WASHINGTON, December 17 (RIA Novosti) Two NASA moon probes, designed to help scientists learn more about the internal structure and composition of the moon, will be intentionally crashed into a mountain near the moon's North Pole on Monday, the United States space agency said.
Mission engineers need to guide the twin Gravity Recovery and Interior Laboratory (GRAIL) probes known as Ebb and Flow down because they have run out of fuel to keep them in lunar orbit, NASA officials said in a statement.
"Our lunar twins may be in the twilight of their operational lives, but one thing is for sure, they are going down swinging," said GRAIL project manager David Lehman of NASA's Jet Propulsion Laboratory in Pasadena, California.
The washing machine-size probes are scheduled to crash into the moon about 20 seconds apart at 5:28 p.m. EST (10:28 p.m. GMT) at a speed of 3,760 mph (6,051 kph).
The event will be broadcast on NASA TV and streamed live on the agency's website beginning at 5 p.m. EST (10:00 p.m. GMT), giving viewers around the world a behind-the-scenes look at the event, including interviews with members of the GRAIL team.
Images of the actual crash won’t be available because the region on the moon where the impact is expected to take place will be in shadows at the time, NASA officials said.
The $496 million GRAIL mission was launched in September 2011, with Ebb and Flow flying in formation around the moon since this past January. According to media reports, the probes completed their main task of mapping lunar gravity between March and May of this year.
Ebb and Flow will conduct one final experiment before their mission ends, NASA officials said.
“They will fire their main engines until their propellant tanks are empty to determine precisely the amount of fuel remaining in their tanks,” allowing NASA’s engineers to certify fuel consumption computer models which will help improve predictions of fuel needs for future missions, NASA officials said.
