Re: Book, Single Stage to Orbit

Andrew Case wrote:
> The original Kistler proposal (before the "improvements") was a quite 
> nice TSTO with a dumb Launch Assist Platform that lifted the upper stage 
> clear of the atmosphere straight up.  The upper stage separated and the
> LAP dropped straight back down to the launch site.

Yes. You'll have noticed that they dropped this plan; I haven't seen 
anywhere why, but I think I know.

> I've always rather liked this idea

Me too; until I simulated it.

I told my simulation program that the first stage had to land trivially 
west of where it took off from- and by the way it had to be a trajectory 
that makes orbit (going east!) with the second stage. It found an 
interesting trajectory that relied on coriolis from the rotation of the 
earth that permitted it to give a small boost to the second stage, which 
then made orbit.

However, compared to a similar construction TSTO I found my payload 
dropped precipitously, by 75%.

That's *really* bad.

So I have to either build my launch vehicle 4x bigger or launch 4x more 
often. IMO neither seems like a brilliant idea. I think the costs go up 
by 4x, and then you have to claw it back by making your launch vehicle 
more reusable... but adding reusability also costs payload... it's 
rather a slippery slope.

Anyway, it wasn't just my program, since I've run my simulation I've 
learnt that apparently Boeing did a study in the 60s which showed much 
the same thing- doing this loses you 65-80% of your payload capacity.

At the end of the day, IMHO a conventional flyback booster scheme is 
probably the best solution for accessing space. I quite like SSTO also, 
but the payload size is likely to be small, and the margins thin.

Additionally, tethers also look pretty promising too; SSTO to a skyhook- 
that works- or even just climbing up the space elevator- some people 
think that a practical space elevator cable technology is only about 2 
years out- the materials science is looking *very* promising.

> ......Andrew