Introducing Ares, The next Generation in Spaceships, page 2

Hey guys, I just joined the forum and had to comment on this discussion.

First, single stage to orbit is not physically possible, your mass is just too much. SpaceShipOne was actually two stage to space (White Knight is considered a stage). Two stages is the minimum to orbit given normal calculations. Any rocketry book will tell you that pretty quickly. I believe the shuttle is two stage to orbit, solid rocket boosters then the shuttle engines. Newer designs with the plane flying the orbiter up will only work so well. You'd want something to get really high requiring a huge wing area compared to the relative weight, but most all jet engines will choke out before that happens. You can go for a local supersonic to run a ramjet (M0.9 and on the top of the wing in a lambda shock) to accelerate it faster. The orbiter would need to be in a sort of bay stored somewhere. It would then need to launch/ignite and take off into space.

As for getting into orbit, LEO (low earth orbit, where the shuttles play) velocity is about 8 kps (kilometers per second). LEO extends from 200 km to 1200 km altitude above the earth surface. Escape velocity from the surface is about 11.X kps, it drops as you get farther out, whatever. I can give you guys the equations if you want, they're pretty simple. Rockets are the ONLY solution for now and the near future. We've made a lot of progress from the alcohol and simple oxygen compounds for rocket fuel. We're now using liquid hydrogen and LOx for all stages and running the Carbon-Carbon nozzles well above their melting points, but they're surviving (we run the liquid propellants through the nozzles to cool them off).

As for alternate propulsion systems, the problem is that many of the newer ideas throw radioactive pollution into the air, or the fear of it doing it. Nuclear propulsion, the ideas for crew manned vehicles with this, had the reactor highly separated from the crew by a support structure. Not really good spacecraft design, probably not robust to damage. Nuclear propulsion also suffers from the stigma of being nuclear. Clean or not the accident possibility is not taken lightly. Ionic propulsion still needs some work, but is possible in the future maybe. Electromagnetic launch style may be feasible. It won't get you all the speed but could give you a leg up. Basically think putting the orbiter in an enormous rail gun, there's a style of railgun this can function with (I think I've seen it before).

As for credientials, I'm an aerospace engineering student who's been working orbital mechanics for a while. I've studied rocketry in my time at school, so I understand some of the principles. Anyway, thanks.