That having been said, it's still not safe enough. For example, what about a birdstrike or other debris? A small capsule on top of the stack would have a protective shroud while it is in the atmosphere, and the heatshield is at the bottom anyway. The Shuttle/Buran design was too big to protect in this way.
From my understanding a Bird Strike during launch would only occur very early in the flight, where the shuttle was still traveling at a relatively low speed.
> From my understanding a Bird Strike during launch would only occur very early in the flight, where the shuttle was still traveling at a relatively low speed.
There are a number of birds that can fly up to 10,000 feet. At 10,000 feet, the Shuttle is doing half the speed of sound. Hitting a bird at 10,000 feet would've been no picnic.
(In fact, the altitude record for birds is above 30,000 feet -- but these are unlikely to be found in Florida.)
Soyuz and Shenzhou both have a payload fairing that covers the entire spacecraft. Apollo had a partial shroud that covered the command module. These spacecraft do not even have an exposed heatshield during launch. Apollo didn't even need a fairing for aerodynamic reasons -- but it still had one anyway.
However, it was not vulnerable to falling foam, because the Soviets put the insulation on the inside of the Energia: http://www.newscientist.com/article/dn20664-cosmonaut-soviet...
That having been said, it's still not safe enough. For example, what about a birdstrike or other debris? A small capsule on top of the stack would have a protective shroud while it is in the atmosphere, and the heatshield is at the bottom anyway. The Shuttle/Buran design was too big to protect in this way.