🚀 go-pugleaf

> Retarding SSTO, Edward V. Wright writes:
>
> Advances in technology, perhaps, but hardly recent advances.  The old
> Saturn S-IVB stage could've been turned into a SSTO launcher, with a
> payload the size of a Gemini spacecraft.  The "unattainable mass ratio"
> is nothing more than an aerospace legend.
>


        This somewhat confuses the issue, in that it tends to imply that the
technology necessary to build a DC-1 was available a generation ago.  The
S-IVB derivative would be a ***non-reusable*** SSTO, which is a different
animal than a ***reusable*** SSTO.   In order to recover your hypothetical
S-IVB vehicle, you will have to add equipment for recovery and landing,
including a retrofire system, heat shielding, parachutes (or the fuel and
throttable engines for a powered descent), landing gear (or waterproofing of
all systems), etc.  The extra mass will kill your payload.

        What is really hard is not making an SSTO, but making a "RRSSTO" or
Recoverable Reusable Single Stage to Orbit which has enough payload to
justify its costs (however accounted for).




--
Bruce Dunn    Vancouver, Canada   Bruce_Dunn@mindlink.bc.ca