Twin Grail spacecraft begin collecting lunar science data

March 7, 2012
Artist concept of GRAIL mission. GRAIL will fly twin spacecraft in tandem orbits around the moon to measure its gravity field in unprecedented detail. Image credit: NASA/JPL

(PhysOrg.com) -- NASA's Gravity Recovery And Interior Laboratory (GRAIL) spacecraft orbiting the moon officially have begun their science collection phase. During the next 84 days, scientists will obtain a high-resolution map of the lunar gravitational field to learn about the moon's internal structure and composition in unprecedented detail. The data also will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved.

"The initiation of is a time when the team lets out a collective sigh of relief because we are finally doing what we came to do," said Maria Zuber, principal investigator for the GRAIL mission at the Massachusetts Institute of Technology in Cambridge. "But it is also a time where we have to put the coffee pot on, roll up our sleeves and get to work."

The GRAIL mission's twin, washing-machine-sized spacecraft, named Ebb and Flow, entered on New Year's Eve and New Years Day. GRAIL's science phase began yesterday at 8:15 p.m. EST (5:15 p.m. PST). During this mission phase, the spacecraft will transmit precisely defining the distance between them. As they fly over areas of greater and lesser gravity caused by visible features such as mountains, craters and masses hidden beneath the lunar surface, the distance between the two spacecraft will change slightly. Science activities are expected to conclude on May 29, after GRAIL maps the of the moon three times.

"We are in a near-polar, near-circular orbit with an average altitude of about 34 miles (55 kilometers) right now," said David Lehman, GRAIL project manager from NASA's Jet Propulsion Laboratory (JPL) in Pasadena, Calif. "During the science phase, our spacecraft will orbit the moon as high as 31 miles (51 kilometers) and as low as 10 miles (16 kilometers). They will get as close to each other as 40 miles (65 kilometers) and as far apart as 140 miles (225 kilometers)."

Previously named GRAIL A and B, the names Ebb and Flow were the result of a nation-wide student contest to choose new names for the . The winning entry was submitted by fourth graders from the Emily Dickinson Elementary School in Bozeman, Mont. Nearly 900 classrooms with more than 11,000 students from 45 states, Puerto Rico and the District of Columbia, participated in the contest.

Explore further: GRAIL moon mission in final preparations for September launch

More information: www.nasa.gov/grail

Related Stories

NASA's moon twins going their own way

October 7, 2011

NASA's Gravity Recovery And Interior Laboratory (GRAIL)-B spacecraft successfully executed its first flight path correction maneuver Wednesday, Oct. 5. The rocket burn helped refine the spacecraft's trajectory as it travels ...

NASA's GRAIL-A spacecraft 24 hours away from Moon

December 31, 2011

(PhysOrg.com) -- NASA's Gravity Recovery And Interior Laboratory (GRAIL)-A spacecraft is within 24 hours of its insertion burn that will place it into lunar orbit. At the time the spacecraft crossed the milestone at 1:21 ...

Twin Grail spacecraft reunite in lunar orbit

January 2, 2012

(PhysOrg.com) -- The second of NASA's two Gravity Recovery And Interior Laboratory (GRAIL) spacecraft has successfully completed its planned main engine burn and is now in lunar orbit. Working together, GRAIL-A and GRAIL-B ...

Recommended for you

Rosetta captures comet outburst

August 25, 2016

In unprecedented observations made earlier this year, Rosetta unexpectedly captured a dramatic comet outburst that may have been triggered by a landslide.

ALMA finds unexpected trove of gas around larger stars

August 25, 2016

Astronomers using the Atacama Large Millimeter/submillimeter Array (ALMA) surveyed dozens of young stars—some Sun-like and others approximately double that size—and discovered that the larger variety have surprisingly ...

35 years on, Voyager's legacy continues at Saturn

August 25, 2016

Saturn, with its alluring rings and numerous moons, has long fascinated stargazers and scientists. After an initial flyby of Pioneer 11 in 1979, humanity got a second, much closer look at this complex planetary system in ...

Rocky planet found orbiting habitable zone of nearest star

August 24, 2016

An international team of astronomers including Carnegie's Paul Butler has found clear evidence of a planet orbiting Proxima Centauri, the closest star to our Solar System. The new world, designated Proxima b, orbits its cool ...

2 comments

Adjust slider to filter visible comments by rank

Display comments: newest first

hyongx
4.5 / 5 (2) Mar 07, 2012
Long-term survival of humanity depends on the establishment of self-sustaining colonies on the moon. A proof-of-principle that our species can continue after Earth has become entirely toxic and too hot.
First, extracting water from the soil and using either fusion or solar energy is essential. Thanks NASA for pioneering this essential investigation.
roboferret
not rated yet Mar 08, 2012
Long-term survival of humanity depends on the establishment of self-sustaining colonies on the moon. A proof-of-principle that our species can continue after Earth has become entirely toxic and too hot.
First, extracting water from the soil and using either fusion or solar energy is essential. Thanks NASA for pioneering this essential investigation.


If even the worst predictions for global warming and pollution come true, the Earth will still be vastly more hospitable than the Moon. The most inhospitable environments on earth are lush oases compared to the most benign environments in our solar system (thus discovered). Bunkers are a more preferable option than a moon-base for anything less than a surface-melting asteroid collision, if the survival of the species are your concern.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.