The Lunar Crater Observation and Sensing Satellite (LCROSS) was a robotic spacecraft operated by NASA. The mission was conceived as a low-cost means of determining the nature of hydrogen detected at the polar regions of the moon. The main LCROSS mission objective was to explore the presence of water ice in a permanently shadowed crater near a lunar polar region. It was successful in discovering water in the southern lunar crater Cabeus. LCROSS suffered a malfunction on August 22, depleting half of its fuel and leaving very little fuel margin in the spacecraft.