India's Mars Mission Mangalayaan : What is in it for India?

Mayank Vahia

Dr.Mayank Vahia, from the Tata Institute of Fundamental Research, looks at the various facets of the Mars Mission – from the science of it, to its benefits and tells us why it is good for Science and for India

There is a pleasure in doing something difficult but the real challenge is doing the impossible.

Dr. K. Radhakrishnan, Chairman ISRO (Indian Science Research Organisation) has achieved this and more. He did not just one, but several impossible things in a stroke, at a time when his predecessor was extremely busy bad mouthing him. We all can only salute him and his team.

Why am I using so many superlatives and why have I singled out ISRO Chairman by name? Let me list out how many impossible things he achieved.

• Make a small, 1350 kg class satellite to go 25 crore kilometre and study another planet in the Solar System.
• Use one of the smallest commercial rockets in the world to launch it in such a way that the Earth is used as a slingshot to power the satellite on its way to Mars.
• Do this within a budget of 450 crore rupees.
• Design a mission with just 15 kg of scientific instruments, 470 kg of other instruments that can do good science.
• Achieve it in a span of 15 months.

Anyone who knows space engineering will tell you that to achieve each of these individually is next to impossible, let alone doing them together. For that alone he and his team deserve full credit.

So why did ISRO attempt this? Well, like people, countries do not live on bread and water alone. The worth of a nation is defined by the dreams it dares to dream. ISRO dreamt a dream and made it real.

Until a decade ago, ISRO was bogged down by routine engineering activities, in the area of remote sensing and communications. But a policy decision to outsource this work, to private sector Indian companies freed up scientists and engineers in ISRO to dream new dreams. Chandrayaan and now Mangalayan are the result of this far reaching policy change. You cannot get the best space engineers in the world to set up some of the finest facilities for space technology and then ask them to do mundane things like make remote sensing satellites all the time. Some half a dozen other countries can do that. May be the other 130+ countries can’t do it, but just doing that all the time is a waste of talent and boring for those involved. Radhakrishnan had to give them a challenge. It is a credit to his engineers that they rose to the challenge.

Designing a mission to Mars is no joke. Several missions to Mars have been lost to errors. Just working out its path and how to get there is Rocket Science! A small error in its velocity or its angle of release from earth can take the mission several thousands of kilometres from its trajectory by the time it covers the 25 crore kilometres to Mars over next 300 days (it took Chandrayan 4 days to reach Moon). And, because PSLV is a small rocket, they used the Earth’s gravity in a cunning manner as a slingshot to achieve this trajectory in most cost effective manner. It will take 25 days more (till the early hours of December 1) for this slingshot to pick up enough energy to send the spacecraft away from Earth and on its way to Mars. The spacecraft will then have to look after itself as it hurtles towards Mars. The interplanetary medium is harsh and the distance to Earth will be large. Signals from Chandrayan to Earth took about 1 second. From Mars they will take more than 350 seconds. So the spacecraft cannot wait for its parents at home to decide what it should do in case of an emergency.

Once it reaches Mars, it will have to do something meaningful. So what are ISRO’s strengths? First, designing complex trajectories that spacecrafts must follow. It has achieved this. Next, ISRO has unmatched capability of remote sensing and designing specialised instruments to look for specific features. So ISRO is using these capabilities to study Methane, Hydrogen, map Mars and get a mineralogical map of Mars. One more payload will look at the way the atmosphere of Mars reacts to Solar radiation.

So why these choices?

• First, the Methane sensor. Methane gas is highly reactive. So any methane in the atmosphere will react with other chemicals and will no longer remain methane. Yet, one can imagine life forms that can breathe methane. Some earlier spacecrafts had suggested that there is free methane in the atmosphere of Mars. This can only happen if there is at least some chemically (if not biologically or living) active region on Mars. Recent Mars rover did not find any Methane at the place where it landed but that does not mean it does not exist elsewhere. It is worth a shot.
• Hydrogen and deuterium or heavy hydrogen. Hydrogen forms water. But water that is made with heavy hydrogen is heavier and hence it evaporates differently compared to normal water and neither of these forms of hydrogen can exist in a free state on Mars. Hence knowing the deuterium to hydrogen ratio will give a good idea on how the water and other hydroxyl molecules behave in the Mars atmosphere and whether there is fractionation of hydrogen and deuterium on Mars compared to what it must have been when Mars was born.
• Next is the map of Mars. ISRO has built up admirable capability in making 2 and 3 dimensional maps of any remote object and they will now use it on Mars. Mineralogy map depends on the fact that different minerals shine differently and when gently heated by the Sun also shine in a signature way. ISRO will use these signatures to determine which mineral is located where on Mars.
• The last payload will look at neutral gases being ejected from Mars surface. Again this is an excellent study since we do not really understand how solar radiation interacts with atmosphere, especially since, unlike Earth, Mars has no protective magnetic field. This will be crucial to understanding Mars. So one Mangalyaan reaches Mars, there will be lots and lots of data about Mars.

Yet, there are critics. Some say we should focus on our hungry people, some say we should focus on Moon, some say we should focus on heavier rockets and should have sent a mission only when we had bigger rockets a few years from now and some even say that we should have spent money on competing with China in putting man in space. I think all these reasons are specious. Firstly, no country lives by food alone. It needs dreams and the worth of a nation is in its capacity to dream and fulfil these dreams. ISRO also did not stop everything else like developing bigger rockets for Mars mission – in fact ISRO has announced that they will test the bigger rocket as early as December this year. As regards feeding the poor with this money, remember that the money spent is miniscule and the problems with feeding the hungry has more to do with logistics and problems of delivery than on funding. Lastly, the idea that we should get into competition with China is just too silly to deserve a response. We live our dreams, let them live theirs. We build on our strengths. As for sending a bigger mission, it is a good idea that the first missions are modest. First learn to walk, then talk of running.

The last issue is, what is in it for common man? We all know that ISRO’s 20 years of labour in remote sensing and modelling the Earth saved thousands of lives in Odisha cyclone not even a couple of months ago. Technological developments may not put money directly into poor people’s pockets, but it certainly provides them with means of making money. It does not fish for the fishermen but tells them how and where to catch more fish safely. That is worth the trouble.

So as a scientist, I am excited about this new demonstration of technology by ISRO, as an Indian I am proud that on our behalf ISRO has dreamed an impossible dream and made it possible and as a tax payer I am happy that it has done so with so little money. Yes, I am a proud and happy man today.

Courtesy : DNA