Sunday, January 28, 2007

An Error Message During Eagle's Descent

Not Just Delighted, They Were Over The Moon

Ever heard of a bloke called Steve Bales? No? Well, neither had I, until today. Bales played a critical role in making a snap decision during the Apollo XI lunar landing.
According to a report at abc.net.au, he was the one who had to make a critical call as Neil Armstrong and Buzz Aldrin were halfway through the descent to the moon's surface. A yellow warning lamp lit up on the computer control panel as Eagle, the Lunar Module, was about 2000 metres above the moon's surface. ``It was a 1202 error, indicating a memory overload,'' says the report, ``and the astronauts asked Mission Control for instructions.''
The responsibility now shifted to Bales, the expert in the lunar module's guidance systems. This was the most critical call in the entire Apollo space programme. Was the United States about to postpone its long-held ambition to put man on the moon?
Was the computer error serious enough to abort the lunar landing?
A colleague named Jack Garman, working at another console, recalled that a similar problem had occurred during a computer simulation a week earlier.
Confidently, he reassured Bales that the descent could continue. The report quotes Bales saying: ``I had just started to relax a little bit, if you can call it relaxing, and I heard the program alarm. Quite frankly, Jack, who had these things memorised said, 'that's okay', before I could even remember which group it was in. I remembered yeah, that's one of those we said it's okay. I looked up, the rest of the computer looked good, so I said 'Lets go!' It took us a long time. In the Control Centre any more than three seconds on descent is too long .... and it took us about ten to fifteen seconds."
Sure enough, the software rebooted and reinitialised the computer. It was a good decision, made under unbelievable pressure. The report states: ``The same error repeated itself several times in the following minutes, but did not stop the Eagle from landing.''
Want to know how the story ended? Neil Amrstrong, Buzz Aldrin and Michael Collins all received the US Medal of Freedom. But a fourth Medal of Freedom was also awarded to a civilian. He was only 26 years old. His name was Steve Bales.

It'd be great if any of my US readers could add to this. Are any of Steve Bales' relatives out there? I'd love to hear from you.

No comments: