Millions followed the voyage of NASA’s Mars Rover, Curiosity. The excitement hit fever pitch during the “seven minutes of terror” on August 6 as the 900-kg vehicle decelerated from 21,000 kmph to a touchdown at the Gale Crater on the surface of the red planet. The descent was flawless. The time taken varied less than a second from simulations. As the $2.5-billion (approximately Rs 13,900 crore) Curiosity entered the Martian atmosphere, it deployed heat shields, fired retro-rockets to slow, released a parachute to act as an airbrake, and shed ballast in the form of 75 kg tungsten weights. Curiosity’s onboard computers took all the decisions. Mars is about 14 light minutes (252 million km) distant at the moment, which meant there was no question of relaying instructions from Earth mission control. Software is being uploaded to what is now the Internet’s most distant node for a battery of experiments to be performed over the next two (Earth) years. Curiosity will investigate the planet’s mineral composition, search for water, amino acids and other bio-signatures indicating life, interpret geological processes from rock and soil structures, check atmospheric composition and planetary radiation signatures. All this is vital data for a planned manned Mars mission that is on NASA’s agenda. More than that, what is learnt will vastly aid the understanding of climatic and geological processes on Earth itself. If any signs of life are found, that will be a huge bonus.
Unmanned Mars missions present technical problems of a magnitude more complex than the Apollo moon landings that defined the 1960s. Out of 50 Mars missions undertaken so far by NASA, the European Space Agency, Russia, China and the former Soviet Union, the failure rate has been over 50 per cent. Out of ten lander and six rover missions, only three and four respectively have succeeded. The only mission designed to return with samples, Russia’s Phobos-Grunt, failed. Mars is just within the reach of, but not quite within the grasp of, technology. Curiosity took 253 Earth days to get there. The Mars-Earth distance varies from 55 million km to 400 million km. Missions must minimise energy usage and the ideal launch windows occur only every 26 months.
India’s Isro hopes to catch the next launch window in late November 2013, in a mission recently cleared by the Union Cabinet. If November 2013 is missed, the next window would arrive only in 2016, so there is need for haste. Isro’s Polar Satellite Launch Vehicle (PSLV-XL) will place an orbiter in an orbit of 500 x 80,000 km above the planet. The orbiter will carry 25 kg of scientific payloads to carry out experiments focussed on climate, geology, evolution and sustainability of life. The 2012-13 Budget allocated Rs 125 crore to the Mars mission, but it will cost around Rs 450 crore. Reportedly, Isro has already finalised the payloads.
Space exploration has always been a magnet for the imagination. Mars features in mythology and science fiction as a premier destination. The rocky red planet has significant atmosphere and a gravity of around 38 per cent of Earth. Its intriguing surface features, including cave and tunnel systems and polar ice-caps, imply distinct possibilities of sustaining life. The R&D involved in getting there, running experiments and analysing the data will push Isro’s capabilities up several notches. The competencies developed could translate into an enhanced understanding of India’s climate and of features such as glaciation, forest cover, water bodies, mineral deposits and so on. But going beyond the utilitarian, a Mars mission is worth doing because it’s there.