Back in August of 2010—a year and a half ago—The Air Force launched the first of four AEHF satellites (Advanced Extremely High Frequency). The launch was perfect. Then, a couple of days later, the Launch Control folks tried to fire the hydrazine fueled "liquid apogee engine" (LAE), and it didn't. And it didn't a few days later, on a second attempt. That is when the launch team got down to serious analysis.♠ They determined a third attempt to fire the LAE might result in catastrophic failure. Equally important, they figured out how to use maneuvering thrusters to slowing ease the big satellite up to its 22,300 mile geosynchronous orbit over the Galapagos Islands. That is, half pound thrust thrusters to move a satellite with a mass of 13,600 pounds.
This is a great story about letting the operators handle the problem. It is also, I would think, a great story about how "over design" pays off when the known and unknown unknowns become a problem. Yes, it is so-called "gold plating" and there are times when that is much appreciated by the operators.
I noticed that this story was also published by The Register.
In the interest of full disclosure, my middle brother was the Deputy Program Manager for this program, for Lockheed, the Prime on this project, but he retired before launch. He was unavailable for comment.
Regards — Cliff
♠ The author of the Air Force Magazine article was Mr Robert S. Dudney.
No comments:
Post a Comment