It Found What the Moon's Made Of

摘要

MORE THAN 500,000 people watched as Apollo 17, the last crewed mission to the moon, blasted off from Kennedy Space Center on December 7,1972. When a U.S. probe returned to the moon 20 years later, hardly anyone noticed. The Clementine spacecraft, launched from Vandenberg Air Force Base on January 25,1994, started as a Department of Defense project. Its miniaturized sensors had been developed for President Ronald Reagan's Strategic Defense Initiative (known as "Star Wars") to detect and track missiles but, with NASA participation, also proved valuable to science.