Jul 20, 200602:52 PMThe Life

Wide Awake on the Sea of Tranquillity

On July 20, 1969 (37 years ago today), humans landed on the moon. Here's an excerpt from the fourth installment of Science@NASA's Apollo Chronicles:

[...] when Armstrong saw where the computer was guiding them--into a boulder field-­-he quickly took control. The Eagle pitched forward and sailed over the rocks.

Meanwhile, alarms were ringing in the background.

"Program alarm," announced Armstrong. "It's a 1202." The code was so obscure, almost no one knew what it meant. Should they abort? Should they land? "What is it?" he insisted.

Scrambling back in Houston, a young engineer named Steve Bales produced the answer: The radar guidance system was pestering the computer with too many interruptions. No problem. "We've got you..." radioed Houston. "We're Go on that alarm."

And on they went. Things, however, were not going exactly as planned. The Sea of Tranquillity was supposed to be smooth, but it didn't look so smooth from the cockpit of the Eagle. Armstrong scanned the jumbled mare for a safe place to land. "60 seconds," radioed Houston. "30 seconds." Mission control was hushed as the telemetry came in. Soon, too soon, the ship would run out of fuel.

Capcom later claimed the "boys in mission control were turning blue" when Armstrong announced "I [found] a good spot." As for Armstrong, his heart was thumping 156 beats per minute according to bio-sensors. The fuel gauge read only 5.6% when the Eagle finally settled onto the floor of the Sea of Tranquillity.

Houston (relieved): "We copy you down, Eagle."

Armstrong (coolly): "Houston, Tranquility Base here. The Eagle has landed."

Immediately, they prepared to leave. This was NASA being cautious. No one had ever landed on the Moon before. What if a footpad started sinking into the moondust, or the Eagle sprung a leak? [...]

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