For a different and interesting view of how NASA worked during the Apollo era, read a book titled Failure Is Not An Option by Gene Kranz. Gene Kranz was a NASA Flight Director for many years. (You may remember him from the Ron Howard movie "Apollo 13" as the one in the fancy sweater.) -- Rich Wynn Rostek wrote: > > > The shuttle engines are ammonium perchlorate, aluminum, and a binder, > which > > is what the Aerotech reloads are made from. Not black powder. The failure > > was due to a rubber O-Ring that lost it's flexibility in the low > temperatures. > > > > The solid rocket boosters are ammonium perchlorate, aluminum and binder. The > failure was due to a combination of poor judgement on managment's parts, and > bad luck. > The O-Ring was not rated for use at that low of a temperature. There was ice > on the shuttle that day. Several people advised against a launch attempt. > Management decided to go anyway. This happens all the time, for a variety of > reasons. It is still going on today. There were at least 4 counts that I > know of in the last 12 months that were recommended against. (Usually for > low probability of acceptable weather.) One was a successful launch. That's > what they pay the guys for, to make the go/no-go call on the launch > attempts. They almost always try, and they frequently get away with it. One > time they didn't. Actually they fail to get away with it all the time, its > just that it usually doesn't result in quite so press coverage. > > James Womack Sr's first launch as director of expendable vehicles was a real > disaster. He is the father of a hunting buddy of mine, and he had been > working on the manned side for many years. On the expendable side the rules > a lot different because the payload is owned by a company interested in > getting it in orbit and on line to get the revenue stream going. They have a > whole lot more say in when an attempt is made and when you scrub. This > results in different language being used when you get weather advisories. > The time of launch approached, James asked for a call on the weather, which > was dicy at best, and the weather advisor told him that it was go if James > desired, meaning if the customer wanted to risk it, it was his payload. > James was used to manned weather reports. They launched, the bird blew up > and a grand time was had by all. > > Back to the bad luck bit. Few people know it, but the SRB nozzles were > slewwed over, trying to compensate for the side thrust from the leak at the > field joint. (The SRB's are actually sections because you can't cast that > much propellant in one go. The sections are then pinned together and a metal > band hold the pins in place. The result is called a field joint.) They kept > the shuttle on track, leak and all. If that leak had developed on a slightly > different section of the O-Ring, the flame would have jetted out into space, > never would have burned through the external tank, and only a few of us > space workers would have ever known about it. 30 degrees of danger and we > ended up unlucky. > > Wynn Rostek > > Former Shuttle Worker > CBEP (SRB Power Distribution and Control) > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.