Space

May 30, 2012

NASA lunar spacecraft complete prime mission ahead of schedule

An artist’s depiction of the twin spacecraft that comprise NASA’s Gravity Recovery And Interior Laboratory (GRAIL) mission. During the GRAIL mission’s science phase, spacecraft (Ebb and Flow) transmit radio signals precisely defining the distance between them as they orbit the moon in formation. As the two fly over areas of greater and lesser gravity caused by both visible features, such as mountains and craters, and masses hidden beneath the lunar surface, the distance between the two spacecraft will change slightly. Mission scientists use this information to create a high-resolution map of the moon’s gravitational field. The data will allow scientists to understand what goes on below the lunar surface.

A NASA mission to study the moon from crust to core has completed its prime mission earlier than expected.

The mission team of NASA’s Gravity Recovery and Interior Laboratory mission, with twin probes named Ebb and Flow, is now preparing for extended science operations starting Aug. 30 and continuing through Dec. 3, 2012.

The GRAIL mission has gathered unprecedented detail about the internal structure and evolution of the moon. This information will increase our knowledge of how Earth and its rocky neighbors in the inner solar system developed into the diverse worlds we see today.

Since March 8, the spacecraft have operated around the clock for 89 days. From an orbit that passes over the lunar poles, they have collected data covering the entire surface three times. An instrument called the Lunar Gravity Ranging System onboard each spacecraft transmits radio signals that allow scientists to translate the data into a high-resolution map of the moon’s gravitational field. The spacecraft returned their last data set of the prime mission today. The instruments were turned off at 1 p.m., EDT, when the spacecraft were 37 miles above the Sea of Nectar.

“Many of the measurement objectives were achieved from analysis of only half the primary mission data, which speaks volumes about the skill and dedication of our science and engineering teams,” said Maria Zuber, principal investigator of GRAIL at the Massachusetts Institute of Technology in Cambridge. “While there is a great deal of work yet to be done to achieve the mission’s science, it’s energizing to realize that what we traveled from Earth to the moon for is right here in our hands.”

“GRAIL delivered to Earth over 99.99 percent of the data that could have been collected, which underscores the flawless performance of the spacecraft, instrument and the Deep Space Network,” said Zuber.

Both spacecraft instruments will be powered off until Aug. 30. The spacecraft will have to endure a lunar eclipse on June 4. The eclipse and the associated sudden changes in temperature and the energy-sapping darkness that accompanies the phenomena were expected and do not concern engineers about the spacecraft’s health.

“Before launch, we planned for all of GRAIL’s primary mission science to occur between lunar eclipses,” said David Lehman, project manager of GRAIL from NASA’s Jet Propulsion Laboratory in Pasadena, Calif. “But now that we have flown Ebb and Flow for a while, we understand them and are confident they can survive these eclipses in good shape.”

The extended mission goal is to take an even closer look at the moon’s gravity field. To achieve this, GRAIL mission planners will halve their current operating altitude flying at the lowest altitude that can be safely maintained.

“Orbiting at an average altitude of 14 miles during the extended mission, the GRAIL twins will be clearing some of the moon’s higher surface features by about 5 miles (8 kilometers),” said Joe Beerer, GRAIL’s mission manager. “If Ebb and Flow had feet, I think by reflex they’d want to pull them up every time they fly over a mountain.”

Along with mission science, GRAIL’s MoonKAM (Moon Knowledge Acquired by Middle school students) education and public outreach program is also extended. To date over 70,000 student images of the moon have been obtained. The MoonKAM program is led by Sally Ride, America’s first woman in space, and her team at Sally Ride Science in collaboration with undergraduate students at the University of California in San Diego.

The GRAIL mission is managed by JPL for NASA’s Science Mission Directorate in Washington. The mission is part of the Discovery Program managed at NASA’s Marshall Space Flight Center in Huntsville, Ala. NASA’s Deep Space Network is an international network of antennas that supports interplanetary spacecraft missions and radio and radar astronomy observations for the exploration of the solar system and the universe. The network also supports selected Earth-orbiting missions. Lockheed Martin Space Systems in Denver built the spacecraft.




All of this week's top headlines to your email every Friday.


 
 

 

Headlines April 1, 2015

News: Iranian aircraft buzzed U.S. Navy helo in Persian Gulf - An Iranian aircraft buzzed a Navy helicopter operating in the Persian Gulf earlier this month, a U.S. military official said March 31. Active duty suicides up in 2014 - Suicides among active duty members of the military increased in 2014, though reservists and members of the...
 
 

News Briefs April 1, 2015

Germany, France, Italy plan to develop military drones Germany and France plan to work together with Italy to develop military surveillance drones that could also carry weapons. French President Francois Hollande said after meeting German Chancellor Angela Merkel March 31 that it is important for Europe to be independent in both manufacturing drones and in...
 
 
Northrop Grumman photograph

AirRobot, Northrop Grumman Remotec sign distribution agreement for unmanned aerial systems

Northrop Grumman photograph An AirRobot unmanned aerial system flies at Fort Benning, Ga.. Northrop Grumman Remotec is the sole reseller of the systems to law enforcement and first responders under a distribution agreement sign...
 

 

Raytheon awarded $528 million AMRAAM contract

Raytheon has been awarded a $528,797,459 fixed-price incentive, firm target contract modification for Advanced Medium Range Air-to-Air Missiles. Raytheon will provide AMRAAM Lot 29 missiles and other AMRAAM system items. This contract involves foreign military sales. Work will be performed in Tucson and is expected to be complete by January 2018. This award was booked...
 
 

Raytheon, DRS team for Army’s third Generation IFLIR B-Kit

Building on their combined platform integration experience, Raytheon and DRS Technologies have entered into a teaming agreement for the U.S. Army’s 3rd Generation Improved Forward Looking Infrared program B-Kit “Raytheon and DRS have teamed to provide an IFLIR solution that provides our military supremacy in reconnaissance, surveillance and target acquisition,” said Dr. Taylor...
 
 

U.S. Air Force awards Raytheon $91.5 million for MALD-J

Raytheon Company received a $91.5 million U.S. Air Force contract modification award for the Miniature Air Launched Decoy Jammer missile. The contract modification is for Lot 8. Work will be performed in Tucson and is expected to be complete by June 2017. This award was booked in the first quarter 2015. MALDÆ is a state-of-the-art,...
 




0 Comments


Be the first to comment!


Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <strike> <strong>