(Paul Spielmann) wrote in message . com...

I suppose you mean an approach that is simple is prefered, to make
rlvs possible ? anyway i tend to like "simple" and "clean"
approaches... like thouse of scaled composites and armadillo
earospace. It seems the space shuttle as you meantioned is really
"complex"

The shuttle also had to do a lot of things that the Scaled Composites
and Armadillo Aerospace X-Prize vehicles did not.

For example, the shuttle had to reach orbital velocities and return
from them. No X-Prize vehicle that I know of is approaching 1/4 of
orbital velocity (17500mph); I think the Scaled Composites vehicle is
topping out at ~2500mph.

The shuttle had to meet a lot of military needs, like a 1500-mile
cross-range so it could land at its launch site after a single polar
orbit. Before the USAF joined the shuttle project, some shuttle
designs featured small, stub wings optimized for low-speed
performance. On designs like Faget's "stub wing orbiter," the shuttle
would aerobrake with its belly (~60-degree angle of attack) with
leading edges...well, they weren't really leading edges. But Faget was
designing for a civilian vehicle that could accept 200-300 miles of
cross-range and wait in orbit until it was again lined up with its
landing site. Metallic heat shields were also considered before the
USAF jumped/was shoved aboard. After the USAF signed up, only ceramic
heat shields would get the job done.

A lot was asked of the shuttle, more than most current RLV designs are
expected to do.

Mike Miller, Materials Engineer