New Delhi:
Chairman of the Indian Space Research Organisation Dr G Madhavan Nair speaks to NDTV about Chandrayaan Mission.
Pallava Bagla: What has been the performance of Chandrayaan mission till now?
G Madhavan Nair: We are extremely happy with the Chandrayaan mission. As you know in November last year we took to the moon and since then we have been operating systematically.
Pallava Bagla: So would be it ok to say that you have had a dream run till now?
G Madhavan Nair: Yes, I will say as far as the mission objectives are concerned, it has been a 100 per cent success. We have achieved whatever we set to achieve through this and so far the performance I think has been to the full satisfaction of our scientific community.
Pallava Bagla: I believe something has malfunctioned, some critical malfunction has happened on the Chandrayaan-1; what has really happened?
G Madhavan Nair: You know the space missions - they are very complex. There are instances of problems on board and we are also not spared from this. But as you know that normally we provide for redundancies on board and that is supposed to take care of, in case of a problem. The first thing what we had encountered was when it was put in the 100 kilometre orbit. It simply reached the stage of thermal runaway. The entire spacecraft would have been baked and would have been simply lost.
Pallava Bagla: Baked and lost!
G Madhavan Nair: That was the scenario one month after the launch. But fortunately our mission team - they worked out a strategy by which it was oriented in the right direction and also the thermal management by putting off some of the instruments which are not vital and then looking away into the deep space - with that we have managed and since then we have really run the instruments according to what we wanted.
Pallava Bagla: So, for a layman would it be ok to say that the spacecraft was overheating?
G Madhavan Nair: Yes, it had reached a stage where many of the electronics would have failed. Yes indeed some of the power supply related instruments failed but fortunately we were able to energise the redundant units and keep it alive all this time. And of course this has been going on for quite sometime but unfortunately during the last month we have lost one vital sensor - the star sensor. Like in old days you looked at stars to fix the direction. So we have an onboard electronic instrument which is doing this and this was required for precise pointing. With the loss of that we were really worried and normally the mission could be lost but to the credit of the ISRO scientific team, they have worked out a very innovative way of overcoming this. In fact you know there are cameras on board on Chandrayaan that are looking at the moon and there are known spots on the moon which are well defined. Similarly the Chandrayaan is looking at a ground station at Bylalu. So that's also a fixed location. Using this vector they have evolved a mathematical formulation by which we were able to recapture the orientation and using the onboard gyros which are supposed to be, you know, the redundant pieces, we were able to run the mission as satisfactorily as earlier. So I can say that these two events which would simply have led to a mission catastrophe were managed by ISRO's team very efficiently.
Pallava Bagla: So in a layman's term, would it be ok to say that the satellite is orbiting the moon but you were not able to locate specific things on the moon, through the loss of the star sensor?
G Madhavan Nair: If we did not have a redundant system we would have lost. Even the gyroscope which is there, it has limitation. You know what happens is it has got a drift with time. So there, the innovation of our scientists came in and within a very short span of time they have formulated, validated the software and conducted sufficient experiment. Today it is able to precisely point to the lunar location as with the star sensor, so we are not compromising anything on board the spacecraft now.
Pallava Bagla: So you had a failure but you have been able to recover from that?
G Madhavan Nair: Absolutely. This actually as I mentioned earlier, the space missions, we have to be anticipating some sort of a problem or another and normally we provide a certain amount of redundancies. When it goes beyond that, then the mission will get lost. There are instances in which many missions were lost in their early phases but I will say that we were lucky that we have completed almost all the mission objectives.
Pallava Bagla: So would this be called jugaad technology? Something failed and because you have learnt the art of maintaining these things you are able to put some innovative things together - would it be jugaad, would one say?
G Madhavan Nair: I would say that it is the imagination, the promptness of action and also the type of the solutions which we find - they are very unique. You know, we do not have to go through a situation where if something fails then we can go with another mission immediately; so we try to see that these missions are very carefully attended to and we do not leave anything to chance. Every spacecraft which is there, it is being monitored through our telemetry and tele-command system by a human process. Every spacecraft has a 24-hour watch kept by our people. And that also our senior people intervene at the right time, so they will find a right solution and the whole thing is managed by them.
Pallava Bagla: So right now, is the spacecraft working normally?
G Madhavan Nair: Well I can only quote a scientist. They have given 'n' number of action items or more to image or to collect the data etc. During this season, every request from the scientists has been serviced.
Pallava Bagla: So have there been any key findings from the machine till now?
G Madhavan Nair: Well one thing I can say - the features which are revealed by the terrain mapping camera is very unique and to this resolution of 10 metres is the first of its kind. Of course it has to be further analysed and codified and catalogued and all those exercises are going on. The terrain mapping which is done by the laser instrument is also very interesting data. One can really dig into the origins of the craters and so on. The mineral mapper - it has more or less looked at the entire surface of the moon and they were able to identify the locations where it is rich in iron-ore, where there are calcium deposits, magnesium deposits and even titanium, which is supposed to absorb the helium 3 - such locations have been seen. But again we have to really systematically code it - that exercise is going on.
Pallava Bagla: Are there any Indian instruments which will suffer completely because of this failure because I believe you have had to raise the orbit from 100 to 200 kms?
G Madhavan Nair: But that was done for an entirely different purpose. You know the primary objectives have been met at a 100 km orbit. Then you know every month we have to do a nudging operation to keep that orbit live. By any chance if any problem comes in that operation we may crash land on the moon. Since the primary objectives were completed we raised the orbit to nearly 200 kms - that is a stable orbit. Even if you do not apply correction it may vary about 20-30 kms but that is stable. Also there is another objective. We can try to analyse the perturbations of the gravitational field at this height. So that is another reason. But at the same time some of the instruments which we are having has a resolution of, let us say, 10 metres that will go to 20 metres but advantage is we will cover a larger area. So it is a trade off between the resolution area and cover. So I will not say that any instrument has suffered. But only one instrument we had, I will say, that had a slight handicap was the X-ray instrument - it depends on the radiation from the sun. Solar flares have to be there - that we cannot reproduce. So this happens to be the quietest period as far as the sun is concerned.
Pallava Bagla: So the sun is not getting angry?
G Madhavan Nair: Well, I think of late, some growling has taken place. So it is giving some signal, so we were able to pick up some signatures in the last few weeks.
Pallava Bagla: But what about the lunar laser ranging instrument? That was meant to function only at a 100 kilometre orbit. Will it be able to function at 200 kilometre? The new orbit which you have?
G Madhavan Nair: Well I think it will not give the same sensitivity. In the sensitivity - some suffering is there; but we are analysing the margins and hope we will be able to put it back again.
Pallava Bagla: So some data is expected from that also?
G Madhavan Nair: Yes, I think, see, we have the past pictures from the laser instrument, all this we are keeping live.
Pallava Bagla: And what about the Indian scientific team? Because there were 5 Indian instruments and 6 instruments from foreign countries? Is the Indian team happy with the data which they have? The scientific data?
G Madhavan Nair: First of all, with our instruments, the data is entirely coming to our teams. As for our arrangements with foreign scientists, I think they have already had their interactive sessions, they have shared some of the data and they are working on some of the analysis and publications on which I hope in the next few months some visibility will be there.
Pallava Bagla: So is there enough on board fuel for you to take the mission on for the nominal 2 year life?
G Madhavan Nair: No in fact fuel-wise we have no concern because initially the errors were so small we did not have to depend on reserves. So enough fuel is left and if it continues as it is, fuel will not be the limiting factor for the life. And we will be watching as long as the experimental objectives are met - which I know that more than 90 per cent objectives are already completed. The remaining ones also we will complete; after that whatever we will get will be a bonus.
Pallava Bagla: So are we already on bonus time?
G Madhavan Nair: Not exactly. But maybe one more season we will watch.
Pallava Bagla: Let me ask you specifically - with this loss of the star sensor for which there was no redundancy on the spacecraft, you said we have lost a little bit of the pointing accuracy but you have been able to come up with an innovative solution - will there be a compromise of some kind on the mission life?
G Madhavan Nair: Not at all. The life is not related to this, because life is only orbital decay. When it takes place we should be able to fire the rocket engines to trace it back. As I told you we have gone to a 200 km orbit; even whatever decay happens it will be between 180-200 kms. But still enough fuel is there.
Pallava Bagla: The big finding which was expected from Chandrayaan was whether there is water on the moon or not. Have you been able to find any signatures of water on the moon or water - ice to be more precise?
G Madhavan Nair: Well, I don't think I can confirm it today because the signatures are not that clear to say there is water. But still the scientists are hoping they can break through the data and look at the polar region where there is a small chance of finding water but maybe the next phase of experiment with the MiniSAR. They are actually as you know that the US spacecraft is already there, they have got a similar instrument.
Pallava Bagla: Oh! you are talking about Lunar Reconnaissance Orbiter?
G Madhavan Nair: Right. These two put together they are trying to plan some experiment which may give maybe a better quality signal. We are going to look at that.
Pallava Bagla: So we are looking at a jugalbandi between a NASA spacecraft and an ISRO spacecraft?
G Madhavan Nair: Something similar to that, actually one will radiate and another will pick up the signal and express that. So we are just in the discussion stage. If that comes through we may get slightly better quality signal, but today I cannot confirm the signature is sufficient to say there is water.
Pallava Bagla: So we have to wait?
G Madhavan Nair: Maybe a few months.
Pallava Bagla: Because finding water is key to colonizing the moon.
G Madhavan Nair: Yes, as you know there is no oxygen; it is absolutely essential for sustaining life and water also. So if water is there one can always lead to rather than is absolutely essential for sustaining a colony in moon.
Pallava Bagla: So one thing which always captures the imagination of the public is the human flight. I know you have a plan in place, which will cost about 12,500 crores. Has the government been supportive of that plan?
G Madhavan Nair: You have seen the last 2 years - the government has created like a pre project activities. This is a very complex project on which you should have clarity on the technical content of the job, the technologies to be developed, new materials to be developed and so on. So we have been in that mode, we have identified issues related to the developmental plan and this year also government has given nearly 230 crores for the initial work. And this will enable us to be prepared for taking up the major project for which already the project report is in place and we hope the government will be able to review and take an appropriate decision soon.
Pallava Bagla: So when are we hoping to get the big branch of money?
G Madhavan Nair: Well, as I told you already the pre project activity is funded. If I get the approval during this financial year, yes the project will be on as scheduled.
Pallava Bagla: So how many years from now can you undertake?
G Madhavan Nair: We are still holding onto the 2015 - for the first man flight around the earth.
Pallava Bagla: And what will that be like?
G Madhavan Nair: Two men in an Indian capsule...
Pallava Bagla: Not women?
G Madhavan Nair: Perhaps, sorry, I think I must correct ... we do not want a gender bias, it will either be a man or a woman from India and who could be trained in our facilities and they will travel to the space and back after a 7 day mission.
Pallava Bagla: On a 7 day mission? And this will be like a low Earth mission?
G Madhavan Nair: Yes and that will be done with an Indian Rocket System, GSLV.
Pallava Bagla: So Sriharikota would be the place?
G Madhavan Nair: Yes, we will be launching it from Sriharikota and the capsule will go to space and then come back.
Pallava Bagla: So how much of those technology generation still needs to be done? Are we in good shape on that?
G Madhavan Nair: Well, I think at least we know what needs to be done. But it is going to be really demanding. First of all to create a habitat which is conducive to human life in space - that is a tremendous thing - we have radiation, we have micro-g condition, there is no oxygen, no food supply and even the body behaves in a different manner. We have to understand the physiology conditions under the micro gravity conditions; so all this is a really tough job. Over and above we want to improve the reliability of the launch system. Today we have roughly about 10 per cent probability of failure. It is not acceptable for a human space flight. So we have to improve on that. So those packages we have identified and given an opportunity definitely ISRO will take up this challenge and complete it within the time frame.
Pallava Bagla: And they also have a plan of sending Indians to the moon?
G Madhavan Nair: At the moment we do not have any such plan but once we go to the low Earth orbit from there to travel to the moon and back it only depends on your propulsive power. We have new launch systems under development - semi-cryogenics and so on; with those propulsion modules we will be able to put together a system which can go to the moon and come back but perhaps it will take about 5 or 6 years beyond 2015 before we can attempt. But again it depends on the priorities on the national level and the type of world scenario. Already you know that USA and China - they have declared that by 2020 they would like to have their men on the lunar surface. I do not know whether India can afford to be lagging behind that.
Pallava Bagla: So we are looking at a 2020 scenario?
G Madhavan Nair: Well, we must work for it and definitely the nation has got capability and the strength to take on such a mission.
Pallava Bagla: So are you looking at it as some kind of a race you said if you can not be lagging behind?
G Madhavan Nair: No I did not say race. See, the superiority of any nation depends on the technical strength it has got, space in its own arena is where the highest level of technology is being demonstrated. Today I can say we are at par with the developed nations as far as technology is concerned. So if you want to be abreast in this field we have to invest in such areas like the human space flight.
Pallava Bagla: You have these, these are literally dreams, but you also had a failure not just in Chandrayaan - there was before that a hiccup on the telecom satellite which was prepared by ISRO for the European clients. What happened in that and has there been any progress on correcting that? Which is of course the W2M satellite?
G Madhavan Nair: Yes I think that satellite was launched. It was commissioned. It was in perfect shape when we handed it over to the customer but unfortunately maybe, quite possible due to some large electric discharge in the space, the power supply of it got affected. But we were a little bit worried you know the reaction time for such an event; normally in our spacecraft if any event occurs immediately we try to put in the safe mode until problem is resolved and so on. But this time lapse between the event and the reporting was more than 3 hours. By the time one part of the power supply was totally damaged. But I am happy to say that this spacecraft we took over from them [clients] and then afterwards we did certain correcting operations and at least half of the resources have been recovered and it has been given back to the customer. This I would say is the second innovative solution to fix problem.
Pallava Bagla: So should we call it a double failure or double success?
G Madhavan Nair: No, see space missions are always risky. Sixty per cent of the lunar missions were failures, but we made it [to the moon] in the first time. I would say it is our hard work plus an element of luck if you call. Again our own satellites if you look at it, we had an INSAT which is almost like a blind man. It does not have any sensor, it packed up in the first few months itself, but we tried to innovate on that. We tried to see how the earth reference could be obtained through some other means by the radio signals and so on and that spacecraft is almost going to complete 10 years now. So we because of our constraints in terms of the resources we cannot afford losses and also maybe [because we look at the spacecraft] as maybe our close associates, our teams work with that [idea] and make it happen.
Pallava Bagla: So you had a blind man working in space for you?
G Madhavan Nair: Yes I think it is a highly handicapped satellite [the INSAT] but it has served it's life.
Pallava Bagla: But what about Chandrayaan, is it also handicapped now?
G Madhavan Nair: No I will not say that. Yes we found glitches, but we were able to overcome by our redundancy plan.
Pallava Bagla: You would be able to complete its objectives?
G Madhavan Nair: It's almost completed its objectives. In the next season I can declare it to be 100 per cent over.
Pallava Bagla: And when do you expect for it to end its mission life?
G Madhavan Nair: I am planning to have a review by the scientific team maybe in a month's time or so. At the end of that we will take stock of the situation. If they want any additional data, that also we will service. After that we will say the mission is over.
Pallava Bagla: Will it affect our future missions with our Chandrayaan-2, you have a mission to Mars?
G Madhavan Nair: Not at all, you know. Even first time going to 100 kms distance to the moon it was a highly risky affair and we took the chance of going as close to as 100 kms. And we learnt quite a lot out of that. That learning meant that we have will help us in having more elaborate ways of managing the conditions for the future missions of Chandrayaan-2 and the Mars and so on.
Pallava Bagla: What a pleasure it was to speak to you Dr Nair and I wish you luck for many more missions.
G Madhavan Nair: It was nice interacting with you. Thank you.
Pallava Bagla: So that was Dr G Madhavan Nair, Chairman of ISRO, telling us that there are glitches in the Chandrayaan but they have been able to successfully fix and the satellite is able to give good data so that the scientific community is still very satisfied with the results.