US space scientists were to attempt to land a US$420 million spacecraft near Mars’ frigid north pole yesterday, but were concerned that the odds for success were less than 50 percent.
“I’m a little nervous on the inside,” scientist Peter Smith said on Saturday of the planned landing of the Phoenix probe, due late the following day.
Mission specialists were reviewing data to decide whether a course-correction would be needed eight hours ahead of touch-down to keep the Phoenix on track for landing in a relatively rock-free, flat region in the Mars arctic after its 679 million kilometer journey from Earth.
An earlier trajectory correction was scrubbed on Saturday because “Phoenix is so well on course for its Sunday-evening landing on an arctic Martian plain that the team decided it was not necessary,” said NASA’s Jet Propulsion Laboratory in Pasadena, California, which controls the mission.
Phoenix was expected to enter the Martian atmosphere late yesterday at about 21,000kph and rely on its thermal shield, then a parachute followed by a bank of pulse thrusters, to slow down to 8kph ahead of touchdown on the circumpolar region.
Phoenix will become the first spacecraft to land on the Martian arctic surface, digging into the polar ice in a new three-month mission searching for signs of life.
“We are going to a place on the planet that is unexplored and very exciting,” Smith, Phoenix principal investigator at the University of Arizona, told reporters on Saturday.
But the nearly five decades of Mars exploration are fraught with failures — about half of the three dozen tries have crashed, disappeared or missed the planet altogether.
Given the long distance, NASA’s laboratory will have to wait an agonizing 15 minutes for the radio signal confirming the safe landing to reach Earth.
One minute after Phoenix confirms arrival, its radio will go silent for 20 minutes to save its batteries before deploying its two solar antennas. Its first images will reach Earth only after two hours.