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Monday 7 September 2009

India's inaugural Chandrayaan-1 Moon mission a success or a failure?


India has abandoned its inaugural Moon mission, 10 months after it was launched. Science writer Pallava Bagla examines the mission's performance.

So was India's inaugural Chandrayaan-1 Moon mission a success or a failure?

Neither. By all accounts, it has been a mixed performance. Also, a definitive answer is not easy to give - it is possibly as grey as the surface of the Moon.

This was an expensive scientific experiment with many objectives and conducted in full public glare.

Most engineering goals have been fulfilled, but pious promises to deliver "good science" from the mission are still to be met.

Big achievement

India launched its $100m unmanned spacecraft on 22 October 2008 from Sriharikota on the coast of the Bay of Bengal.

First, the spacecraft designed and built by the Indian Space Research Organisation (Isro) survived huge odds and successfully reached the Moon's orbit.

This in itself was a big achievement since neither Russia nor America succeeded in their maiden attempts; and there were several failures even before they got anywhere near the Moon.

So did India ride on the shoulders of earlier successes?

Certainly not, since the know-how and technologies to go to the Moon are just not available for the asking. Each nation has to learn on its own. India experimented and did that with complete success.

The only other country to have managed a similar maiden feat was China - its mission Chang'e-1 in 2007 lasted 16 months in space, according to the Chinese National Space Administration.

The Indian mission survived for about 10 months in space; most other missions to the Moon have been much more short-lived.

So did the Indian space agency, in its naivety, over-stretch and over-estimate the craft's life when it planned for a 24-month mission?

Rocket carrying 10 satellites is launched from Sriharikota
The mission lasted 10 months in space

Possibly. The answer may emerge in the findings of the "failure analysis committee" that Isro has put in place after this debacle.

Despite being dubbed by Isro as an "engineering success", the mission had a rough ride around the Moon.

A fuel leak from the rocket almost aborted its lift-off. Within days of reaching the Moon, a power system failed, and a back-up system had to be activated.

Soon, the spacecraft started overheating due to the intense heat on the Moon. Isro scientists say it was deft mission management that saved it from a total burnout.

A few months into the mission the spacecraft lost its fine guidance system when the onboard "star sensor" packed up in the intense radiation around the Moon.

But, every time an instrument on this 1,380kg robot gave way, mission controllers at Isro found an innovative solution to keep the mission alive.

Finally on 29 August 2009, the space agency lost all contact with Chandrayaan after a catastrophic failure - possibly in its power supply system. A day later, the mission was "terminated", although Isro chief G Madhavan Nair declared it had been a "complete success".

'Two-in-one mission'

The Indian mission was in certain respects much more challenging than the Chinese maiden lunar mission which was a simple national orbiter.

Chandrayaan-1 was literally a two-in-one mission, since the main satellite was to orbit at 100km above the Moon and then a tiny gadget the size of a computer monitor was to attempt a "landing" on the Moon's surface.

The mission did this on 14 November 2008. No nation to date had succeeded in both a lunar orbiter and an impactor at the first attempt.

Madhavan Nair
Mr Nair says the mission is a 'complete success' (Photo: Pallava Bagla)

This was more than an experiment. It was also a brave global geo-political statement since the probe that crash-landed on the Moon also permanently placed India's flag on the lunar surface.

India became the fourth space bloc to have done this after Russia, America and the European Space Agency.

This is hugely significant because, if ever the Moon's resources are to be divided, India's rightful share can be claimed having achieved what others have not been able to do.

There are many other firsts to this mission.

In a highly un-Indian trait, the Indian space agency delivered the Moon mission with no cost or time overrun at $100m and within eight years of it first being suggested.

The spacecraft carried 11 different sophisticated instruments, one of the largest suites of experiments ever carried to the Moon.

The objective was to remotely map the resources of the Moon, prepare a three-dimensional atlas of it and look for water.

All instruments worked for about 10 months in the hostile lunar environment. Dr Nair calls it a "more than 100% success of Indian technology".

India also created a new model of international partnership.

Moon surface picture by Chandrayaan-1
Chandrayaan peered into the deepest craters searching for water

On its own initiative, India announced that it would be happy to piggyback instruments from global partners.

After a huge competition, six instruments sourced from the European Space Agency (Esa), the National Aeronautics and Space Administration (Nasa) and Bulgaria were chosen.

Bernard Foing, the chief scientist for Space Sciences at Esa, calls the Indian mission "the first multi-continent, multi-country lunar mission ever to be undertaken".

A little known fact is that India did not charge any money to fly these instruments 400,000km away: all got a free ride to the Moon, merely in exchange for sharing the scientific data.

Search for water

Chandrayaan-1 was also the first and the most detailed search for water on the Moon using radars - to date, water has never been found.

A miniature American radar onboard the Chandrayaan peered into the Moon's deepest craters searching for "water ice".

The Moon's surface is so parched that scientists feel the only location where water could exist would be in the permanently shadowed craters on the lunar poles.

But these are so deep and dark that sunlight never reaches them - hence the only way to peep inside is to send a radar signal down into them.

The global collaborative team of the mission is very excited about the findings.

"Never seen before images of the permanently shadowed craters of the Moon have been captured," says Paul D Spudis, of the Lunar and Planetary Institute, Houston, US, and principal investigator of the payload sent to search for water.

"The new radar images are not only visually arresting, but they will be extremely useful in unravelling the complex geological history of the Moon as a whole," he says.

Other scientific reports on findings are in the offing. But unless the results are published, questions will continue to be asked about whether the mission fulfilled its exalted scientific objectives.

The termination of the Moon mission will, however, not affect India's plans in space.

The country is already planning a second mission to the Moon, Chandrayaan-2, with Russian collaboration in 2011-12; a mission to an asteroid; an unmanned mission to Mars in 2013 and a human spaceflight in 2015.

Upbeat Isro scientists are saying "Chandrayaan-1 is dead, long live Chandrayaan". The jury will be out - until the scientific papers come in.

Pallava Bagla is the Science editor for New Delhi Television (NDTV) and author of Destination Moon - India's quest for Moon, Mars and Beyond.

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