Do you remember NASA’s twin lunar spacecraft Ebb and Flow? They were sent to orbit the moon at the beginning of the year to scan it from “crust to core.”

They have finished their primary mission earlier than expected because the NASA team has analyzed the data the twins have sent back with rapid precision. The GRAIL mission sent back over 99.99 percent of the information that could have possibly been collected. The agency is chuffed about the results.

“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, the principal investigator of GRAIL at MIT in Cambridge, Massachusetts. "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."

In March Ebb and Flow began 89 days of non-stop work. The twins collected data three times with their individual Lunar Gravity Ranging systems. The systems then sent radio signals back that NASA scientists used to make a high-resolution map of the moon's gravitational field.

Yesterday, the instruments on Ebb and Flow were shut down at 10 a.m. PDT after the last data set was transmitted. The instruments are scheduled to stay off until August 30th when the next phase of the mission to examine the moon’s gravity field in more detail will begin. The spacecrafts’ current flying altitude will be cut in half bringing Ebb and Flow to the lowest but still safest distance for the mission’s purposes.

Joe Beerer, GRAIL's mission manager, joked about how close the twins will be to the moon’s topographical features: "If Ebb and Flow had feet, I think by reflex they'd want to pull them up every time they fly over a mountain."

That phase is expected to conclude in the beginning of December.

NASA’s Jet Propulsion Laboratory in Pasadena built the spacecraft to withstand the upcoming affects of the lunar eclipse. The sudden changes in temperature and darkness are not expected to affect the twins.

As for the MoonKAM over 70,000 student directed images have been captured by cameras on Ebb and Flow through San Diego’s Sally Ride Science.

In other NASA news, tomorrow the agency will prepare for the return of Dragon with live coverage starting at 12:30 a.m PDT. Dragon is expected to land in the Pacific Ocean at 8:44 a.m. PDT off the California coast.