Nasa's seven minutes of terror to land Curiosity rover in mission to explore Mars

 

They call it the seven minutes of terror, and for good reason, as this is the perilously short length of time Nasa scientists have given themselves to land a space probe on Mars that will hit the Martian upper atmosphere at 13,200mph.

On Monday morning, a few seconds after 6.30am London time if all goes to plan, Nasa will know whether a $2.5bn (£1.67bn) gamble on a heat shield, a set of eight retrorockets and three nylon lines has paid off.

For the first time, a landing vehicle will be gently lowered to the surface of another planet using nylon tethers suspended from a mother spacecraft hovering precariously overhead.

A safe landing will be the culmination of a hair-raising journey through the thin Martian atmosphere which will have begun seven minutes earlier as Nasa's Mars Science Laboratory mission begins its entry and descent to the surface of the Red Planet.

During the "guided entry" phase small thrusters on the back of the spacecraft will adjust the angle and direction of movement, enabling the probe to make sweeping S-shaped turns that will help it to slow it down.

More than ninth-tenths of the deceleration will result from the intense friction generated between the spacecraft's heat shield and atmosphere, which will raise temperatures on the outside of the shield to 2,100C.

A 15.5m-wide parachute will be deployed about 254 seconds after entry, at an altitude of about seven miles and a velocity of some 900mph. This will slow the craft down to about 280mph, when the heat shield is jettisoned and video cameras and retrorockets begin to take control of the final few minutes of the descent.

The retro-engines are designed to slow the probe down to about 1.7mph when, just 20m above the surface of the planet, a "sky crane" will gently lower Curiosity, a six-wheeled rover vehicle the size of a Mini Cooper, on the three nylon tethers, a manoeuvre lasting about 12 seconds.

On touchdown, the mother craft above will cut the tethers and fly off to crash land well away from the landing site so as not to interfere with Curiosity's bank of scientific instruments designed to analyse Martian geology and search for fossilised signs of life.

Charles Elachi, director of Nasa's Jet Propulsion Laboratory, is under no allusion about the difficulty of the landing mission, which he said was equivalent to controlling the energy of 25 high-speed trains at full speed.

"That's the amount of energy we have to dissipate in six minutes so that we can land softly on the surface," Dr Elachi said on a recent visit to London.

"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 said.

Previous landings

Viking 1 and 2 (1975): successful orbiters and landers that took the first detailed images and soil samples.

Mars Global Surveyor (1997): provided high-res images from orbit and the surface.

Mars Pathfinder (1997): the first successful airbag landing of a six-wheeled rover.

Mars Climate Orbiter (1998): lost a year later due to a conversion error bringing it too close to the planet.

Mars Express and Beagle 2 (2003): successfully entered orbit but its lander disappeared.

Mars Exploration Rover Opportunity (2004): still roving.

Mars Reconnaissance Orbiter (2006): powerful camera and spectrometer looking for water.

Suggested Topics
Start your day with The Independent, sign up for daily news emails
  • Get to the point
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

Recruitment Genius: Senior Digital Marketing Consultant

£28000 - £45000 per annum: Recruitment Genius: A Senior Digital Marketing Cons...

Recruitment Genius: Assistant Stores Keeper

£16640 - £18500 per annum: Recruitment Genius: An Assistant Stores Keeper is r...

Recruitment Genius: Claims Administrator

£16000 - £18500 per annum: Recruitment Genius: This is an excellent opportunit...

Recruitment Genius: Software Developer - C# / ASP.NET / SQL

£17000 - £30000 per annum: Recruitment Genius: Developer required to join a bu...

Day In a Page

'It was first time I had ever tasted chocolate. I kept a piece, and when Amsterdam was liberated, I gave it to the first Allied soldier I saw'

Bread from heaven

Dutch survivors thank RAF for World War II drop that saved millions
Britain will be 'run for the wealthy and powerful' if Tories retain power - Labour

How 'the Axe' helped Labour

UK will be 'run for the wealthy and powerful' if Tories retain power
Rare and exclusive video shows the horrific price paid by activists for challenging the rule of jihadist extremists in Syria

The price to be paid for challenging the rule of extremists

A revolution now 'consuming its own children'
Welcome to the world of Megagames

Welcome to the world of Megagames

300 players take part in Watch the Skies! board game in London
'Nymphomaniac' actress reveals what it was really like to star in one of the most explicit films ever

Charlotte Gainsbourg on 'Nymphomaniac'

Starring in one of the most explicit films ever
Robert Fisk in Abu Dhabi: The Emirates' out-of-sight migrant workers helping to build the dream projects of its rulers

Robert Fisk in Abu Dhabi

The Emirates' out-of-sight migrant workers helping to build the dream projects of its rulers
Vince Cable interview: Charging fees for employment tribunals was 'a very bad move'

Vince Cable exclusive interview

Charging fees for employment tribunals was 'a very bad move'
Iwan Rheon interview: Game of Thrones star returns to his Welsh roots to record debut album

Iwan Rheon is returning to his Welsh roots

Rheon is best known for his role as the Bastard of Bolton. It's gruelling playing a sadistic torturer, he tells Craig McLean, but it hasn't stopped him recording an album of Welsh psychedelia
Russell Brand's interview with Ed Miliband has got everyone talking about The Trews

Everyone is talking about The Trews

Russell Brand's 'true news' videos attract millions of viewers. But today's 'Milibrand' interview introduced his resolutely amateurish style to a whole new crowd
Morne Hardenberg interview: Cameraman for BBC's upcoming show Shark on filming the ocean's most dangerous predator

It's time for my close-up

Meet the man who films great whites for a living
Increasing numbers of homeless people in America keep their mobile phones on the streets

Homeless people keep mobile phones

A homeless person with a smartphone is a common sight in the US. And that's creating a network where the 'hobo' community can share information - and fight stigma - like never before
'Queer saint' Peter Watson left his mark on British culture by bankrolling artworld giants

'Queer saint' who bankrolled artworld giants

British culture owes a huge debt to Peter Watson, says Michael Prodger
Pushkin Prizes: Unusual exchange programme aims to bring countries together through culture

Pushkin Prizes brings countries together

Ten Scottish schoolchildren and their Russian peers attended a creative writing workshop in the Highlands this week
14 best kids' hoodies

14 best kids' hoodies

Don't get caught out by that wind on the beach. Zip them up in a lightweight top to see them through summer to autumn
Robert Fisk in Abu Dhabi: The acceptable face of the Emirates

The acceptable face of the Emirates

Has Abu Dhabi found a way to blend petrodollars with principles, asks Robert Fisk