From: utzoo!decvax!cca!David.Smith@CMU-10A@sri-unix
Newsgroups: net.space
Title: X-20 reentry
Article-I.D.: sri-unix.1875
Posted: Thu Jun 24 11:15:11 1982
Received: Mon Jun 28 01:21:33 1982

The X-20 wasn't called Dyna-Soar (Dynamic Soaring) for nothing.  It was
to be fully reusable, and didn't use ablative heat shields.  The method
of atmospheric entry was to come in at a shallow angle until it got hot,
then to aerodynamically pull up, leaving the atmosphere to radiate the heat
away.  It would skip off the atmosphere many times as it slowed.  When
it was going slow enough, it would come on in.

About ten years ago, I saw a drawing of a proposal North American
Aviation had made for a Super-X-15.  It was bigger than the existing
ones;  I don't know what they proposed to do for a heat shield.  The
drawing showed it being launched on top of an Atlas.