🚀 go-pugleaf

In article <ewright.726166318@convex.convex.com>, ewright@convex.com (Edward V.
Wright) says:
>
>In <93002.220235SAUNDRSG@QUCDN.QueensU.CA> Graydon <SAUNDRSG@QUCDN.QueensU.CA>
>writes:
>
>>What I understood Bruce to be proposing/discussing was the idea of
>>building a bottom stage for a DC-1 for those occaisons when a 'heavy'
>>payload needed launch.  (Heavy - either something that grosses out
>>long before it bulks out the cargo bay, or something that is going
>>higher than LEO on one launch (for whatever reason)).
>
>I understood that too.  Perhaps you did not understand what I meant
>when I said, if there are enough heavy cargoes to justify a new
>vehicle, it would be more cost-effective to build a larger SSTO
>than a two-stage kludge?

Rather depends on how many heavy cargoes there are, doesn't it?

As I understand it, the point to an SSTO is to make expendables
non-cost effective.  So there *won't* be another vehicle fairly
soon after DC-1's get flying in numbers if they work as advertised.

If there's one or two heavy cargoes a year, Bruce's quick and simple
second stage might make a great deal more sense than scaling up
an SSTO design by a factor of five, which I would expect to be quite
difficult, since it's a complete re-design and probably needs new
engines.

A company with three or four bottom stages could happily specialize
in lifting other people's DC-1s with heavy cargos (land your DC-1
next to their stacking facility after its last trip up) and make
decent money at it if there were enough cargoes ('enough' quantified
after someone does a real design study for the thing and provides
some numbers for things that need to go up in one piece and weigh
between 10 and 50 tons.)

Why would you expect the design effort for a factor five scale up
to be less expensive?

Graydon