Hugh Pickens writes "NASA is preparing to launch the Lunar Crater Observation and Sensing Satellite (LCROSS) which will fly a Centaur rocket booster into the moon, triggering a six-mile-high explosion that scientists hope will confirm whether water is frozen in the perpetual darkness of craters near the moon's south pole. If the spacecraft launches on schedule at 12:51 p.m. Wednesday, it will hit the moon in the early morning hours of October 8 after an 86-day Lunar Gravity-Assist, Lunar Return Orbit (LGALRO) that will allow the spacecraft time to complete its two-month commissioning phase and conduct nearly a month of science data collection of polar crater measurements before colliding with the moon just 10 minutes behind the Centaur. The cloud from the Centaur rocket booster will kick up 350 metric tons of debris that should spread six miles above the surface of the moon, hitting the sunlight and making it visible to amateur astronomers across North America. Over the final four minutes of its existence, as LCROSS follows the same terminal trajectory as the Centaur, the spacecraft will train its instruments and cameras on the debris cloud, searching it for the chemical signature of water. Previous spacecraft and ground-based instruments have detected signs of hydrogen near the moon's poles, and scientists are split over whether that is from ice that could have arrived through the impact of comets or by other means. Despite all the serious scientific talk about hydrogen signatures and lunar regolith, flying a rocket booster into the moon at 5,600 mph to trigger a massive explosion is just flat-out cool. "We're certainly going to be making a big splash," says Kimberly Ennico, the LCROSS payload scientist. "We're going to see something, but I don't know what to expect. I know on the night of the impact, I'll be running on adrenaline.""