Headline Sep5,2012/"Fast Time!"

"FAST TIME!"

Perhaps the toughest thing about landing on the Moon was that there was no such thing as a second chance. Separated from Columbia, the Eagle began its descent towards the Moon by using a special grid called the Landing Point Designator which told the Astronaut where the computer was aiming to land. LPD grid was marked off in degrees on the Lunar Module's double pane window. If Armstrong didn't like what he saw, he could tell the computer to change its aim by nudging the LM's attitude controller. In theory, Armstrong knew, he could let the computer fly the LM all the way to the touchdown.

Flying the LM entirely by hand was so difficult that Armstrong wanted to avoid it all costs, and unless the computer went out, he wouldn't have to. Armstrong knew that there was always the possibility that something would go wrong , from communication failure to a malfunction of the descent rocket, and force him to abort the landing. In that case he could press the button marked ABORT STAGE, setting off a dramatic chain of events. In an instant, pyrotechnics bolts would server the connections between the descent and ascent stages. At the same moment the ascent rocket would blast to life, boosting Armstrong and Aldrin back toward orbit. But an abort, especially one at low altitude, carried its own risk. If the ascent engine didn't light, there would be no time to find out why and do something about it; Armstrong and Aldrin would crash in matter of seconds. Even if it did fire, the ascent stage might not separate cleanly from the descent stage. And if there were no malfunctions, there was the problem of finding Collins, with the timing for the rendezvous now completely disrupted.

Armstrong and Aldrin would face a long and complicated journey back to the command module. And it would have been several hours since Aldrin had aligned the LM's guidance system with the stars. An abort would force the men to fly with  guidance system with the stars. An abort would force the men to fly with a guidance system that could be significantly in error. And so the last thing Armstrong wanted to do was abort, not only because it would mean failure, but because it could be even more risky than the landing itself. As the LM got very close to the moon, Armstrong and Aldrin would enter the most hazardous portion of the descent. Somewhere in the last 200 feet, they would be too low to abort successfully, if the descent engine quit, for the LM would be going too fast for the ascent engine to arrest the Lander's plunge and start the ascent stage upward again.

The Astronauts, borrowing a term from Helicopter Pilot's, called this part of the descent the "dead man's curve". Even if nothing went wrong, Armstrong would have his hands full. Already, he would have had to find a safe landing sport, free of large craters and boulders. By the time LM was 100 feet up, Armstrong would have to arrest nearly all forward motion and begin a slow, vertical descent. Truly remarkable complexity!

Good night and God bless!

SAM Daily Times - the Voice of the Voiceless