indian industries, both public and private, are going to be part of us. We also make the best use of the academic community in doing research activities.
You got your MBA from IIM-Bangalore before you got your PhD from IIT-Kharagpur.
So you are a businessman as well as a scientist. What made you go for an MBA before you went to research?
Because of the uncertainty involved in high-technology programmes like space, they had to use several of these management techniques.
But your commercial arm Antrix has been struggling a little bit?
If you look at the turnover of Antrix, it has been going up. We recently launched a SPOT 6 satellite, one of the best remote sensing satellites in the world, and SPOT 7 is ready to be launched.
I know remote-sensing is your own special field of interest.
That’s true. Antrix has been contributing a lot to the communication satellite programme. A number of satellites of foreign countries are lined up for launch using our PSLV. The recently launched microwave remote sensing satellite… is also going to be used by foreign customers through an arrangement with Antrix.
But Antrix also got an undue share of controversy for getting into an arrangement with a private company. Two things appeared, one the word ‘spectrum’; second, the word ‘private company’. And somebody even put a figure of Rs 2 lakh crore, because we can’t settle for less than that for a scandal now.
Yes, much has been talked and written about this subject. Over the last three-and-a-half years, we have done what is best for the country, what is best for the government of India, what is best for research.
Was the controversy avoidable? Because there was no scandal.
I don’t want to get into the merit of it because it is going through a legal process at the moment. But what has been done is best for the country.
You have done the damage control?
Kiran Karnik was on this show and he said that having seen so much of the government of India, so much of India, he has never found another Indian organisation with a commitment and integrity to match ISRO’s, which is a high compliment.
Thank you. We have done what we thought and what we think is best for the country.
And you have a track record to deserve the highest of compliments. Dr Radhakrishnan, thank you very much. I know you have many more frontiers to climb and they wait— one in April and one in a couple of years from now. And towards the end of this year, you put your Mars Orbiter in space.
September 24, 2014 is a crucial day for the Mars Orbiter, when we have to precisely reduce the velocity of the spacecraft and make it orbit. If we miss that, then we lose the mission. But we are hopeful.
I am sure you will take no chances. Because one thing that intrigues me all the time is how religious many of your scientists are — you find coconuts being broken, pujas, mantras…
We are all Indians…
So, science or no science… you see no contradiction?
We don’t see any contradiction.
Transcribed by Sonam Chauhan
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