Jeff Bell made many interesting comments. The comment about Bush's Space Initiative being "a roadmap for the quiet and orderly phase-out of manned space flight" has a ring of truth to it and causes me some concern. However Jeff Bell did say some things that were incorrect:

>But won't we be getting a much better spacecraft than Apollo? Haven't
>we made all kinds of technical advances since 1963? Can't we pick a
>new shape that will be kinder and gentler? Won't advanced composite
>materials and electronics make the CEV much lighter than Apollo?
>
>Well, no. The original Apollo team had the benefit of actual tests of
>hundreds of possible reentry shapes made by the US and UK missile
>programs in the mid-50s. They explored every possibility with wind-tunnel
>and arcjet tests, and all the promising shapes got actual flight tests at
>Wallops Island or Woomera.

It is true that much of the pioneering work in hypersonics was done in the
United States and United Kingdom in the late 1950s and early 1960s.
This work was done in support of ballistic missile development (space exploration was an after thought). Some of this work resulted in extremely clever closed form mathematical solutions modeling very complicated phenomena (digital computers back then had little more capability than modern day pocket calculators). The basic design of the Apollo Command Module (CM) was made very early in the Apollo program. The business end of the CM heat shield was based upon a spherical section. The engineers chose the spherical section because they were risk adverse and wanted to follow a KISS philosophy (Keep It Simple Stupid). The aerodynamics of a spherical section is "dumb as dirt". Static stability for all Mach numbers is assurred if the center-of-mass is up stream from the center-of-curvature. However the lift-over-drag ratio for a spherical section is awful. During its return from the Moon, the CM had to fly within a very narrow entry corridor. The CM was trimmed at a fixed angle of attack. The trajectory was controlled purely by roll modulation. If you look at a plot of roll angle as a function of time for an early unmanned Apollo CM test flight, you'll see something that looks like white noise. The guidance computer was going nuts, trying to keep the CM within its entry corridor. The situation was more controlled after the early test program but it was still a wild ride. A "rake conic", biconic or some sort of lifting body have much better lift-over-drag ratios and are more suited for high speed entry into the Earth's atmosphere. If all you want to do is reenter from Low Earth Orbit following a sloppy, low energy entry vector, then a spherical section like the CM is a cheap and acceptable approach, e.g. an escape pod for the ISS. However if you're screaming in at 13 km/sec on a return trajectory from Mars then you should be flying in a modern vehicle geometry that was validated with current flight test data and computational fluid dynamcs. With current technology, we can do better than the old CM.

Gary