Re: RLV physicaly impossible ?

[EMAIL PROTECTED] (Paul Spielmann) wrote in message news:<[EMAIL PROTECTED]>...
 
> 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