This artist's rendering depicts the Lunar Reconnaissance Orbiter circling the moon about 31 miles above its surface. Using seven science instruments, it will create a detailed map of the landscape.
This artist's rendering depicts the Lunar Reconnaissance Orbiter circling the moon about 31 miles above its surface. Using seven science instruments, it will create a detailed map of the landscape. NASA
The Lunar Crater Observation and Sensing Satellite (LCROSS) is lowered into the thermal vacuum chamber for heating and cooling tests that simulate the harsh conditions of outer space.
The Lunar Crater Observation and Sensing Satellite (LCROSS) is lowered into the thermal vacuum chamber for heating and cooling tests that simulate the harsh conditions of outer space. Northrop Grumman/NASA
LCROSS will look for water by smashing part of its rocket into a moon crater and gathering data from the plume of dust — and maybe ice — that erupts. Scientists think this plume may be visible from Earth for a short time.
LCROSS will look for water by smashing part of its rocket into a moon crater and gathering data from the plume of dust — and maybe ice — that erupts. Scientists think this plume may be visible from Earth for a short time. NASA
NASA has launched its first lunar mission in more than a decade, part of its effort to eventually return astronauts to the moon.
A rocket carrying two unmanned probes blasted off from Cape Canaveral Air Force Station in Florida on Thursday afternoon. One probe will orbit the moon and map its surface in unprecedented detail, while the other will deliberately crash into a cold, dark crater to try to find frozen water.
A Mapping Mission
Scientists already know a fair bit about the so-called "Apollo Zone," the equatorial regions of the moon visited by moonwalkers decades ago, says Craig Tooley, NASA's project manager for the Lunar Reconnaissance Orbiter. But the rest of the moon is more mysterious.
"We, at the moment, have much better maps globally of the planet Mars than we do of the moon," says Tooley, who notes that on current lunar maps, the locations of craters and mountains near the poles could be off by miles.
And the maps don't have detailed information about smaller landscape features, which would make it difficult to pick a safe spot for a future landing site in the unexplored regions.
Right now, moon mission planners wouldn't know if a potential landing site might actually be "a boulder field with, you know, house-sized boulders, or significantly sloped craters," Tooley says.
The lunar orbiter will circle about 31 miles above the lunar surface, gazing down at it with seven science instruments.
Its camera system should be able to detect anything that's bigger than about a foot-and-a-half across, and Tooley says it should even be able to spot some artifacts from the Apollo missions, like the rovers, or tire tracks.
Searching For Water Ice
If NASA does eventually send astronauts back to make brand new tracks, the lunar poles are appealing as a destination, because scientists think they might be home to water ice — something that could come in handy for explorers who might want to spend long periods on the moon.
"It's very, very interesting if water ice is indeed there," says Dan Andrews, of NASA's Ames Research Center, who is project manager for the second lunar probe, the Lunar CRater Observation and Sensing Satellite (LCROSS).
Scientists have previously detected a curious abundance of hydrogen in some dark, cold, permanently shadowed craters at the lunar poles. That could mean frozen water, Andrews says, but "that is no guarantee that there's water ice there, and so there's the open question."
Crashing Into A Crater
To try to answer that question, LCROSS will try to kick up evidence of water by basically throwing a big piece of trash into a dark crater to create an explosive impact.
The spacecraft will do this by taking the spent upper stage of its rocket and putting it onto a collision course with the lunar surface.
"We're not shooting it into the moon," Andrews says. "We simply let go of it, and the lunar gravity actually pulls it in."
The rocket part will smash into a crater at about 5,580 miles per hour and send up a huge plume of dust — and maybe ice — around 6 miles above the lunar surface. People on Earth who have a decent amateur telescope may be able to see it, if they're in the right spot.
Meanwhile, the LCROSS probe will get a more close-up view as it follows the path of its rocket part and flies down through the plume, taking measurements as it goes.
All of the science data will be sent back to Earth in real time, because just four minutes later, the spacecraft will slam into the crater and be destroyed as its partner on this moon mission, the Lunar Reconnaissance Orbiter, watches from above.
Together, the two moon missions carry a price tag of about $580 million.
Returning To The Moon
NASA's current goal is to return humans to the moon by 2020, and it is working on new rockets and capsules that could do so. Those space vehicles would replace the aging space shuttles, which are due to be retired next year, but the new vehicles would not be ready before around 2015.
President Obama's administration recently ordered up an independent review of the nation's entire manned spaceflight program. The panel of outside experts had its first public meeting Wednesday and is expected to report its findings by August.