Lunar GRAIL Spacecraft Ahead of Schedule with Moon Mission

According to a recent statement from the nation’s space agency, the recent GRAIL mission to study the moon in greater detail than ever before completed one phase of its mission ahead of schedule.

The GRAIL mission, which stands for Gravity Recovery and Interior Laboratory is a NASA lunar mission which examines the moon “from crust to core.” The unprecedented detail obtained about the internal structure and evolution of the moon from the mission is expected to increase our knowledge of how Earth and its rocky neighbors in the inner solar system developed.

The prime mission, during which the twin probes named Ebb and Flow spent a period of 89 days in orbit using a Lunar Gravity Ranging System onboard to create a high-resolution map of the moon’s gravitational field, was completed earlier than expected. Now the two probes are gearing up for extended science operations which will begin at the end of August and run through December.

“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.

For the next phase, known as the extended mission, the spacecraft will drop down to about ½ of their current orbital height in order to take an even closer look at the moon’s gravity field.

“Orbiting at an average altitude of 14 miles (23 kilometers) 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.”

In addition to the hard scientific data collected by the GRAIL probes, the GRAIL’s MoonKAM (Moon Knowledge Acquired by Middle school students) education and public outreach program has collected some 70,000 student images of the moon. 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.