"We have worked for four years to get to this point, so we are all very excited," Barry Goldstein, the Phoenix project manager, said at NASA's Jet Propulsion Laboratory in Pasadena, California.

 

NASA hopes to land the water-analysing probe on flat ground with few or no rocks at a Martian latitude equivalent to northern Alaska on Earth.

 

The mission

 

Upon reaching Mars, Phoenix will use a heat shield, parachutes and thruster rockets to gently lower itself onto frozen soil, which is believed to cover a thick layer of water ice.

 

The solar-powered craft is equipped with a 2.35 metre robotic arm that will enter vertically into the soil, aiming to strike the icy crust that is believed to lie within a few inches of the surface.

 

A NASA graphic depicts Phoenix a moment
before its 2008 touchdown [AFP]

It is equipped with a drill and other instruments, to bore down into the ground and retrieve soil and ice samples for analysis.

 

The work will be done within the body of the lander.

 

Phoenix's lab includes eight ovens to bake samples so that a gas sniffer can detect vaporized gases.

   

The experiment should tell scientists several things about Mars' water, including whether it once was liquid and whether it contains any organic molecules.

 

Both conditions would substantially increase the chances that Mars was suitable for life to develop.

   

Unlike the Viking missions of the mid-1970s, Phoenix's goal is not to search for life directly but rather to ascertain if the conditions on Mars were or are suitable for indigenous microbial life to take root.