[meteorite-list] Crash Landing on the Moon (LCROSS)
From: E.P. Grondine <epgrondine_at_meteoritecentral.com>
Date: Fri Jul 28 23:24:21 2006 Message-ID: <20060729032416.98037.qmail_at_web36901.mail.mud.yahoo.com> Hi all - Not a bad idea; kind of looks like Chang'e 1: http://www.friends-partners.org/pipermail/fpspace/2006-May/019800.html I hope the Chinese outline their lunar observatory plans at the ILEWG meeting in Beijing July 27-29. I hope they'll broadly describe some type of CAPS variant. good hunting - Ed --- Ron Baalke <baalke_at_zagami.jpl.nasa.gov> wrote: http://science.nasa.gov/headlines/y2006/28jul_crashlanding.htm > > Crash Landing on the Moon > NASA Science News > July 28, 2006 > > July 28, 2006: In 1959, a spaceship fell out of the > lunar sky and hit > the ground near the Sea of Serenity. The ship itself > was shattered, but > its mission was a success. Luna 2 from the Soviet > Union had became the > first manmade object to "land" on the Moon. > > This may seem hard to believe, but Luna 2 started a > trend: > Crash landing on the Moon, on purpose. Dozens of > spaceships have done it. > > NASA's first kamikazes were the Rangers, built and > launched in the early > 1960s. Five times, these car-sized spaceships > plunged into the Moon, > cameras clicking all the way down. They captured the > first detailed > images of lunar craters, then rocks and soil, then > oblivion. Data beamed > back to Earth about the Moon's surface were crucial > to the success of > later Apollo missions. > > Even after NASA mastered soft landings, however, the > crashing continued. > In the late 1960s and early 70s, mission controllers > routinely guided > massive Saturn rocket boosters into the Moon to make > the ground shake > for Apollo seismometers. Crashing was much easier > than orbiting, they > discovered. The Moon's uneven gravity field tugs on > satellites in > strange ways, and without frequent course > corrections, orbiters tend to > veer into the ground. Thus the Moon became a > convenient graveyard for > old spaceships: All five of NASA's Lunar Orbiters > (1966-1972), four > Soviet Luna probes (1959-1965), two Apollo > sub-satellites (1970-1971), > Japan's Hiten spacecraft (1993) and NASA's Lunar > Prospector (1999) ended > up in craters of their own making. > > Back to the Future > > All this experience is about to come in handy. NASA > researchers have a > daring plan to find water on the Moon and they're > going to do it by--you > guessed it--crash landing. The mission's name is > LCROSS, short for Lunar > CRater Observation and Sensing Satellite. Team > leader Tony Colaprete of > NASA Ames explains how it's going to work: > > "We think there's frozen water hiding inside some of > the Moon's > permanently-shadowed craters. So we're going to hit > one of those > craters, kick up some debris, and analyze the impact > plumes for signs of > water." > > The experiment couldn't be more important. NASA is > returning to the > Moon, and when explorers get there, they'll need > water. Water can be > split into hydrogen for rocket fuel and oxygen for > breathing. It can be > mixed with moondust to make concrete, a building > material. Water makes > an excellent radiation shield, and when you get > thirsty you can drink > it. One option is to ship water directly from Earth, > but that's > expensive. A better idea would be to mine water > directly from the lunar > soil. > > But is it there? That's what LCROSS aims to find > out. > > The quest begins in late 2008 when LCROSS leaves > Earth tucked inside the > same rocket as Lunar Reconnaissance Orbiter (LRO), a > larger spacecraft > on a scouting mission of its own. After launch, the > two ships will split > up and head for the Moon, LRO to orbit, LCROSS to > crash. > > Actually, says Colaprete, "we're going to crash > twice." LCROSS is a > double spacecraft: a small, smart mothership and a > big, not-so-smart > rocket booster. The mothership is called the > "Shepherding Spacecraft" > because it shepherds the booster to the Moon. > They'll travel to the Moon > together, but hit separately. > > The booster strikes first, a savage blow > transforming 2-tons of mass and > 10 billion joules of kinetic energy into a blinding > flash of heat and > light. Researchers expect the impact to gouge a > crater ~20 meters wide > and throw up a plume of debris as high as 40 km. > > Close behind, the Shepherding Spacecraft will > photograph the impact and > then fly right through the debris plume. Onboard > spectrometers can > analyze the sunlit plume for signs of water (H2O), > water fragments (OH), > salts, clays, hydrated minerals and assorted organic > molecules. "If > there's water there, or anything else interesting, > we'll find it," says > Colaprete. > > The Shepherd then begins its own death plunge. Like > the old Rangers, it > will dive toward the lunar surface, cameras > clicking. Back on Earth, > mission controllers will see the booster's glowing > crater swell to fill > the field of view--an exhilarating rush. > > Until the very end, the Shepherd's spectrometers > will keep sniffing for > water. "We'll be able to monitor the data stream > down to 10 seconds > before impact," says Colaprete. "And we should have > enough control to > land within 100 meters of the booster's crash site." > > The Shepherd is 1/3rd lighter than the booster, so > its > impact will be proportionally smaller. Nevertheless, > the Shepherd will > make its own crater and plume, adding to those of > the booster. > Astronomers hope the combined plumes will be visible > from Earth, > allowing observations to continue even after the > Shepherd is destroyed. > > Many readers will remember the crash of Lunar > Prospector in 1999. > Mission controllers guided the ship into Shoemaker > crater near the > Moon's south pole in hopes of kicking up water - > just like LCROSS. But no > water was found. > > "LCROSS has a better chance of success," says > Colaprete. For one thing, > LCROSS delivers more than 200 times the impact > energy of Lunar > Prospector, excavating a deeper crater and throwing > debris higher where > it can be plainly seen. While Lunar Prospector's > plume was observed only > by telescopes on Earth a quarter-million miles away, > LCROSS's plume will > be analyzed by the Shepherding Spacecraft at point > blank range, using > instruments specifically designed for the purpose. > > Only one question remains: Where will LCROSS strike? > > "We haven't decided," he says. The best places are > probably polar > craters with shadowy bottoms where water deposited > by comets long ago > may have frozen and survived to the present-day. > Less orthodox choices > include canyons, rilles and lava tubes. "There are > many candidates. > We're convening a meeting of researchers to debate > the merits of various > sites and, finally, to pick one." > > ______________________________________________ > Meteorite-list mailing list > Meteorite-list_at_meteoritecentral.com > http://six.pairlist.net/mailman/listinfo/meteorite-list > __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com Received on Fri 28 Jul 2006 11:24:16 PM PDT |
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