Shooting for the Moon.

Abstract

![][1] The first Apollo 11 lunar sample to be analyzed in a laboratory, photographed on 27 July 1969 in a vacuum chamber at NASA's Lunar Receiving Laboratory. PHOTO: NASA/NOVAPIX Fifty years ago, on 20 July 1969, the first humans landed on the surface of another world, when the Apollo 11 lunar module touched down on the Moon. A few hours later, astronauts Neil Armstrong and Buzz Aldrin took the first steps onto an alien surface while Michael Collins orbited overhead in the command module. The motivation for this milestone of space exploration was geopolitical, not scientific. The Apollo program was intended to demonstrate technological supremacy during the Cold War space race. Yet Apollo 11 and the five additional crewed landings that followed have left a rich scientific legacy. They carried a variety of instruments, including seismometers, magnetometers, and retroreflectors for laser ranging observations. Perhaps their greatest scientific value lies in the 382 kg of rocks and regolith (lunar soil) that were brought back to Earth. Laboratory analysis of these samples revolutionized our understanding of how the Moon, Earth, and other planets formed. Improved technology and advances in planetary science mean that the samples are still actively studied today. Funding for lunar exploration soon ran out. No humans have traveled beyond low Earth orbit since Apollo 17 in 1972, and even robotic missions to the Moon ceased between 1976 and 1990. The 21st century has seen a renewed interest in exploring our nearest neighbor, in part because a growing number of space agencies and private companies now have the capability to reach it. Some have plans to return humans to the lunar surface over the next decade. Even more ambitious are ideas for permanent lunar bases, such as astronomical observatories, which could reap a rich scientific harvest. One day humans will return to the Moon. Until then, the Apollo landings stand alone at the pinnacle of crewed space exploration. [1]: /embed/graphic-1.gif