At 7:30 EST on Friday, the National Aeronautics and Space Administration deliberately crashed two orbiting probes into Cabeus, a large crater near the south pole of the moon. This program, the Lunar Crater Observation and Sensing Satellite (LCROSS) mission, was designed to determine if the lunar surface contains water.

As the first part of LCROSS hurtled into the Moon's surface, it sent up a plume of rock and dust, which the second probe photographed. Shortly afterward, the other half of LCROSS also crashed into the Moon, creating another explosion that earthbound scientists could analyze.
LCROSS follows in the flightpath of India's Chandrayaan-1, an unmanned probe that entered lunar orbit last November and operated until August. Chandrayaan-1 uncovered evidence of water on the moon; if LCROSS can confirm those findings, it will ease the way for future moon exploration and colonization, as astronauts could use lunar water and help generate fuel for future spaceships.

Beyond that, though, LCROSS has already demonstrated the changing face of space exploration. Since the first satellites went up in the 1950's, decisionmakers have fought over the benefits of manned versus unmanned space exploration. Manned space travel, the path America followed in the 1960s and 1970s, is rich with romance, and astronauts have always been readymade heroes. Largely culled from the ranks of the armed forces, America's space warriors surveyed strange new vistas and went into metaphorical combat with the representatives of our Cold War enemies. In the process, they also put a powerful human face on what might otherwise be a less-than-exciting scientific endeavor.

On the other hand, manned space flight is incredibly expensive. In addition to the comparatively cheap process of sending a large chunk of metal into space, manned missions also have to find a way to send food, water, air, and living quarters. They have to train astronauts, create space foods, space toilets, spacesuits, and lunar rovers. Perhaps hardest of all, they have to figure out a way to bring space travelers and their accessories back home intact.

The LCROSS program provides an outstanding demonstration of the costs involved in manned spaceflight. While the satellite's $79 million price tag is nothing to sneeze at, it pales next to the estimated $28 billion to $36 billion that the next manned mission to the moon is expected to cost. In fact, for the cost of a single manned landing, NASA could send more than 450 LCROSS probes to the lunar surface.

The trouble is, as the Mariner 9, Spirit, and Opportunity programs show, the public doesn't really care all that much about unmanned missions. The U.S. has sent probes to all of our nearby planets, and has even shot the Voyager craft beyond the solar system. Despite some dynamite pictures and a great deal of useful scientific information, the public response has been less than stellar.

With LCROSS, NASA attempted to fight the general disinterest over unmanned probes, suggesting that the mission -- and the 6.2-mile-high plume of lunar dust that it was expected to generate -- would be nothing less than spectacular. For most viewers, however, the lunar penetration was a serious letdown.

The lesson is clear: when it comes to space exploration, it seems that you get what you pay for. While astronauts whacking golf balls on the lunar surface might not yield impressive scientific data, they capture the imagination of viewers and offers the kind of exciting vision that inspires future space funding.