NASA Prepares Probes For Suicide Mission 65
Press2ToContinue writes "According to a NASA news release, 'Twin lunar-orbiting NASA spacecraft that have allowed scientists to learn more about the internal structure and composition of the moon are being prepared for their controlled descent and impact on a mountain near the moon's north pole at about 2:28 p.m. PST (5:28 p.m. EST) Monday, Dec. 17. Ebb and Flow, the Gravity Recovery and Interior Laboratory (GRAIL) mission probes, are being sent purposely into the lunar surface because their low orbit and low fuel levels preclude further scientific operations. The duo's successful prime and extended science missions generated the highest resolution gravity field map of any celestial body. The map will provide a better understanding of how Earth and other rocky planets in the solar system formed and evolved. Both spacecraft will hit the surface at 3,760 mph (1.7 kilometers per second). No imagery of the impact is expected because the region will be in shadow at the time.' That's too bad; observing the impacts could provide valuable feedback. For example, a spectrographic analysis of the impact dust cloud could reveal additional density and compositional element information for the lunar polar surfaces."
Emily Lakdawalla at the Planetary Society has more information about the violent end to GRAIL's mission. If the probes were going to hit the surface of the Moon vertically, they would probably leave a crater about 3 or 4 meters in diameter. However, they are actually coming in at a very slight angle: 1.5 degrees from the horizontal, though the mountain itself has a 20-degree slope. Despite the darkness at the impact site, NASA will attempt to monitor the crashes using the Lunar Reconnaissance Orbiter.
Re:Why not to fly it out of the solar system? (Score:4, Informative)
NASA is not showing much of a sense of humor here.
On a very personal note, I wish they'd fly it out of the solar system, in the hopes that it might eventually land on a planet somewhere after drifting through space for a few billion years.
Because, who knows... maybe a few bacteria currently contaminate the probe, survive the drift through space, and end up finding their new planet hospitable. Or more fun yet, it could land within the reach of pre-modern civilization somewhere [imdb.com].
These probes don't have enough fuel to get back to earth, let alone escape the sun's gravity well.
Re:Why not to fly it out of the solar system? (Score:5, Informative)
We don't have enough fuel to actually send these things anywhere but down. As for why we don't just leave them there, usually satellites are usually decommissioned when they run out of some resource. For commercial satellites, it's usually the fuel used to maneuver, which means that it will no longer be able to doge debris so it's best to ditch them there, but for scientific applications, we often have a tank of liquid He or N2 somewhere used to cool an instrument. When that tank runs out, you have to ask if the other sensors are worthwhile to keep which occasionally they are.
If the probe is worthless, it'll just add to the satellite debris and 200 years from now it'll be a problem. But these things have a lot of kinetic energy and we really don't know what's even a foot underground on the moon so you might as well crash it and look to see what you find. As for why we're doing it at night, the moon has a temperature swing of over 200 degrees between day and night, we don't want any volatile compounds to evaporate before we get a chance to look.
Re:IS this part of the NASA outreach (Score:4, Informative)
Where is -1 offensive when you need it ?
There are two good moderations for that: troll, and flamebait. We, on the other hand, are -1 offtopic.
Re:Why not to fly it out of the solar system? (Score:1, Informative)
While it's not possible, I WISH one would hit your house and the other would hit GP's, as your punishment for both being so scientifically illiterate.
They're deep in the bottom of a bloody gravity well WITHOUT ENOUGH FUEL TO KEEP MAKING TINY CORRECTIONS IN THEIR ORBIT, so where in hell do you morons think they'll get the delta-v to leave the lunar AND TERRAN grav wells and "drift around the solar system", or even to leave the lunar grav well to strike GP's house (presumably on Earth)?! They're crashing on the moon whether deliberately or not; they can't get anywhere else.
Re:IS this part of the NASA outreach (Score:2, Informative)
This has to be the cleverest joke I have seen on /. in a long time.
Yes, stereotyping a large portion of the world population because of the actions of miniscule percentage of it is funny and clever as hell. By the way, nice propeller hat there, nerd. When are you going to move out of mom's basement? I bet you get invited to all the cool parties. See how clever I am? x_x