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
John Travolta is a qualified airline captain and employed the pilot with his company, Alto
people'That was the lowest I’d ever felt'
Life and Style
healthIt isn’t greasy. It doesn’t smell. And moreover, it costs nothing

Other places that have held independence referendums
Arts and Entertainment
Jack Huston is the new Ben-Hur

It scooped up an unprecedented 11 Academy Awards when it was first remade in 1959

Arts and Entertainment
Pharrell dismissed the controversy surrounding
musicThe singer said 'the last thing I want to do is degrade'

Arts and Entertainment
Blossoming love: Colin Firth as Stanley and Emma Stone as Sophie, in 'Magic in the Moonlight'

Actors star in Woody Allen's 'Magic in the Moonlight'

A male driver reverses his Vauxhall Astra from a tow truck
newsThe 'extremely dangerous' attempt to avoid being impounded has been heavily criticised
peopleThe Times of India said actress should treat it as a 'compliment'
Arts and Entertainment
Maxine Peake plays Hamlet at Manchester's Royal Exchange
theatreReview: Maxine Peake brings emotional ferocity to Shakespeare's starring part
ebooksAn unforgettable anthology of contemporary reportage

Watch this commuter wage a one-man war against the Circle Line
Home body: Badger stays safe indoors
lifeShould we feel guilty about keeping cats inside?
Life and Style

Olympic diver has made his modelling debut for Adidas


...and the perfect time to visit them

Jonas Gutierrez (r) competes with Yaya Toure (l)

Newcastle winger reveals he has testicular cancer - and is losing his trademark long hair as a result

Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

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

iJobs Job Widget
iJobs General

SEN Teaching Assistant Runcorn

£50 per day: Randstad Education Cheshire: SEN Teaching Assistant EBD , Septemb...

Head of Marketing - London

£60000 - £85000 per annum: Ashdown Group: Interim Head of Marketing / Marketin...

Primary supply teachers needed in Downham Market

£21000 - £35000 per annum: Randstad Education Cambridge: Primary teachers requ...

SEN Teacher

Negotiable: Randstad Education Birmingham: SEN Teacher required with immediate...

Day In a Page

Mystery of the Ground Zero wedding photo

A shot in the dark

Mystery of the wedding photo from Ground Zero
His life, the universe and everything

His life, the universe and everything

New biography sheds light on comic genius of Douglas Adams
Save us from small screen superheroes

Save us from small screen superheroes

Shows like Agents of S.H.I.E.L.D are little more than marketing tools
Reach for the skies

Reach for the skies

From pools to football pitches, rooftop living is looking up
These are the 12 best hotel spas in the UK

12 best hotel spas in the UK

Some hotels go all out on facilities; others stand out for the sheer quality of treatments
These Iranian-controlled Shia militias used to specialise in killing American soldiers. Now they are fighting Isis, backed up by US airstrikes

Widespread fear of Isis is producing strange bedfellows

Iranian-controlled Shia militias that used to kill American soldiers are now fighting Isis, helped by US airstrikes
Topshop goes part Athena poster, part last spring Prada

Topshop goes part Athena poster, part last spring Prada

Shoppers don't come to Topshop for the unique
How to make a Lego masterpiece

How to make a Lego masterpiece

Toy breaks out of the nursery and heads for the gallery
Meet the ‘Endies’ – city dwellers who are too poor to have fun

Meet the ‘Endies’ – city dwellers who are too poor to have fun

Urbanites are cursed with an acronym pointing to Employed but No Disposable Income or Savings
Paisley’s decision to make peace with IRA enemies might remind the Arabs of Sadat

Ian Paisley’s decision to make peace with his IRA enemies

His Save Ulster from Sodomy campaign would surely have been supported by many a Sunni imam
'She was a singer, a superstar, an addict, but to me, her mother, she is simply Amy'

'She was a singer, a superstar, an addict, but to me, her mother, she is simply Amy'

Exclusive extract from Janis Winehouse's poignant new memoir
Is this the role to win Cumberbatch an Oscar?

Is this the role to win Cumberbatch an Oscar?

The Imitation Game, film review
England and Roy Hodgson take a joint step towards redemption in Basel

England and Hodgson take a joint step towards redemption

Welbeck double puts England on the road to Euro 2016
Relatives fight over Vivian Maier’s rare photos

Relatives fight over Vivian Maier’s rare photos

Pictures removed from public view as courts decide ownership
‘Fashion has to be fun. It’s a big business, not a cure for cancer’

‘Fashion has to be fun. It’s a big business, not a cure for cancer’

Donatella Versace at New York Fashion Week