The US spacecraft Mars Polar Lander, which is designed to search for water, was approaching Mars yesterday in preparation for a landing there a week from now.
Hurtling toward the planet at 4.8 km per second, the spacecraft had to cover fewer than five million km before its landing scheduled for Friday next.
Launched 11 months ago from the Kennedy Space Centre in Florida, the probe has a dual task: to land softly on Mars and to release two mini-probes which will fly separately to different locations and then drill themselves to a depth of 1 metre into the planet's surface.
US space engineers are monitoring the Lander's performance following the loss in September of the Mars Polar Orbiter which is believed to have crashed after it was sent on a wrong orbit.
Scientists have recently detected a defect in an engine used to slow the descent of the spacecraft about 2.5 km from the surface of Mars.
Meanwhile, another US spacecraft, the Mars Global Surveyor, is circling the planet, taking pictures of it.