I was involved in a similar discussion a couple of weeks ago. I was looking at the same figures you were and complimented the space shuttle because of it.
I was wrong, and you're making the mistake that I did. Namely confusing reliability and safety. A reliable rocket is one that successfully does what it is supposed to. A safe rocket is one that doesn't kill people.
The US space shuttle has proven to be more reliable than the Soyuz. It is more likely to actually get you into space. But the Soyuz has been safer than the US space shuttle. If you try to get into space on it, you're less likely to die.
If this seems impossible, consider that in both Soyuz 18a in 1975 and Soyuz T-10-1 in 1983 the rocket failed, but the cosmonauts survived. (In the first case the rocket failure happened 90 miles in the air, but the cosmonauts survived.) The space shuttle, by contrast, had no successful aborts.
So, this is why you top-load the crew compartment, and not side-load like the shuttle. There's no eject-system that could have saved a space shuttle in a situation like that since it would be engulfed by flames together with the rocket itself. This is also how SpaceX are doing it and for exactly this reason iirc.
Well, you are definitely right that people should go on the top of rockets, not near the middle.
The Challenger explosion could have hypothetically been survivable though. In fact, the explosion itself was survived, likely by all of the crew. The crew cabin (http://upload.wikimedia.org/wikipedia/en/thumb/4/42/Challeng...) remained intact and possibly pressurized after vehicle breakup. The crew were almost certainly alive (and if the cabin remained pressurized, could have been concious as well) for nearly 3 minutes until it hit the ocean at over 200 miles per hour.
At some point during those 3 minutes, I don't know if the SR-71 ejection seats used for the first few Shuttle launches could have improved their chances of survival, but it seems at least somewhat possible that it could have. A parachute system for the crew cabin probably wouldn't work for the same reason the launch abort system on the proposed Ares was flawed (flying burning solid fuel going everywhere in the air is bad for parachutes)... nevertheless I think it is conceivable that you could build a Shuttle that would allow the crew to survive an accident like that.
But really, just stick the people on top. It makes way more sense. I know it is hard to compare the two accidents (though from what I understand, as far as solid fuel rocket failures go Challenger was pretty tame), but the contrast between Challenger and T-10-1 is something that lessons should be taken from.
I think it is reasonable to say the shuttle was supposed to "get into space on the day it was planned to launch".
I do not have data on it, but using that yardstick or even the more lenient "get into space within a month of the planned date", I think it was not very reliable. I also have the impression (but again: I do not have data) that the Soyuz is way more reliable in that respect.
I was wrong, and you're making the mistake that I did. Namely confusing reliability and safety. A reliable rocket is one that successfully does what it is supposed to. A safe rocket is one that doesn't kill people.
The US space shuttle has proven to be more reliable than the Soyuz. It is more likely to actually get you into space. But the Soyuz has been safer than the US space shuttle. If you try to get into space on it, you're less likely to die.
If this seems impossible, consider that in both Soyuz 18a in 1975 and Soyuz T-10-1 in 1983 the rocket failed, but the cosmonauts survived. (In the first case the rocket failure happened 90 miles in the air, but the cosmonauts survived.) The space shuttle, by contrast, had no successful aborts.