[r9etb]

I guess the genrally accepted needs are: 50,000 lb payload and reusablity and horizontal landing.

For the first, I think if you measured certain military satellites, you'll find that they just fit into the cargo bay. This is not an accident.

Military launches are now on expendables -- the Shuttle was too expensive, time-intensive, and too susceptible to significant delays due to mission failures, so that requirement no longer exists.

The ISS could be used for spacehab-type missions.

Cargo launches could be done Russian-style, as could the ferrying of astronauts: both use expendables. (I think, however, that we would want to land a bit more gracefully than the Russians do....)

The current Shuttle missions can for the most part be covered by expendable systems.

So the question is: is there really a requirement for reusables? I think there probably is -- the Shuttle is an incredibly flexible spacecraft. It's used for rendezvous, space and earth observation, satellite repairs, and a variety of other things, including ferrying crews and materials to and from ISS.

But I think those missions can likely be done on a much smaller platform.

[fooman]

Our program was going to use the SLD, but your right, we used something else instead that was expendable.

I know there was a drive to make birds smaller like our clementine mission, but not all birds can be made small.


I also think that horizontal take off and landing on some kind of ramjet platform would be cool, if it could made to work technically and economically