During seven terrifying minutes next Monday Nasa scientists will watch, and wait, as £1.5bn of prime space technology hurtles through the wispy atmosphere of Mars at 13,200mph.
The scientists, who might be forgiven for forgetting to take a breath, will be watching as one of the most daring space missions ever attempted is played out.
It has taken eight long months for Nasa's 'Curiosity' rover to reach the red planet; and the one-ton vehicle the size of a Mini will be the most complicated piece of technology so far to visit Mars.
That is, of course, providing that the mission is successful.
The rover, which is designed to search for signs of life on the planet, must first safely land
Because the vehicle is so large and heavy getting it onto the planet in the first place presents a considerable challenge to scientists. The solution required, therefore, was always going to be bold. The option chosen is in fact so bold it has been described as 'crazy'.
After plunging into the Martian atmosphere at 13,200mph the capsule which holds 'Curiosity' will slow down due to friction, followed by the deploying of a supersonic parachute - nearly sixteen metres in diameter.
On its way to the surface of Mars the spacecraft will slow from 6 kilometers per second to a complete standstill.
It's the first time a guided-entry system has been used since the Apollo Moon programme of the 1960s and 1970s
During the descent an upper stage will be deployed, which resembles a flying bedstead - from this retro rockets will fire in order to slow the pace of the fall.
As it hovers over the landing site, the upper stage will transform itself into a "sky crane" and lower Curiosity to the surface on the end of a tether.
It will then break away, and deliberately crash.
Two British scientists, Dr John Bridges and Geologist Professor Sanjeev Gupta, are involved in the mission, and will help to direct the rover and analyse the data it will collect if the landing is successful.
Two-thirds of all missions to Mars have failed, including the ill-fated Beagle 2, which was lost on Christmas Day 2003.
Statistically the odds for a safe landing do not look good.
Dr John Bridges, from the University of Leicester Space Research Centre, one of the British scientists working on the Mars Science Laboratory mission, said: “I'm cautiously optimistic. Space exploration is not for the faint hearted.
“The previous rover landing used inflatable bouncing bags. Curiosity's just too heavy for that, so they developed the sky crane technique.”
The target for the rover is the Gale Crater, which is near to the Martian equator. There is particular interest in this area as there are geological signs of past water.
The aim of the mission is for 'Curiosity' to travel to a 5.5km tall peak, named Mount Sharp, in the centre of the crater.
There the six-wheeled moving laboratory will investigate its surroundings, analysing samples drilled from rocks or scooped from the ground.
The rover also carries a laser capable of vaporising rocks up to 30 feet away, producing a flash of light that can be used to collect chemical data.
Onboard the rover there is also a magnifying imager that is capable of revealing details smaller than a human hair. It also has a stereo camera to take panoramic shots of the planet.
Geologist Professor Sanjeev Gupta, from Imperial College London said: “Nasa chose Gale Crater as the landing site because it has a number of really exciting geological features that we are hoping to explore. These include a canyon and what appears to be a lake bed on the floor of the crater, as well as a channel and a delta, which we think may have been carved by water.
“We will use the rover's cameras, including one which is like a powerful magnifying glass, to study the geology up close.”
Dr Bridges also said that a key goal is to study sediments at the bottom of Mount Sharp.
Scientists think they are a reminder of a time, three to four billion years ago, when there was water on the surface of Mars.
“The clay layers may represent what we loosely call a warm and wet period in Martian history,” said Dr Bridges. “On the top of the mountain the rock was deposited under dry conditions, so there was a great environmental change.
“There's this idea that Mars was warm and wet long ago, but we don't know how long there were standing bodies of water on Mars, whether they were short lived or lasted hundreds of millions of years. That's important to the question of whether life ever existed there. Although we've made enormous strides in understanding Mars over the last 10 or 20 years, there's still a lot we don't know.”
An Atlas V rocket carrying Curiosity blasted off from Cape Canaveral, Florida, in November.
The journey to Mars involved crossing 352 million miles of space.