“The Apollo programme of the 1960s had some weight problems, too; in pa...” — Henry Spencer Quote

The Apollo programme of the 1960s had some weight problems, too; in particular, the lunar lander needed some fairly drastic weight-reduction work.

Past experience, on the shuttle and the Titan rockets, suggests that large multi-segment solid rockets have a probability of failure of 0.5 to 1 per cent.

In the long run, it's impossible to make progress without sometimes having setbacks, although people who get lucky on their first attempt sometimes forget this.

The Orion capsule uses an escape system quite like that of the Apollo spacecraft in the 1960s and 70s: an 'escape tower' containing a solid-fuel rocket that will pull it up and away from Ares I in a pinch.

A typical smart phone has more computing power than Apollo 11 when it landed a man on the moon.

During one of the Apollo missions, I saw Walter Cronkite showing off the flight plan. It just mesmerized me. All this detail! That's what I wanted.

I was born too late to experience Apollo 11, though I do trek to Dad's house every time there's some space event. There's something awesome about crossing your fingers and watching a tense Mission Control room do their thing.

I wouldn't trade my career with anybody's. I'd trade a few movies with Tom Hanks - 'Apollo 13' and 'Forrest Gump' - but other than that, I love my career.