WASHINGTON (AFP) — After a nine-month journey through space, the US probe Phoenix will land on the arctic surface of Mars on Sunday to dig for ice in a new quest for signs of life on the Red Planet.
NASA's 420-million-dollar probe will become the first spacecraft to land on the Martian arctic and will stay there for a three-month mission.
After traveling 679 million kilometers through the cosmos, Phoenix will enter the top of the Martian atmosphere at around 2331 GMT, zipping at 21,000 kilometers per hour to begin a perilous descent that will end with a soft landing seven minutes later.
But the US space agency's Jet Propulsion Laboratory (JPL) in Pasadena, California, which controls the mission, will have to wait an agonizing 15 minutes for the radio signal confirming the safe landing to reach Earth.
"This is not a trip to grandma's house. Putting a spacecraft safely on Mars is hard and risky," said Ed Weiler, associate administrator for NASA's Science Mission Directorate.
Since Mars exploration began in the 1970s, more than half, or 55 percent, of probes sent to the Red Planet failed to reach their destination.
Like previous Mars landers, Phoenix is equipped with a thermal shield to slow its entry into the atmosphere and will deploy a parachute to slow its speed.
The probe will then fire up its thrusters to slow its descent to eight km/h (five m/ph) and land on its three legs on the circumpolar region known as Vastitas Borealis -- akin to northern Canada in Earth latitude.
One minute after Phoenix confirms arrival, its radio will go silent for 20 minutes to save its batteries before deploying its two solar antennas.
The first images of Phoenix will reach Earth two hours later.
"The Phoenix mission not only studies the northern permafrost region, but takes the next step in Mars exploration by determining whether this region, which may encompass as much as 25 percent of the Martian surface, is habitable (for future manned missions to Mars)," said Peter Smith, Phoenix principal investigator at the University of Arizona.
The probe will work under harsh conditions with temperatures ranging between minus 73 and minus 33 degress Celsius.
NASA wants to assess whethern the Martian arctic ever had conditions favorable to microbial life. The probe will also help determine whether if a primitive lifeform was ever or is still present on Mars.
Phoenix is equipped with a camera and a 2.35-meter (7.7-foot) robotic arm that can dig as deep as one meter to find ice and heat up samples to detect water.
The robot's instruments can detect carbon and hydrogen molecules, essential elements of life.
With its two solar panels unfurled, Phoenix is five meters wide and 1.52 meters long. It weights 350 kilograms (772 lbs), including 55 pounds of scientific instruments.
Phoenix will be latest ambitious mission to explore Mars.
The US Mars Odyssey orbiter detected vast quantities of hydrogen on the planet's surface in 2002, a sign that its polar regions are covered in ice.
The roving robots Spirit and Opportunity, which have roamed the Martian surface's equator for three years, have also discovered signs of past water.
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