The agency's safety director and chief engineer wanted to wait and fix the problem. But NASA Administrator Michael Griffin decided a July 1 launch is worth the added risk for several reasons.
``It's a difficult decision, highly technical, highly subtle, very subtle, involves lots of assessment of statistical risks," Griffin said in an interview. with The Associated Press. ``We spent weeks on this decision."
In engineering geek-speak, what they did is called ``risk analysis." In everyday life, it's making up your mind about seemingly ordinary things that could be deadly.
Humans have gone into space 717 times and 18 astronauts and cosmonauts have died doing it: the seven Challenger astronauts, the seven aboard Columbia, and four cosmonauts in two Soviet accidents. (The total does not include the three astronauts who died in a fire during a launch pad test aboard Apollo 1 in 1967.)
Discovery astronaut Mike Fossum described how his family is dealing with the risk: ``I have to look my wife in the eye. . . . We've had those discussions. It's not one she is really comfortable with. It's not one anybody really is."
Fossum's crewmate Stephanie Wilson, who will be flying for the first time, joked that 1-in-100 odds are better than 1-in-99, but added, ``Seriously, all of us train for our mission, and we recognize there is a risk."
Michael Stamatelatos, who as director of safety and assurance requirements at NASA is the agency's risk guru, said that NASA's 1-in-100 odds for the loss of a vehicle and its crew should be taken with a grain of salt, because NASA used to say the chances were 1 in 7,000 until Challenger proved that to be overly optimistic.
He said there are too many uncertainties to say precisely what the odds might be this time.
