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India on Sunday joined interplanetary travellers, after successfully conducting a critical manoeuvre to place the Mars orbiter spacecraft in the Mars transfer trajectory. The country's first mission to Mars left the Earth's orbit in the early hours of Sunday, clearing a critical hurdle in its journey to the red planet. The Indian Space Research Organisation (Isro) chairman, K Radhakrishnan, 64, spoke to T E Narasimhan about the preparation Isro underwent, the event's importance and the way forward for the mission. Edited excerpts:
India is the first Asian country and fourth nation in the world to leap into the interplanetary space, thanks to Sunday's development. How are you and your team feeling?
We feel that we have been able to do a good job and it is a satisfying experience. The entire team is happy. A lot of work has gone into it, including preparation for all possible contingencies. This being a very crucial operation, we have done a lot of analysis and simulation, considered possible contingencies and how to address them. Preparedness has been excellent.
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What contingencies were you expecting?
They could have been from any angle. Suppose the spacecraft was not ready for a trans-Mars injection since one of its subsystems had an anomaly. Then we would not have been able to do the trans-Mars insertion on Sunday and would have to wait for another four days.
An hour before the actual burn, the process starts with orienting the spacecraft properly for the firing. Suppose, during the process, we were not able to get the proper attitude stabilised. Or what if there was a problem with one of the specific components?
Then, as the burn starts, suppose in the propulsion system itself - where there are three major sections, the pressurisation system, the propulsion seed system & the engine itself - what if any component showed a problem in opening or closing properly or there was a leak?
We had to analyse all these things and be prepared for any possible failures. Thankfully, none of the contingencies occurred.
Was there any unexpected problem?
In the spacecraft movement, each station is going to have the visibility and just before the start of the burning, the South African station was receiving. There are two ground stations in South Africa. If one ground station has any problem, the other one can take it.
The sequence is that after the stations in South Africa get the visibility, it comes to the visibility of Mauritius and then to Bangalore.
Exactly one minute before the burn started, there was a thunderstorm and we did not have the data when the engine was fired. But within five minutes, we got it and started getting the data in real time. So there was this five-minute gap.
Did everything else go as planned? What is the status of the spacecraft now?
Everything is ok. We have got the performance of the liquid engine - around 1.75 per cent - more than what we assumed.
Before and after Sunday's operation, the spacecraft's health is normal. We had a review immediately after the operation and all the subsystems' chiefs had reported to us about the health and all are normal.
What are the next crucial dates?
The orbit that we got is as expected. At 4 am on December 2, the spacecraft would have crossed the lunar distance, that is, 384,490 km. At 0216 hours on December 4, it will get out of the sphere of influence of Earth. Then, we will observe for a few days. On December 11, we will have the first small mid-course correction manoeuvre. Subsequently, one will be in April and another one in August next year. These are all to ensure on September 24, 2014, we are 500 km, give or take 50 km, away from Mars. Two weeks before reaching Mars, there will be one more manoeuvre. So there will be four correction manoeuvres. The next crucial event is on September 24, which is the insertion of the spacecraft into Mars' orbit.
We will be observing and monitoring the spacecraft continuously. This is process is No 1 for all the systems' health. The second thing is the scientific systems that are on board. They need to be operated for the purpose of calibration. Four of them were put on during the Earth-bound phase itself.
During the coming days, we will also be switching on in a systematic way. The idea is to get the calibration and the background before we reach Mars, so we will know whatever is coming afterwards is attributed to Mars and whatever we are doing now in terms of calibration and the background has to be unequivocally understood and demonstrated. Only then will the reading we get through the instruments be accepted by the scientific community.
