LOS ANGELES (AP) - The New Year’s countdown to the moon has
begun. NASA said Wednesday that its twin spacecraft were on
course to arrive back-to-back at the moon after a 3 1/2-month
journey. The Grail probes _ short for Gravity Recovery And
Interior Laboratory _ won’t land on the lunar surface. Instead,
they were poised to slip into orbit to study the uneven lunar
gravity field. Lehman said team members won’t celebrate until
both probes are safely in orbit. It’s been a long voyage for the
near-identical Grail spacecraft, which traveled more than 2.5
million miles since launching in September. Though the moon is
relatively close at about 250,000 miles away, Grail took a
roundabout way to save on costs by launching on a small rocket.
Once at the moon, the probes will spend the next two months
tweaking their positions before they start collecting data in
March. The pair will fly in formation at an altitude of 34 miles
above the surface, with an average separation of 124 miles. The
mission’s chief scientist, Mari