From: email@example.com (GCHudson)
Subject: Re: making the colonization of space cheaper
Date: 7 Mar 1998 05:49:48 GMT
<<Marcus Lindroos INF wrote:
: Boeing proposed water-cooling on VTOL landers during the 1970s. The
: principal advantage is easy "refurbishment" compared to other TPS
: options. VTOL vehicles have an advantage with water cooling since the
: heat pulse they see during entry is short and sharp, rather than
: protracted due to higher L/D entries. Water has been shown to be well
: suited to that low L/D trajectory.
Is there any good reason why General Dynamics (Millennium Express,1991),
JRS (Kankoh Maru, early 1990s), Boeing (SDIO VTVL SSTO study, early 1990s) and
MBB (BETA II, 1986) rejected the concept, favoring ceramic TPS instead?
Gary's reasoning sounds logical and convincing to me, so I am curious
as to why all base-first VTVL SSTO proposals don't use water-cooling.>>
Basically, because people are scared of "active" systems. This is particularly
amusing in light of the need to regeneratively cool most rocket engines, but
who said engineering analysts actually have to make sense? BTW, Beta I (1970)
proposed a water-cooled alternative heat shield, and so did the GRM-29A orbital
strike spaceplane proposed by MacAir St Louis as part of the SCIENCE REALM
project. RASV and Dyansoar both would have used "water walls" to cool the crew
cabins, gear wells, etc.
Gary C. Hudson