| A lot more rocket failures are recoverable than you might think, though. Engines can fail in many ways that don't destroy everything. Apollo 13 nearly became famous for exploding on launch due to massive resonant vibration, but a premature shutdown of the affected engine saved it. (Oddly, that shutdown was due to a mistaken fuel level reading, not the vibrations directly, so the save was something of an accident.) At least one Shuttle launch experienced an engine failure/shutdown as well. These engines didn't explode, of course, but there's a whole range of failures and many can be planned for. Even when the entire thing does explode, you can still save your crew if you've planned properly. A Soyuz capsule's escape system saved its crew when the rocket exploded in 1983. It appears to me that NASA's approach is to prefer systems which can't fail over systems which can fail safely. On the surface, this seems better, but when your foolproof system still fails and you haven't built it to withstand that, then you're in serious trouble. I don't think there's any inherent reason why shedding a turbine blade during a rocket launch has to destroy the entire vehicle. Designing the system to withstand that makes it heavier and not perform as well, of course, but it seems like an overemphasis on performance while disregarding nearly everything else has really hurt space technology. |
There's a video of the Soyuz explosion mentioned above at http://www.youtube.com/watch?v=UyFF4cpMVag&noredirect=1 that shows the escape system saving the crew.
The use of solid rocket boosters for human space flight (as was planned for Ares I) is hugely controversial because they can't just be shut down in the event of a problem, as regular engines can, making survivability more difficult.
Personally, I think NASA is overly risk-adverse, to the point that nothing gets accomplished (see Constellation / Ares I). An interesting article on this is http://www.popularmechanics.com/science/space/news/4330356
On the topic of aircraft turbine failures, there's the interesting case of a DC-10 engine that disintegrated in flight due to a pilot experiment, killing a passenger. For details see: http://en.wikipedia.org/wiki/National_Airlines_Flight_27
Finally, if you're interested in SpaceX, NASA budgeting, and so forth, I recommend http://nasawatch.com