🚀 go-pugleaf

In article <19069@mindlink.bc.ca> Bruce_Dunn@mindlink.bc.ca (Bruce Dunn) writes:
>> No, some of the S-IVB-based SSTO proposals were reusable...
>
>        I stand corrected, although somewhat puzzled. If you have the details
>handy Henry, could you inform us how it was planned to recover a cylindrical
>stage without having it break up the way the Shuttle ET breaks up when it
>hits the atmosphere?  Presumably this must involve some mechanism for keeping
>the stage oriented and tumble free during re-entry.  What heat shield
>materials were planned in this era prior to the Shuttle tiles and blankets?

I don't have a lot of detail.  The proposal I recall was in three phases.
Phase one recovered an S-IVB with minimal modifications (ocean recovery
using parachutes and retrorockets) as a demonstration, using the stage's
existing RCS system plus three steel-mesh ballutes for nose-first
stabilization, and ablative thermal protection.  Phase two switched to
land recovery, using landing legs plus crushable honeycomb behind the
heatshield.  Phase three did a substantial rebuild of the engine area
to use an aerospike engine, which doubled as a liquid-hydrogen-cooled
heatshield for tail-first reentry.  After phase three successfully
demonstrated an engine suitable for SSTO operations and a fully-reusable
recovery mechanism, an operational SSTO vehicle would be developed
using lighter structures etc.  (The version I saw sounded like they
weren't sure a direct S-IVB derivative could achieve SSTO itself.)
-- 
"God willing... we shall return."       | Henry Spencer @ U of Toronto Zoology
       -Gene Cernan, the Moon, Dec 1972 |  henry@zoo.toronto.edu  utzoo!henry