NASA's twin spacecraft approaches moon to map gravitational field

[News_Editor]

NASA's twin spacecraft approaches moon to map gravitational field

2011-12-29 21:28:57 GMT+7 (ICT)

PASADENA, CALIFORNIA (BNO NEWS) -- The U.S. National Aeronautics and Space Administration (NASA) on Thursday announced that its twin spacecraft are on its final approach to the moon where it will work to develop a high-resolution map of its gravitational field.

The Gravity Recovery And Interior Laboratory (GRAIL) spacecraft are to study the moon from crust to core and are nearing their New Year's Eve and New Year's Day main-engine burns to place the duo in a lunar orbit.

According to NASA, the GRAIL-A spacecraft is scheduled to be placed in orbit at approximately 1:21 p.m. PST on Saturday. Its twin, GRAIL-B, is expected to enter its orbit at approximately 2:05 p.m. PST on Sunday.

The two spacecraft will transmit radio signals during its mission, precisely defining the distance between them as they orbit the moon when science collection begins.

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, the spacecraft will move slightly toward and away from each other. An instrument aboard each spacecraft will then measure the changes in their relative velocity with high precision, and scientists will translate this information into a high-resolution map of the Moon's gravitational field.

NASA said the data will allow mission scientists to understand what goes on below the surface, which will increase knowledge of how Earth and its rocky neighbors in the inner solar system developed into the diverse worlds we currently see.

The distance from Earth to the moon is approximately 250,000 miles (402,336 kilometers), but compared to NASA's Apollo crews, which took about three days to travel to the moon, the GRAIL spacecraft are taking about 30 times that long and covering more than 2.5 million miles (4 million kilometers) to get there.

The GRAIL spacecraft was launched from the Cape Canaveral Air Force Station in Florida on September 10, and the low-energy, long-duration trajectory has given mission planners and controllers more time to assess the spacecraft's health.

The path also allowed a vital component of the spacecraft's single science instrument, the Ultra Stable Oscillator, to be continuously powered for several months, which will allow it to reach a stable operating temperature long before it begins making science measurements in lunar orbit.

"This mission will rewrite the textbooks on the evolution of the moon," said Maria Zuber, GRAIL principal investigator from the Massachusetts Institute of Technology (MIT) in Cambridge. "Our two spacecraft are operating so well during their journey that we have performed a full test of our science instrument and confirmed the performance required to meet our science objectives."

-- © BNO News All rights reserved 2011-12-29

[redroo]

Annything worth mining on the the moon ?

[koheesti]

It's gotta be all about oil.

Seriously, water is probably the most important thing they can find on the moon. To have a source outside the Earth's gravitational pull would be of great benefit for future exploration. People can't go on drinking recycled urine for ever.

Edited December 30, 2011 by koheesti

[Scott]

If it's about oil, I can hardly wait to see what that pipeline looks like.