NASA’s Lunar Prospector probe hurtled on course Wednesday toward a weekend rendezvous with the moon. The spacecraft’s communications with Earth were steady and clear, its five science instruments successfully activated.
The 660-pound probe should fall within the grasp of the moon’s weak gravity field late Saturday.
The first of three lengthy braking maneuvers, to place the probe on a polar orbit around the moon, is scheduled for 4 a.m. Sunday.
The last of the maneuvers early Tuesday should steer Lunar Prospector in a 63-mile-high circular orbit. Science operations could begin by midday.
“I’m absolutely thrilled. We are on our way,” said mission manager Scott Hubbard of NASA’s Ames Research Center in California.
The spacecraft lifted off on its five-day voyage late Tuesday from Cape Canaveral, Fla., partially circling the Earth before successfully blasting out of orbit on a course to the moon.
Initial communications difficulties were blamed on an unsatisfactory orientation of the spacecraft, which kept Lunar Prospector’s dishlike antenna from pointing toward Earth.
After the probe was reoriented, three 8-foot-long extension booms carrying the spacecraft’s five instruments were extended and each of the devices was activated, said Marcie Smith, Lunar Prospector’s mission operations manager.
The $63 million mission is the National Aeronautics and Space Administration’s first to the moon since the success of its human Apollo explorations, which concluded in December 1972.
Two of Lunar Prospector’s instruments will search for evidence of frozen water deep in the recesses of craters on the south pole, a finding that could hasten establishment of a human lunar base.
The probe’s five scanning sensors will attempt to chart the mineral composition of the moon’s surface.
Prospector also will look for seismic activity first noted by the Apollo missions, evidence of a magnetic field and a lunar core.