Soft land on Moon - Done. Mission to Sun - Done. Test flight for Gaganyaan (India's first manned spaceflight) - Done. Next up - Venus and Mars. India's space research agency - ISRO - has set its sights on Earth's planetary neighbours and expects to mark the country's presence on Mars and Venus within five years, Dr M Sankaran, Director of the UR Rao Satellite Center in Bengaluru told NDTV.
Dr Sankaran - who heads the "powerhouse" unit behind the dozens of Indian satellites in orbit - identified some challenges, but revealed that internal talks on mission concepts are already underway.
Each comes with its own challenges, such as the spacecraft overheating on entry into Mars' atmosphere and finding an optimum launch window for each mission. Then there are common logistical challenges, like developing launch vehicles capable of carrying heavier payloads - more fuel, more equipment, etc. - needed for missions to Mars, Venus or beyond.
"The past couple of years... we have been studying mission configurations for landing on Mars. There are two things that were holding us back. One was Chandrayaan-2's unsuccessful landing, which slowed our confidence in sensors required for landing... it wasn't that the sensors did not perform well, but since we could not achieve our final goal we were not sure if these were adequate. Now we know what can be done, we can move forward," Dr Sankaran explained.
"The second is about our ability to put higher mass into orbit. Now, with present LVM3 (Launch Vehicle Mark-3, or what was earlier called Geosynchronous Satellite Launch Vehicle Mark III - the three-stage medium-lift launch vehicle developed by ISRO) capacity, still we have gap to meeting landing requirements because this is quite high. It has some challenges - in addition to a gravity field, like on the Moon, the atmosphere also poses a challenge. Heating (of the spacecraft) that occurs during entry into Mars' atmosphere calls for additional thermal protection, which is again mass. (But) we are studying this..." he told NDTV.
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It isn't all doom and gloom though. Dr Sankaran said enhancements to the LVM3 are ongoing and that ISRO expects 20-30 per cent greater payload capacity within the next two years. This is crucial not only for India's future space missions but also to allow the agency to carry more satellites for paid launches by other countries, which is a key revenue driver.
"I think we have now a possibility... with that as a target (about 20-30 per cent capacity increase in two-three years), we should be able to come up with a plan for a Mars lander mission. We have the outline.. now we need to move forward."
The proposed Mars mission will be India's second, after the success of Mangalyaan that was launched in November 2013; the country's first Mars mission began orbiting the planet in September 2014 and send volumes of priceless data before ISRO lost contact with the module in October last year. The mission to Venus will be India's first.
On the mission to Venus - dubbed Shukrayaan - Dr Sankaran had more good news to offer.
"We have actually gone up to preesenting internal reviews for concepts... this is going to be orbiter. Chandrayaan-3 success has given us confidence and the establishment also... so I think it should be possible, yes, to carry it forward," he said.
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"Mars and Venus missions have cyclical opportunities in terms of energy (use). We can launch any day... but depending on relative position of Earth and Sun, some year we get chance with minimum energy requirement. For Venus the next is in two years but that is too short, so may be in four to five years..."
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In September ISRO chief S Somanath had confirmed the Venus mission had been configured and some payloads were under development. Speaking at an event, he also said ISRO is planning studies to analyse the climate of space.
Meanwhile, last week ISRO shared a remarkable update from the Aditya-L1 mission, which is India's first attempt to study the Sun. The Hel1OS spectrometer - which was designed and built by Dr Sankaran's UR Rao Satellite Center - captured the first high-energy X-ray glimpse of solar flares.
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