Re: Re: Book, Single Stage to Orbit

Ian Woollard wrote:
> That's why payload is important, because it provides income that leads
> to profit; and that's why I'm concerned about a 4x reduction in income
> per flight. My gut feel is that the profit margin isn't necessarily a
> factor of 4 over cost in the first place.
> [ .. ]
> The other, perhaps better way to go is to differentiate the market and
> command a higher price per kilogram- it may not matter if it is 4x more
> expensive if it means you can launch a spy sat every half an hour or
> something. If having a well designed, simple LAP can do that, then it
> might be a preferred system after all. Or something.
> 
> > The devil is in the details.  You have to
> > make common assumptions about design parameters
> > and then compare apples and apples.
> 
> Sure. But this payload reduction seems to be rather important, and I was
> getting the impression people aren't completely getting the implications
> of this particular architecture.

As you suggest in the second paragraph above, "value per flight" is not
necessarily proportional to "payload _mass_ per flight". A flexible, available
capability for launching even a very mass-constrained payload (especially
if it can be done on very short notice) may have a value out of proportion
to the raw payload mass in certain situations.

(This may well drive a diversity of vehicle designs, depending on how the
economics of various missions work out.)

-dave w