IN the silence of space on the approach to Mars a US probe is warming up for an unprecedented act of theatre. Heaters aboard the spacecraft have begun to glow, thawing thrusters and components ahead of the most daring landing attempted on an alien world.

Bearing down on the red planet at more than 12,875kph, the Nasa craft is carrying the space agency’s Curiosity rover, a gangly off-road vehicle with robotic tools to scoop, drill and vaporise the soil and rocks strewn across the dusty landscape.

The rover’s job is to explore the geology of the enormous Gale crater basin, and uncover whether Mars was ever capable of harbouring life. But first it must touch down safely.

The $2.5bn mission blasted off in November on a journey of 482m kilometres. It is due to land the Curiosity rover on Aug 6.

The vehicle’s first port of call is what looks like an alluvial fan, a pattern of sediments thought to be created by flowing water billions of years ago.

Powered by a lump of radioactive plutonium and lithium-ion batteries, the rover is due to explore the Gale crater and its huge central mountain for one Martian year, or 687 Earth days.

Scientists are banking on the mountain being the key to the planet’s geological past. The rocks at the bottom may be more than 3.5bn years old.

Water is only part of the story. The roving laboratory will also look for molecular chains of carbon that are bound to hydrogen, another apparent prerequisite for life.

The rover is not designed to find direct evidence of alien life, for example in the form of fossilised micro-organisms. This is a prospecting mission, aimed at scouring the crater for sites where future rovers, or even human explorers, might find concrete evidence of past life on the planet.

But before the science can begin, the three-metre-long rover must touch down on Mars. The size of a family car, this is Nasa’s largest rover yet, and tried and tested means of landing on the planet are not sufficient to cushion the rover on impact.“She’s a beast,” said Ann Devereaux, an engineer who works on the crucial entry, descent and landing team. “The fact that we’re doing this crazy landing sequence allows us to pinpoint a target on the ground, but the previous ways we’ve landed on Mars simply wouldn’t work with this rover.”

Mission control will stop talking to the spacecraft two hours before it reaches Mars. There is nothing they can do to help it from that point.

Ten minutes before the spacecraft arrives it will jettison its cruise stage and swing the probe’s heat shield into a forward position. Small thrusters will line it up with its landing spot in the crater. The probe deploys a parachute and blasts the heat shield free, revealing a camera to record the descent — ‘the seven minutes of terror’. —The Guardian, London