What does a longtime space agency do with lunar research satellites when they have run out of fuel? If you’re the space geeks at National Aeronautics and Space Administration (NASA) Jet Propulsion Lab (JPL) in Pasadena, California, you do something unforgettable: You crash them into moon!
Ebb and Flow are appliance-sized probes (or spacecraft) in NASA’s Gravity Recovery and Interior Laboratory (GRAIL) program. The GRAIL lunar science mission, part of NASA’s Discovery Program, employs high-tech tools with which to produce a high-quality gravitational field map of the Moon, to help better determine its interior structure.
The GRAIL mission placed two spacecraft–Grail A and B, which are more commonly known as Ebb and Flow–into the same orbit around the Moon.
Ebb and Flow launched on 10 September 2011 onboard a Delta II rocket—specifically, the 7920H-10 from United Launch Alliance (ULA) in Centennial, Colo. ULA is a joint venture of Lockheed Martin and The Boeing Company.
Ebb separated from the Delta II rocket roughly nine minutes after launch, and Flow followed suit approximately 16 minutes after launch. Ebb entered orbit on 31 December 2011; Flow entered orbit a day later on New Year’s Day, 1 January 2012. Since that time, they have been performing as expected and on-board electronics have been recording and delivering data to awaiting NASA engineers and scientists.
Ebb and Flow have enjoyed a year-long stint in orbit, but that is about to end with a bang. This geek cannot think of anything more positive or exciting to focus on this week, and is excited for the explosive event.