The current mission aims to answer that question and strip away the last shrouds of mystery from the moon.
The lunar orbiter carries seven instruments, among them a set of cameras that can resolve features as small as 18 inches across, the size of a small boulder.
A laser altimeter will bounce beams off the surface to create a detailed view of the landscape -- mountains, ridges and valleys. An instrument dubbed CRaTER will measure the radiation environment. NASA has long known that exposure to cosmic and solar radiation is a hazard for anyone living on the lunar surface.
"If we're going to stay on the moon a long time, we're going to have to figure out how to protect ourselves," Tooley said.
The Lunar Reconnaissance Orbiter will have a good chance of finding water, if it's there. But sometimes, nothing beats getting your hands dirty, and that's where the Lunar Crater Observation and Sensing Satellite comes in.
After the orbiter parts company with the satellite and rocket shortly after launch, the crater-busting combo will go into a looping Earth orbit to line up a space-based knockout blow to the moon. The punch will be delivered by the second-stage of the Atlas V rocket (by then devoid of fuel), called a Centaur. After sling-shotting around the Earth to gain momentum and achieve the highest possible angle for its plunge into the moon, the SUV-sized Centaur will barrel into the targeted crater on the morning of Oct. 8 at about 5,600 mph. It will shatter any surface ice and send up a huge plume of dust.
Four minutes after the collision, the accompanying satellite will fly through the debris to take measurements of the chemical composition. Any water blasted out of the crater will quickly decompose. But the satellite carries among its nine instruments a set of visible light and infrared cameras, as well as spectrometers, specifically designed to spot the decomposing chemicals.
After flying through the cloud, the satellite will crash into the lunar surface some distance away. Miles above, watching the drama unfold, will be the reconnaissance orbiter.
And a bit farther away, down on terra firma, hobbyists by the thousands will be training their telescopes on the moon's underbelly.
NASA still hasn't decided which crater to pummel. It must be shallow enough that the material blasted out can rise above the rim so the spacecraft can fly through it to take measurements, Colaprete said.
NASA won't settle on a target until 30 days before impact, when it will have the orbiter's measurements to help guide the choice.
It could take months to unravel what the spacecraft finds. But if it turns up unequivocal proof of water on a purportedly dead world, no one is going to sit on that bombshell.
"If we hit a high concentration of water, we will report that as soon as we can," Colaprete said.
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john.johnson@latimes.com
