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Tuesday, March 31, 2020

An expert explains: 10, 9, 8… in the end, it was the 7 terrifying minutes

A celebrated NASA scientist explains the significance of the Chandrayaan-2 mission – for ISRO, India, the world, and humankind as a whole.

Written by Amitabha Ghosh , Edited by Explained Desk | Updated: September 7, 2019 7:24:27 am
expert explains: chandrayaan 2 moon landing tonight Chandrayaan-2 might provide information related to the location of water ice deposits in permanently shadowed craters on the Moon.

Imagine a spacecraft hurtling through space, at 10 times the speed of an airplane, having to nearly come to a standstill in order to land gently on the Earth — all in a matter of a few minutes and, more importantly, without any human intervention. This, in a nutshell, is a soft landing.

The thought of a soft landing on another planet or the Moon drives chills down my spine: despite the fact that I have done this quite a few times through my career. The first time was way back in 1997, when NASA’s Mars Pathfinder, landed on Mars. I still remember the raw happiness when we received the first signal of the spacecraft from the surface of Mars! After that, there was the successful landing of NASA’s twin Mars rovers, Spirit and Opportunity, in 2004, followed by the lander, Mars Phoenix, in 2008 and the Mars rover, Curiosity, in 2012. Follow Chandrayaan-2 LIVE updates

VIDEO | Chandrayaan 2: Everything about moon landing

And, there was the dejection of a few failures, like NASA’s Mars Polar Lander in 1999 and ESA’s Beagle rover that crashed while trying to land on Mars in 2003. More recently, I watched the first private mission to the Moon, Beresheet, end tragically.

And, in the end, it was these terrifying minutes that ended in the loss of communication from the lander to the ground station.

READ | Chandrayaan-2 landing: 15 ‘terrifying’ minutes to history tonight

Five hundred years back, it took sheer courage to try explore lands separated by oceans: the distance at the time was of the order of 10,000 miles. Similarly, today, Space Exploration is not for the faint of heart: the distances that a spacecraft travels to different destinations is of the order of 100,000 miles for the Moon, 100 million miles for Mars and billion miles for a mission to Pluto. TV animation has made space exploration look deceptively simple: there is an animation that plays of the landing, there are shots of the mission control room that erupts in cheers; but the technology, the human effort and the nerves to undertake such a journey is just as harrowing and nerve-wracking.

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No signal from the lander means that there are a few possibilities — like a communication glitch, a possible power issue with the rover, but can also carry the dire prognosis that the rover did not survive the landing. That the rover hit the ground at an unacceptably high speed and was destroyed. The huge work done by a few thousand scientists and engineers, over half a decade or more, hinged on this critical signal post landing.
For, what made ISRO’s journey so topical and relevant was its landing site.

Though not exactly at the South Pole, the landing site was as far as any spacecraft has gone in the Southern Hemisphere. NASA’s human landings about 50 years back, have been mostly near the Lunar Equator. In contrast, Chandrayaan-2’s landing site is close to permanently shadowed craters near the South Pole that might store water ice.

Human aspiration for lunar colonization is no longer science fiction. A mixture of billionaires and governments have made the Moon the most desirable destination in the Solar System. Amazon’s Jeff Bezos, with a reputation of delivering on his ideas, has put his passion and his billions behind his lunar dreams: that include plans to build a large lander that can start transporting tons of material to the Moon to start work on a Lunar base. The target timeline is in the coming decade. NASA, in parallel, is planning to return American astronauts to the Moon with the Artemis project by 2024. The moon is of great scientific interest to the Chinese as well.

The rationale of a lunar base is as follows.

The thinking is that humans really live in narrow ranges of temperature, pressure, humidity, radiation levels and other attributes. Such an environment can be replicated in a habitation module. Such a habitation module should be possible on the Moon and Mars. The thought is to build a mini-city on the Moon or a Lunar base with houses (or habitation modules) where humans live, together with support infrastructure like a power generation grid, communication network and vehicles for surface mobility. Between Moon and Mars, the Moon seems to be a preferred destination for a permanent base. This is because Mars is too far away – about 1000 times compared to the Moon – and has a long round trip travel time (of at least 1 year) from Earth. The journey to the Moon, in contrast, can be traversed in 3 days, provided a powerful launch vehicle is available.

Read | Chandrayaan-2 timeline: From launch to loss of contact with Vikram lander

But, there is one glitch. In order to rationalize costs, two fundamental human needs, water and oxygen, need to be available from lunar materials and a fundamental logistics requirement, rocket fuel, needs to be extracted and produced on the Moon. Transporting water, oxygen or rocket fuel from Earth would exponentially increase costs to untenable levels. Thus, for the lunar base to be cost effective, the availability of water on the moon is critical. A deposit of lunar water can provide for all three needs.

This is why Chandrayaan-2 was so important.

Chandrayaan-2 would have provided information related to location of water ice deposits in permanently shadowed craters on the Moon. This will have a bearing on plans by NASA and Jeff Bezos’s company, Blue Origins, to explore the Moon. Specifically, the location and extent of water ice deposits, might prompt further robotics missions and technology development efforts to effectively extract, transport and store the water.

It has been a huge journey for ISRO and for India. From not having a Planetary Exploration Program in 2000, ISRO was all set to soft land on another heavenly body. India’s hope and aspirations seem to be now tied, at least in part, to its Space Exploration Programme. Going by how well received all of ISRO’s missions to the Moon and Mars have been so far, it seems Space Exploration might perhaps become an Indian passion, something all Indians can agree with and are proud of. Failure of one mission, on this journey, could also be one giant learning step.
Amitabha Ghosh is Chair of the Science Operations Working Group of the NASA Mars Exploration Rover Mission.

(Dr Amitabha Ghosh is Chair of the Science Operations Working Group of the NASA Mars Exploration Rover Mission.)


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