Fergie's Tech Blog

Apollo 11 lunar landing anniversary

On July 20, 1969, while on the far side of the Moon, the lunar module, called Eagle, separated from the Command Module, named Columbia. Collins, now alone aboard Columbia, carefully inspected Eagle as it pirouetted before him. Soon after, Armstrong and Aldrin fired Eagle's engine and began their descent. They soon saw that they were "running long"; Eagle was 4 seconds further along its descent trajectory than planned, and would land miles west of the intended site. The LM navigation and guidance computer reported several "program alarms" as it guided the LM's descent. These alarms tore the crew's attention away from the scene outside as the descent proceeded. In NASA's Mission Control Center in Houston, Texas, a young controller named Steve Bales was able to tell the flight director that it was safe to continue the descent in spite of the alarms.

Once they were able to return their attention to the view outside, the astronauts saw that their computer was guiding them toward a landing site full of large rocks scattered around a large crater. Armstrong took manual control of the lunar module at that point, and guided it to a landing at 4:17 p.m. Eastern Daylight Time on July 20 with less than 30 seconds' worth of fuel left. Although it is commonly said that the first words spoken on the Moon were Armstrong's announcement that "Houston, Tranquility Base here. The Eagle has landed", they were in fact "Contact Light" said, by Aldrin as the landing probes on the Lunar Module's feet touched the surface.

posted by Fergie @ 7/20/2005 07:17:00 AM