"The surface of the Earth is the shore of the cosmic ocean... Recently, we've managed to wade a little way out, and the water seems inviting." - Carl Sagan
Ground controllers at NASA’s Ames Research Center in Moffett Field, Calif., have confirmed that NASA’s Lunar Atmosphere and Dust Environment Explorer (LADEE) spacecraft impacted the surface of the moon, as planned, between 9:30 and 10:22 p.m. PDT Thursday, April 17.
LADEE lacked fuel to maintain a long-term lunar orbit or continue science operations and was intentionally sent into the lunar surface. The spacecraft’s orbit naturally decayed following the mission’s final low-altitude science phase.
During impact, engineers believe the LADEE spacecraft, the size of a vending machine, broke apart, with most of the spacecraft’s material heating up several hundred degrees – or even vaporizing – at the surface. Any material that remained is likely buried in shallow craters.
"At the time of impact, LADEE was traveling at a speed of 3,600 miles per hour – about three times the speed of a high-powered rifle bullet," said Rick Elphic, LADEE project scientist at Ames. "There’s nothing gentle about impact at these speeds – it’s just a question of whether LADEE made a localized craterlet on a hillside or scattered debris across a flat area. It will be interesting to see what kind of feature LADEE has created."
In early April, the spacecraft was commanded to carry out maneuvers that would lower its closest approach to the lunar surface. The new orbit brought LADEE to altitudes below one mile (two kilometers) above the lunar surface. This is lower than most commercial airliners fly above Earth, enabling scientists to gather unprecedented science measurements.
On April 11, LADEE performed a final maneuver to ensure a trajectory that caused the spacecraft to impact the far side of the moon, which is not in view of Earth or near any previous lunar mission landings. LADEE also survived the total lunar eclipse on April 14 to 15. This demonstrated the spacecraft’s ability to endure low temperatures and a drain on batteries as it, and the moon, passed through Earth’s deep shadow.
In the coming months, mission controllers will determine the exact time and location of LADEE’s impact and work with the agency’s Lunar Reconnaissance Orbiter (LRO) team to possibly capture an image of the impact site. Launched in June 2009, LRO provides data and detailed images of the lunar surface.