Nasa prepares for $2.5bn gamble on Mars landing

'Sky crane' will lower robotic probe on to Red Planet in latest attempt to uncover signs of life

On 6 August at precisely 13 seconds after 6.30 in the morning London time, Nasa scientists should receive a message from Mars telling them whether their $2.5 billion (£1.67bn) gamble on three nylon lines has paid off.

Click here to see the 'Mission to Mars: six minutes to land on the red planet' graphic

This will be the moment when, for the first time, tethers will be used to gently lower a six-wheeled robotic rover the size of a Mini Cooper down to the surface of another planet from a spacecraft hovering precariously overhead.

Once Nasa's Curiosity rover touches the surface of the Red Planet six months from today, its 25 foot-long umbilical cord will be cut from its carrier ship, which will then use its bank of retro-rockets to crash-land well away from the site where the rover will begin its mission to search for the chemical signatures of Martian life.

"We will be very nervous. Landing on another planet is not a walk in the park. It's very challenging and there have been mixed successes and failures in the past," said Charles Elachi, director of Nasa's Jet Propulsion Laboratory in Pasadena, California, where the probe was designed and built.

Several previous space missions to Mars have ended in failure during the approach and landing phase. Britain's Beagle 2 probe disappeared during its airbag-cushioned landing in 2003.

"The reason we are nervous is that it's about 3 tonnes of mass coming in at a speed of almost 12,000mph and we have to land softly in less than six minutes," Dr Elachi said yesterday in London.

"We usually call it the six minutes of terror. When you are coming in at 12,000mph with that kind of mass it's equivalent in terms of energy to 25 high-speed trains going at full speed," he said.

"That's the amount of energy we have to dissipate in those six minutes so that we can land softly on the surface. In addition, the accuracy we have to point to be at the right angle is equivalent to me being in Los Angeles and hitting a golf ball to land in a hole on St Andrew's golf course in Scotland," he added.

Much of the immense kinetic energy of the spacecraft will be soaked up by the probe's heat shield as it enters the Martian atmosphere. This will reduce its speed tenfold to allow parachutes to slow it down still further, Dr Elachi said.

But the critical moments will come towards the end of the six minutes when the carrier craft nears its final approach to the Martian surface. It is then that the retro-rockets must fire precisely to allow the tethers to be released from the carrier's "sky crane".

"Retro rockets will slow us down further and when we are hovering about 30 feet above the surface, the sky-crane will lower the rover down. It's a little bit different from before when we used airbags, because this rover is so much bigger that airbags will not be practicable," Dr Elachi said.

The Curiosity probe will land at the foot of a geologically layered mountain inside a crater called Gale. The site was picked for its accessibility and for the fact that it is near an "alluvial fan" of sediments that could have been formed by running water at a time when life on Mars may have existed.

Asked whether Curiosity could finally answer the question about whether there was life on Mars, Dr Elachi replied: "Yeah, it could happen, if it's there."

Suggested Topics
Start your day with The Independent, sign up for daily news emails
Voices
There will be a chance to bid for a rare example of the SAS Diary, collated by a former member of the regiment in the aftermath of World War II but only published – in a limited run of just 5,000 – in 2011
charity appealTime is running out to secure your favourite lot as our auction closes at 2pm tomorrow
News
Elton John and David Furnish will marry on 21 December 2014
people
News
people
Arts and Entertainment
Caroline Flack became the tenth winner of Strictly Come Dancing
tvReview: 'Absolutely phenomenal' Xtra Factor presenter wins Strictly Come Dancing final
PROMOTED VIDEO
Life and Style
A still from the 1939 film version of Margaret Mitchell's 'Gone with the Wind'
life
Arts and Entertainment
J Jefferson Farjeon at home in 1953
booksBooksellers say readers are turning away from modern thrillers and back to golden age of crime writing
Sport
Amir Khan is engaged in a broader battle than attempting to win a fight with Floyd Mayweather
boxing Exclusive: Amir Khan reveals plans to travel to Pakistan
News
Stacey Dooley was the only woman to be nominated in last month’s Grierson awards
mediaClare Balding and Davina McCall among those overlooked for Grierson awards
Voices
Joseph Kynaston Reeves arguing with Russell Brand outside the RBS’s London offices on Friday
voicesDJ Taylor: The great tradition of St Paul and Zola reached its nadir with a worker's rant to Russell Brand
News
Twitchers see things differently, depending on their gender
scienceNew study shows that birdwatching men have a lot in common with their feathered friends...
News
i100
News
Xander van der Burgt, at the Royal Botanic Gardens, Kew
scienceA Kew Gardens botanist has found 25 new large tree species - and he's sure there are more out there
ebooks
ebooksA year of political gossip, levity and intrigue from the sharpest pen in Westminster
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs General

Austen Lloyd: Senior Private Client Solicitor

Excellent Salary: Austen Lloyd: SURREY - An outstanding high level opportunity...

Austen Lloyd: Construction Solicitor - London

Very Competitive Salary : Austen Lloyd: NICHE CITY FIRM - We are making a disc...

Austen Lloyd: Construction Solicitor - London

Very Competitive Salary : Austen Lloyd: NICHE CITY FIRM - We are making a disc...

Recruitment Genius: Finance Director

£65000 - £80000 per annum: Recruitment Genius: Finance Director required to jo...

Day In a Page

The week Hollywood got scared and had to grow up a bit

The week Hollywood got scared and had to grow up a bit

Sony suffered a chorus of disapproval after it withdrew 'The Interview', but it's not too late for it to take a stand, says Joan Smith
From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?

Panto dames: before and after

From Widow Twankey to Mother Goose, how do the men who play panto dames get themselves ready for the performance of a lifetime?
Thirties murder mystery novel is surprise runaway Christmas hit

Thirties murder mystery novel is surprise runaway Christmas hit

Booksellers say readers are turning away from dark modern thrillers and back to the golden age of crime writing
Anne-Marie Huby: 'Charities deserve the best,' says founder of JustGiving

Anne-Marie Huby: 'Charities deserve the best'

Ten million of us have used the JustGiving website to donate to good causes. Its co-founder says that being dynamic is as important as being kind
The botanist who hunts for giant trees at Kew Gardens

The man who hunts giants

A Kew Gardens botanist has found 25 new large tree species - and he's sure there are more out there
The 12 ways of Christmas: Spare a thought for those who will be working to keep others safe during the festive season

The 12 ways of Christmas

We speak to a dozen people who will be working to keep others safe, happy and healthy over the holidays
Birdwatching men have a lot in common with their feathered friends, new study shows

The male exhibits strange behaviour

A new study shows that birdwatching men have a lot in common with their feathered friends...
Diaries of Evelyn Waugh, Virginia Woolf and Noël Coward reveal how they coped with the December blues

Famous diaries: Christmas week in history

Noël Coward parties into the night, Alan Clark bemoans the cost of servants, Evelyn Waugh ponders his drinking…
From noble to narky, the fall of the open letter

From noble to narky, the fall of the open letter

The great tradition of St Paul and Zola reached its nadir with a hungry worker's rant to Russell Brand, says DJ Taylor
A Christmas ghost story by Alison Moore: A prodigal daughter has a breakthrough

A Christmas ghost story by Alison Moore

The story was published earlier this month in 'Poor Souls' Light: Seven Curious Tales'
Marian Keyes: The author on her pre-approved Christmas, true love's parking implications and living in the moment

Marian Keyes

The author on her pre-approved Christmas, true love's parking implications and living in the moment
Bill Granger recipes: Our chef creates an Italian-inspired fish feast for Christmas Eve

Bill Granger's Christmas Eve fish feast

Bill's Italian friends introduced him to the Roman Catholic custom of a lavish fish supper on Christmas Eve. Here, he gives the tradition his own spin…
Liverpool vs Arsenal: Brendan Rodgers is fighting for his reputation

Rodgers fights for his reputation

Liverpool manager tries to stay on his feet despite waves of criticism
Amir Khan: 'The Taliban can threaten me but I must speak out... innocent kids, killed over nothing. It’s sick in the mind'

Amir Khan attacks the Taliban

'They can threaten me but I must speak out... innocent kids, killed over nothing. It’s sick in the mind'
Michael Calvin: Sepp Blatter is my man of the year in sport. Bring on 2015, quick

Michael Calvin's Last Word

Sepp Blatter is my man of the year in sport. Bring on 2015, quick