July 20, 2004
Lunar dreams
Thirty-five years ago today Neil Armstrong and Buzz Aldrin landed on the Moon, in a descent that was, unknown to us watching at home, barely controlled.
Emergency signals flashed within Eagle and one and a half seconds later on the consoles in Mission Control. No one expected a cry of danger. Not now.At 6,000 feet above the moon a yellow light flashed at the two moon landers. Buzz's voice responded immediately as he called out numbers flashing on his flight panel and on the console before Steve Bales in the control center.
Bales was the guidance officer, and none of the controllers called him by his name. He was called by his acronym, “GUIDO.”
"Program alarm," Buzz snapped crisply. "It's a twelve-oh-two."
Twelve-oh-two. A warning that the ship's main computer was overloaded. So much was happening, so many performance signals were being generated that the computer could not absorb them all. It was a cry for help.
There was no panic. Everyone sensed an abort. A hellish maneuver that would explosively separate the upper ascent stage of the Eagle from the landing stage and squeeze every ounce of thrust from the ascent rocket to make it climb back to a rendezvous and docking with the command ship Columbia. All eyes were on Bales.
He stared at his console. Coded numbers told him instantly what was going wrong. The computer within Eagle was being overtaxed with data. The alarm was the result of executive overload.
Armstrong's voice was strong. "Give us the reading on that twelve-oh-two program alarm," he demanded.
"GUIDO?" Flight Director Gene Kranz shouted. Everyone hung on the edge of their seats.
Bales wanted more time.
Kranz didn't have time. Armstrong and Aldrin didn't have a single second to spare as they plunged toward the moon. Kranz stared at Bales. The flight director slammed a fist against his console.
Bales jerked in his seat. No time. No damn time.
"GO!" he shouted. He closed his mike, staring at his console. "Go, damn it," he said in a hoarse whisper only to himself.
Duke showed surprise. He didn't have time to wait, either. His words came forth immediately. "We've got, uh, we're GO on that alarm, Eagle."
Thirteen hundred feet above the moon's surface, Eagle began its final descent. Flames gushed downward as the craft slowed, and Armstrong gripped the hand controller in his fist, firm and strong, with a touch honed by years of flight in jets and rockets.
Armstrong needed to hand-fly the rest of the way.
Now it seems like it was only a dream. When will we go back?
NASA has a cool commemorative Flash site.
NPR remembers Apollo 11's "close call" and has other archival content.