`In space, we do not take risks'

Interview with R.V. Perumal, Mission Director, GSLV.

After the success of the GSLV-D2 mission, the toast of the Indian Space Research Organisation (ISRO) was Mission Director Ramanujam Varatharaja Perumal. He was the deputy project director of ISRO's Polar Satellite Launch Vehicle (PSLV) programme, which has had six successes in a row. He was responsible for the flight integration and launch operations of the first three PSLV flights. From 1996 to 2001, he was Project Director of the Geo-Synchronous Launch Vehicle Programme (GSLV) and in charge of its overall technical and financial management. From May 2001 he has been the Associate Director (Projects), Vikram Sarabhai Space Centre (VSSC), Thiruvananthapuram.

In an interview to T.S. Subramanian after the launch, he spoke about the ambitious GSLV-Mark III, of sending capsules into space, developing an indigenous cryogenic engine and so on. Excerpts:

How do you assess the success of the GSLV-D mission?

This is our third GTO mission. This is the first time we have achieved the precise transfer orbit. So it becomes a totally successful mission. We are all happy that we could properly do the mission planning this time, taking into account the capability of the GSLV based on the lessons we learnt in terms of performance characteristics of the various systems of the earlier missions.

In addition, the payload was heavier this time by 300 kg. So from all angles, we took a calculated development effort and we achieved it.

Can we say that you took a calculated risk?

In space, we don't take risks. Space is really unforgiving. It is not like an aircraft where a pilot takes charge and does something. In space, everything has to be estimated and planned precisely. Only our imagination is the limit. And we should be able to imagine precisely so that we can do the correct thing.

What will be the improvements in the coming GSLV flights?

Basically we are talking of further reduction of mass in its various stages. For example, if you take the equipment bay (which is the "brain" of the vehicle, with its electronic equipment), we need to improve further the mass because any mass saved will be converted into higher payload capability. We will use advanced instrumentation, advanced electronics, and so on. We will also take into account the performance of the various systems in the second flight and will try to derive maximum benefits by characterising them. As our Chairman (Dr. K. Kasturirangan) said, our goal will be to put a 2,000-kg satellite into orbit with the GSLV. We can launch anything up to 2,000 kg with this GSLV. For anything beyond that, we will have to go abroad.

In this mission we were conservative because we did not achieve the goal in the first flight. We wanted to be sure that we had a more conservative approach so that we can hit the bull's eye. We have taken the view that if the first two flights of the GSLV with the Russian cryogenic engines are successful, we will have an operational GSLV with the Russian cryogenic engine in the third flight.

So the next GSLV flight is an operational flight.

Yes. Parallel, we are developing our own cryogenic stage. As and when it is ready, we will launch the third developmental flight of the GSLV (the fourth flight of the vehicle) with our own cryogenic engine and prove the indigenous cryogenic stage in flight.

Can you talk about the GSLV-Mark III? It seems to be shorter in height than the present version but have the capability to launch a four-tonne spacecraft in GTO or a 10-tonne satellite in low earth orbit (LEO).

We had a goal. We originally estimated that 2,000 kg class of satellites are what we will be launching. However, our requirements have grown out of our own projections. We are now talking of 4,000 kg class of satellites. In order to put four-tonne class of satellites into orbit, this vehicle has to be practically double the size. So that is what we intend to do in developing a GSLV-Mark III to reach four-tonne class of capability in the GTO. That vehicle will use our proven technologies in the area of solid propulsion, by developing a new booster with 200 tonnes of propellants.

Will it be the core stage?

No. It will be Strap-on boosters. And the GSLV-Mark III will have a core liquid stage with more than 110 tonnes of propellants. We will also develop a heavier cryogenic stage, with something like 25 tonnes of propellant loading of liquid oxygen and liquid hydrogen. All this will together meet the need to put the four-tonne class of satellites in GTO.

What is the Space Capsule Recovery Experiment about?

It is like recovering a satellite. We are going to put a space capsule in orbit to carry out certain experiments in micro-gravity, material science, pharmaceuticals and so on. The space capsule is a kind of low-cost platform for carrying out experiments in space, unlike having a shuttle; or going to the International Space Station or the Mir Space Station. Instead of these, you launch a capsule in which experiments are done. The capsule comes back to earth, you recover it and see the results.

Will the PSLV launch it?

Yes. This class of capsules will be launched by the PSLV. We will be doing this by 2005. Developing the capsule and flying it will cost Rs.50 crores. The research and development is in conceptual stage now. First we have a project to fly one or two experiments. If we find them useful we will master the technology and if the experiments that scientists come up with are worthwhile, we can repeat the flights.

Will the capsules be recovered from sea or land?

Right now our plan is to have a sea recovery after a parachute landing.

The first flight of Ariane-5 was a failure. The second flight also failed to deliver a communications satellite into the correct orbit. Still, Arianespace declared the third flight of Ariane-5 operational. In comparison, how do you feel about the successes of the GSLV and the six successful flights of the PSLV?

(Laughs). We are professionals. We do a professional job. We had two failures in the ASLV (Augmented Satellite Launch Vehicle). We had one failure in launching the PSLV. These were very important failures in the sense that they taught us a lot of things - how to make a proper launch vehicle, how to provide the design, what are the margins within which we should operate, and so on. The failures also provided lessons on how we should qualify software. These are lessons that we are faithfully sticking to and applying. We tested, re-tested and re-tested. So we learnt these lessons in the last ten years and we made improvements based on these lessons. We stick to them very religiously even now. Our success goes to that.