NASA Mission to the Moon

LOS ANGELES –  The cruise to the moon took 3 1/2 months and covered 2 1/2 million miles -- far longer than the direct three-day flight by Apollo astronauts.
Over the New Year's weekend, a pair of NASA spacecraft arrived back-to-back at their destination in the first mission devoted to studying lunar gravity.
Mission controllers at the NASA Jet Propulsion Laboratory did not toast with champagne -- there's a no-alcohol policy on campus -- but several belatedly heralded the new year by with noisemakers.

"We can start celebrating the new year now," project manager David Lehman said Sunday after attending a post-mission fete where cake and sparkling cider were served.
The tricky arrivals occurred 24 hours apart. The drama unfolded on New Year's Eve when Grail-A flew over the south pole, fired its engine and dropped into lunar orbit. Its twin Grail-B repeated the maneuvers on New Year's Day.
Cheers and applause filled mission control when each probe signaled it was healthy and circling the moon.
"Everything worked much better than I hoped," Lehman said.
The moon has long been an object of fascination. Galileo spotted mountains and craters when he peered at it through a telescope. Poets and songwriters looked to the moon as a muse.
Since the late 1950s, more than 100 missions launched by the United States, Soviet Union, Japan, China and India have targeted Earth's companion. NASA flew six Apollo missions that landed twelve men on the lunar surface and brought back more than 800 pounds of rock and soil samples.
Despite all the visits, the moon remains mysterious. Mission chief scientist Maria Zuber of the Massachusetts Institute of Technology said researchers know more about Mars, which is farther away from the Earth, than the moon.
One of the enduring puzzles is its lopsided shape with the far side more hilly than the side that always faces Earth. Research published earlier this year suggested that our planet once had two moons that crashed early in the solar system's history and created the moon that hangs in the sky today.
Scientists expect to learn more about how the celestial body formed using Grail's gravity measurements that will indicate what's below the surface.
Since the washing machine-size Grail probes -- short for Gravity Recovery And Interior Laboratory -- were squeezed on a small rocket to save on costs, it lengthened the trip and took them 30 times longer to reach the moon than the Apollo astronauts.
Previous spacecraft have attempted to study the moon's gravity -- about one-sixth Earth's pull -- with mixed success. Grail was expected to give scientists the most detailed maps of the moon's uneven gravitational field and insight into its interior down to the core.
Data collection won't begin until March after the near-identical spacecraft refine their positions and are circling just 34 miles above the surface. While scientists focus on gravity, middle school students will get the chance to take their own pictures of the moon using cameras aboard the probes as part of a project headed by Sally Ride, the first American woman in space.
There's already chatter about trying to extend the $496 million mission, which was slated to end before the partial lunar eclipse in June. Scientists initially did not think the solar-powered probes would survive that long, but changed their minds during the long cruise to the moon after getting new data.
Researchers expect Grail to return a plethora of data, but that information won't be a guide to manned lunar trips anytime soon. The Obama administration last year scrapped a plan to return astronauts to the lunar surface in favor of landing on an asteroid as a stepping stone to Mars.

AFP 
WASHINGTON: The second of two NASA lunar probes on a mission to study the Moon's inner core so scientists can better understand the origins of planets went into orbit Sunday as planned, the US space agency said.

The second Gravity Recovery and Interior Laboratory (GRAIL-B) began orbiting the Moon at about 2243 GMT, according to officials at NASA's Jet Propulsion Laboratory in Pasadena, California.

GRAIL-A reached its lunar orbit on Saturday.

"NASA greets the new year with a new mission of exploration," NASA Administrator Charles Bolden said in a statement.

"The twin GRAIL spacecraft will vastly expand our knowledge of our moon and the evolution of our own planet," he said.

"We begin this year reminding people around the world that NASA does big, bold things in order to reach for new heights and reveal the unknown."

The $500-million pair of washing machine-sized satellites were launched on September 10 on a mission to map the Moon's inner core for the first time.

The spacecraft are in a near-polar elliptical orbit, traveling around the Moon in about 11.5 hours, NASA said. In the coming weeks, that orbit time will be reduced to just under two hours, it added.

Beginning in March, the two unmanned spacecraft will send radio signals that allow earth-based scientists to create a high-resolution map of the Moon's gravitational field, helping them to better understand its sub-surface features and the origins of other bodies in the solar system.

The mission should shed light on the unexplored far side of the Moon and test a hypothesis that there was once a second Moon that fused with ours.

The two spacecraft have taken three months to reach the Moon as opposed to the usual three-day journey taken by the manned Apollo missions. The longer journey allowed scientists to better test the two probes.

Scientists believe that the Moon was formed when a planet-sized object crashed into the Earth, throwing off a load of material that eventually became our planet's airless, desolate satellite.

How it heated up over time, creating a magma ocean that later crystallized, remains a mystery, despite 109 past missions to study the Moon since 1959 and the fact that 12 humans have walked on its surface. (AFP)