LADEE Makes A New Lunar Crater
NASA Completes LADEE Mission with Planned Impact on Moon’s Surface
“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.”
@LunarOrbiter Thank you! It's true – there's still loads of science data to crunch through!
— LADEE (@NASALADEE) April 18, 2014
“The spacecraft’s orbit naturally decayed following the mission’s final low-altitude science phase.”
Given the lack of atmosphere this requires a little explanation.
there are very few stable lunar orbits, due to mass concentrations (commonly called mascons), which perturb objects orbiting the moon. the final orbits of LADEE were extremely close to the lunar surface, so the effects of these perturbations built up over time until it impacted the surface.
http://science.nasa.gov/sci…
Thanks I was wondering about this too. You have to be “close enough” for that to actually put it into the Moon and I guess they were.
yes, indeed. the final 100 orbits of LADEE were less than 1 mile in altitude.
altitude is a measurement of distance above a surface, and, as such, it does not matter whether there is atmosphere, or not. Since the moon has gravity, if an object in orbit does not have sufficient velocity to maintain that orbit, it will eventually fall. Think of a weight, tied to a string. If you stop swinging the string, or slow it down to a certain point, the object will stop its path at the limit of the string.
It probably had sufficient velocity since it was in orbit, right? A weight tied to a string has air resistance and other friction, but take that away and it would keep swinging.