In an unexpected control glitch this weekend, NASA’s Lunar Crater Observation and Sensing Satellite (LCROSS) went berserk and burned up all its extra fuel.
It turns out the spacecraft had an attitude problem: A broken sensor in the LCROSS attitude control system, which keeps track of the satellite’s orientation, caused the spacecraft to repeatedly fire its thrusters and burn up about 140 kg of hydrazine propellant. Fortunately, NASA says the spacecraft was carrying more fuel than it needed and still has 50 kg left, enough to complete its mission.
If all goes well, LCROSS will release its Centaur rocket on October 9, 2009, sending the projectile hurtling at the south pole of the moon at 1.55 miles per second, about twice the speed of a bullet. Scientists hope the impact will send up a huge plume of moon debris, possibly containing ice, vapor or traces of hydrated materials that prove the existence of water on the moon.
Four minutes later, the rest of the spacecraft will follow the rocket’s path through the cloud of lunar dust, analyzing its contents and transmitting data back to Earth before the entire spacecraft crashes into the moon’s surface. NASA says the impact will generate a cloud of dust so big that we may be able to see it from Earth using an amateur telescope.
This isn’t the first time we’ve crashed rockets into extraterrestrial bodies to find out what’s inside. In 2005, NASA’s Deep Impact spacecraft sent a probe crashing into Comet Tempel 1 to study the contents of the comet’s interior. A European probe called SMART-1 crashed into the moon in 2006, and Japanese scientists crashed their Kayuga probe into the moon this June. So far, none of the missions have discovered the water LCROSS is looking for.
Image: Artist’s rendering of LCROSS launching its Centaur rocket into the moon/NASA.
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