NASA to study moon's structure, evolution

WASHINGTON, Dec. 11 (UPI) -- The U.S. space agency announced plans for a study to determine the moon's structure and its evolutionary history.

The National Aeronautics and Space Administration's Associate Administrator for Science Alan Stern said the $375 million Gravity Recovery and Interior Laboratory, or GRAIL, mission is to be launched in 2011.

NASA said GRAIL will fly twin spacecraft in tandem orbits around the moon for several months to measure its gravity field in unprecedented detail. The mission is also expected to provide scientists with a better understanding of how Earth and other rocky planets in the solar system formed.

Stern said scientists will use the gravity field information from the two satellites to reveal the moon's subsurface structures and, indirectly, its thermal history.

"As NASA moves forward with exploration endeavors, our lunar science missions will be the light buoy leading the path for future human activities," said Jim Green, director of NASA's planetary division.

NASA's Jet Propulsion Laboratory will manage the GRAIL mission. The spacecraft will be built by Lockheed Martin Space Systems.