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
News
i100 In this video, the late actor Leonard Nimoy explains how he decided to use the gesture for his character
Arts and Entertainment
Secrets of JK Rowling's Harry Potter workings have been revealed in a new bibliography
arts + ents
News
Robert De Niro has walked off the set of Edge of Darkness
news The Godfather Part II actor has an estimated wealth of over $200m
Arts and Entertainment
Fearne Cotton is leaving Radio 1 after a decade
radio The popular DJ is leaving for 'family and new adventures'
ebooks
ebooksA special investigation by Andy McSmith
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

Sauce Recruitment: Retail Planning Manager - Home Entertainment UK

salary equal to £40K pro-rata: Sauce Recruitment: Are you available to start a...

Ashdown Group: Front-End Developer - London - up to £40,000

£35000 - £40000 per annum: Ashdown Group: Creative Front-End Developer - Claph...

Recruitment Genius: Product Quality Assurance Technologist - Hardline & Electric

£18000 - £24000 per annum: Recruitment Genius: The role in this successful eco...

Ashdown Group: QA Tester - London - £30,000

£28000 - £30000 per annum: Ashdown Group: QA Tester - London - £30,000 QA Tes...

Day In a Page

HIV pill: Scientists hail discovery of 'game-changer' that cuts the risk of infection among gay men by 86%

Scientists hail daily pill that protects against HIV infection

Breakthrough in battle against global scourge – but will the NHS pay for it?
How we must adjust our lifestyles to nature: Welcome to the 'Anthropocene', the human epoch

Time to play God

Welcome to the 'Anthropocene', the human epoch where we may need to redefine nature itself
MacGyver returns, but with a difference: Handyman hero of classic 1980s TV series to be recast as a woman

MacGyver returns, but with a difference

Handyman hero of classic 1980s TV series to be recast as a woman
Tunnel renaissance: Why cities are hiding roads down in the ground

Tunnel renaissance

Why cities are hiding roads underground
'Backstreet Boys - Show 'Em What You're Made Of': An affectionate look at five middle-aged men

Boys to men

The Backstreet Boys might be middle-aged, married and have dodgy knees, but a heartfelt documentary reveals they’re not going gently into pop’s good night
Crufts 2015: Should foreign dogs be allowed to compete?

Crufts 2015

Should foreign dogs be allowed to compete?
10 best projectors

How to make your home cinema more cinematic: 10 best projectors

Want to recreate the big-screen experience in your sitting room? IndyBest sizes up gadgets to form your film-watching
Manchester City 1 Barcelona 2 player ratings: Luis Suarez? Lionel Messi? Joe Hart? Who was the star man?

Manchester City vs Barcelona player ratings

Luis Suarez? Lionel Messi? Joe Hart? Who was the star man at the Etihad?
Arsenal vs Monaco: Monaco - the making of Gunners' manager Arsene Wenger

Monaco: the making of Wenger

Jack Pitt-Brooke speaks to former players and learns the Frenchman’s man-management has always been one of his best skills
Cricket World Cup 2015: Chris Gayle - the West Indies' enigma lives up to his reputation

Chris Gayle: The West Indies' enigma

Some said the game's eternal rebel was washed up. As ever, he proved he writes the scripts by producing a blistering World Cup innings
In Ukraine a dark world of hybrid warfare and murky loyalties prevails

In Ukraine a dark world of hybrid warfare

This war in the shadows has been going on since the fall of Mr Yanukovych
'Birdman' and 'Bullets Over Broadway': Homage or plagiarism?

Homage or plagiarism?

'Birdman' shares much DNA with Woody Allen's 'Bullets Over Broadway'
Broadchurch ends as damp squib not even David Tennant can revive

A damp squib not even David Tennant can revive

Broadchurch, Series 2 finale, review
A Koi carp breeding pond, wall-mounted iPads and a bathroom with a 'wellness' shower: inside the mansion of Germany's 'Bishop of Bling'

Inside the mansion of Germany's 'Bishop of Bling'

A Koi carp breeding pond, wall-mounted iPads and a bathroom with a 'wellness' shower