An artist's concept of NASA's Mars Science Laboratory spacecraft approaching Mars. The Curiosity rover is safely tucked inside the spacecraft's aeroshell. The mission's approach phase begins 45 minutes before the spacecraft enters the Martian atmosphere. It lasts until the spacecraft enters the atmosphere. For navigation purposes, the atmospheric entry point is 2,188 miles (3,522 kilometers) above the center of the planet. This illustration depicts a scene after the spacecraft's cruise stage has been jettisoned, which will occur 10 minutes before atmospheric entry.The landing is set for late evening August 5, 2012.
- Follow our live coverage of the daring Mars landing attempt, including a continuous NASA video livestream from 2pm today, with analysis by our expert studio panel.
- Preview: tense build-up to space-flight nailbiter
Later today three antennae at NASA's deep space tracking station near Canberra will tilt towards Mars and make contact with the planetary rover, Curiosity, as it prepares to descend onto the Martian surface.
This artist's concept shows the sky crane maneuver during the descent of NASA's Curiosity rover to the Martian surface. By the time the robotic Mars laboratory dubbed Curiosity streaks into the thin Martian atmosphere at hypersonic speed on Sunday night, the spacecraft will be in charge of its own seven-minute final approach to the surface of the Red Planet.
More than 40 years since Australia relayed man's first steps on the moon to the world, we will play a crucial role in NASA's latest space mission by communicating directly with the space probe as it makes its final approach. ''We're the only country in the globe that is going to be doing that,'' said the director of the Canberra Deep Space Communication Complex, Ed Kruzins.
The position of Earth to Mars puts Australia in a unique position to send and receive signals from the rover. The Parkes radio telescope in New South Wales and another antenna near Perth will provide back-up.
If all goes as planned, and that is far from guaranteed, the 900 kilogram rover, which has been cruising inside a spacecraft towards Mars since its launch in November, will touch down at 3.31pm AEST.
''I think the best way to describe the mission is audacious, but we're very confident of this working out,'' Dr Kruzins said. Fitted with the most advanced set of instruments ever sent to study the Red Planet, the rover's task during its two-year mission will be to determine whether Mars is, or ever was, habitable.
But before any Martian discoveries can be made, the rover must make its highly complex descent, which begins when the spacecraft enters the planet's atmosphere and requires a sequence of precise technical manoeuvres. The time delay between the two planets means the rover must land itself, an event NASA scientists call the ''seven minutes of terror''.
As the spacecraft slows from the friction of the planet's thin air, a 16-metre parachute will eject to further slow the ship before its heat shield separates and a sky crane device prepares to lower the rover into Gale Crater, a 150-metre wide depression named after the amateur Australian astronomer Walter Gale. During the final part of the descent the craft will lose contact with Earth and so send signals via the Mars Odyssey orbiter, which will hover above the landing site.
NASA's associate administrator in charge of the science mission directorate and the $US2.5 billion program, John Grunsfeld, said last month Curiosity's landing would be the ''hardest NASA mission ever attempted in the history of robotic planetary exploration''.
The spacecraft will communicate with the Canberra tracking station, which is managed by the CSIRO, through a series of tones, which signify various steps in the landing process have been activated. ''We'll be carrying the signals as it passes through the atmosphere, descends on its parachutes, fires its thrusters and lands on the surface,'' said Dr Kruzins.