Space Forum / Shuttle / May 2004

A while ago on the discussion thread about the risks to an HST servicing
mission I cited a study listed in Paul Jenkin's book on the History of the
Space Shuttle that stated the odds of a launch failure or landing failure and
subsequently there was a debate over what a launch or landing failure was.

This is the exact text from page 281:

"Failure analysis conducted as early as 1979 on the Space Shuttle had concluded
that one in fifty flights would encounter a catastrophic accident during
ascent, and one in 100 would fail to land successfully. The failure analysis
have been updated repeatedly, and until recently, had always reached much the
same conclusion."

The appendix cites this study from the Rogers, Presidential Commission Report.

I was wrong about this statistic being still supported by NASA apparently as it
states this statistic remained the same until recently, however, it clearly
defines what this study considered a launch failure ("a catastrophic
accident"), which can only indicate an explosion or some other failure that
completely prevents the vehicle from completing the launch phase). The landing
statistic is not specific on what form of landing failure, but I personally
feel it intended to be failures in the re-entry and landing phase of the
flight. What could cause a failure to complete the landing is unspecified.

Anyway, I wanted to get the actual quote up because I felt like a crappy
historian for citing something and then failing to find the actual text for
weeks. I just happened upon it again while skimming through the book.

-A.L.