Article Posted on : - May 20, 2011

Artist concept of GRAIL mission. GRAIL will fly twin spacecraft in tandem orbits around the moon for several months to measure its gravity field in unprecedented detail. Photo: NASA/JPL.

PASADENA, CALIFORNIA (BNS): NASA's two Gravity Recovery And Interior Laboratory (Grail) spacecraft have completed all assembly and testing prior to shipment to Florida.

Grail-A and Grail-B spacecraft underwent an 11-day-long test that simulated many of the flight activities they will perform during the mission, all while being exposed to the vacuum and extreme hot and cold that simulate space.

The Grail mission is scheduled for launch late this summer. The Grail-A and Grail-B spacecraft will fly in tandem orbits around Earth's moon for several months to measure its gravity field in unprecedented detail.

As they fly over areas of greater and lesser gravity, caused both by visible features such as mountains and craters and by masses hidden beneath the lunar surface, they will move slightly toward and away from each other.

An instrument aboard each spacecraft will measure the changes in their relative velocity very precisely, and scientists will translate this information into a high-resolution map of the Moon's gravitational field.

The mission will also answer longstanding questions about the moon and provide scientists with a better understanding of how Earth and other rocky planets in the solar system formed, according to a news report by NASA's Jet Propulsion Laboratory.

Grail mission will create the most accurate gravitational map of the Moon to date, improving our knowledge of near-side gravity by 100 times and of far-side gravity by 1000 times.

GRAIL is a mission in NASA's Discovery Program of solar system investigations. GRAIL will begin its work at the Moon in 2012.