That was a tough day for many. Someone interrupted our meeting at a federal building, stunning us with the announcement, and I went to a coffee shop down the block to watch the video loops of the launch. My first thought was there was probably asbestos in the original seal design and some environmental requirement required it not be used in replacement seals. Not true. In the end, it has been my opinion, based on my casual overview of the congressional investigations, it turned out to be another “It is easier to blame a thing (cold temperature) than to blame people (faulty design).” Earlier analysis that said the joint should close during pressurization, when in reality the joint opened. That mistake was known by NASA management and should have been corrected long before any Shuttle was ever flown after that discovery. Engineers who flagged the problem could not prove that the O-rings would fail to seal at lower temperatures. Optimal launch temperatures were considered to be between 40 and 90 degrees. Challenger launched that morning in 22 degree weather.
Parker Hannifin is one of the world’s leading authorities on O-Ring design. In the Parker O-Ring Handbook ORD 5700 paragraph 4.0 says “It has been said that O-rings are ‘the finest static seals ever developed.’ Perhaps the prime reason for this is because they are almost human proof …. If the gland has been designed and machined properly”.
In 1987 when working in Germany, I attended a gathering in Lohr, where the Rexroth engineering firm, now part of Bosch, is located. Met two chaps from Rexroth and asked them how work was going on the redesigned Shuttle seals. They looked at each other and went mute. I guess it was supposed to be a secret. Anyway, the Hercules, Inc. "Capture Feature" of the “redesigned” seals finally gave us the ‘reusable’ solid rocket motor NASA wanted it to be--one that has been in use ever since.
In the end, our astronauts got a better SRB and the improved system has worked fine and lasted a long time. When I was a kid, I remember going out in the field to watch Sputnik blinking across our American sky. It was discomforting. The insult of it. Well, it created a new era and I and all my friends dreamed of space travel. Watching Neil Armstrong step out of the Apollo 11 lunar module brought cheers. Now, space launches are taken for granted, we don't have the names of Shuttle flight crews memorized before the launch. Our country still has technical expertise and the people who can figure out stuff. Everything is safer as a result of responding to the Challenger disaster. We are not going to forget it anything soon. Bless their memory.
