On August 6 Nasa’s Curiosity rover, packed inside the Mars Science Laboratory spacecraft, will hurtle towards the Martian surface at around 13,200mph – and has just over six minutes to slow down and make a soft landing.
What’s more, the craft has to be at just the right angle for the descent to be a success – likened by one Nasa scientist to firing a golf ball from Los Angeles to land in a hole at St Andrew’s in Scotland.
The mission's entry, descent, and landing (EDL) phase begins when the spacecraft reaches the top of Martian atmosphere, about 81 miles (131 kilometres) above the surface of the Gale crater landing area, and ends with the rover safe and sound on the surface of Mars.
Scroll down for video
Gently does it: Curiosity will be lowered down by a Sky Crane craft fitted with retro boosters
Speedy: The Mars Science Laboratory spacecraft, with Curiosity inside, will hit the Martian atmosphere at 13,200mph
Red alert: Curiosity will probe the Martian environment using highly advanced instruments
During the EDL, the three-ton spacecraft decelerates from a velocity of about 13,200 miles per hour (5,900 metres per second) at the top of the atmosphere, to stationary on the surface.
Most of the enormous deceleration needed will be achieved by friction with the atmosphere. In the final stages a parachute will be deployed and the Curiosity rover will pop out of the main craft attached by nylon tethers to a Sky Crane fitted with retro rockets.
This craft will hover above the surface and gently lower Curiosity down.
How Curiosity will make its nervy landing on the Martian surface
Size matters: The Mars Science Laboratory is the biggest and most sophisticated planet-roaming machine ever to be deployed
It’s a set of manoeuvres that’ll leave staff at mission control with sweaty palms.
Dr Charles Elachi, director of Nasa's Jet Propulsion Laboratory in Pasadena, California, where the probe was built, told The Independent: ‘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.’
In 2003, for instance, Britain’s Beagle 2 probe lost contact with Earth as it came into land and was never heard from again.
Elachi added: ‘The reason we are nervous is that it's about 3 tonnes of mass… equivalent in terms of energy to 25 high-speed trains going at full speed. 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.’
About to have a blast: The Mars Science Laboratory, with Curiosity inside, being transported to the launch pad
Up, up and away: The rocket carrying curiosity took off successfully on November 26 last year
- On average it lies 141.6 million miles from the Sun.
- With a diameter of 4,222 miles, it’s around half the size of the Earth.
- It’s absolutely freezing there, with an average temperature of -85F (-65C).
- Gravity is much less powerful - slightly less than 40 per cent of ours.
- The atmosphere is desperately thin – one per cent of Earth’s pressure – and not very nice for us humans because 95 per cent of it is carbon dioxide.
- It boasts the solar system’s biggest mountain – Olympus Mons, a dead volcano with staggering proportions. It measures 335 miles across and rises to a height of 88,000ft, which is almost three times higher than Everest.
- Mars has two cosmic sidekicks – the moons Deimos and Phobos.
- Mars’s red colouring comes from the iron oxide that coats its surface.
- Mars has huge amounts of ice at its polar caps. If they melted, it would cover the whole planet in water 11-metres deep, according to Nasa.
Nasa’s most advanced mobile robotic laboratory will examine one of the most intriguing areas on Mars.
Curiosity is a rover with more scientific capability than any ever sent to another planet.
It will set down inside a huge crater and use its highly advanced instruments, including cameras and lasers, to find out more about the planet’s environment, which will help pave the way for human missions.
Doug McCuistion, director of the Mars Exploration Program at Nasa Headquarters in Washington, said: ‘Mars Science Laboratory builds upon the improved understanding about Mars gained from current and recent missions.
‘This mission advances technologies and science that will move us toward missions to return samples from, and eventually send humans to, Mars.’
The one-ton rover will examine Gale Crater during a mission that will last nearly two years.
Curiosity will land near the base of a layered mountain three miles (five kilometres) high inside the crater.
The rover will investigate whether environmental conditions have ever been favourable for development of microbial life and preserved evidence of those conditions.
John Grotzinger, project scientist for the Mars Science Laboratory at the California Institute of Technology in Pasadena, said: ‘Gale gives us a superb opportunity to test multiple potentially habitable environments and the context to understand a very long record of early environmental evolution of the planet.
‘The portion of the crater where Curiosity will land has an alluvial fan likely formed by water-carried sediments. Layers at the base of the mountain contain clays and sulphates, both known to form in water.’
Curiosity is twice as long and five times as heavy as earlier Mars rovers Spirit and Opportunity.
The rover will carry a set of 10 science instruments weighing 15 times as much as its predecessors' science payloads.
A mast extending to seven feet (2.1 metres) above ground provides height for cameras and a laser-firing instrument to study targets from a distance.
Instruments on a seven-foot-long (2.1-metre-long) arm will study targets up close.
Analytical instruments inside the rover will determine the composition of rock and soil samples acquired with the arm's powdering drill and scoop.
Other instruments will characterise the environment, including the weather and natural radiation that will affect future human missions.