Earl Colby Pottinger wrote:

I find that hard to believe, first the ROTON was already a large move away
from standard US designs even after they oved to the Fastrac engine. Second,
we don't need NASA-type super expensive junk as boosters, just something that
develops lots of thrust. While I admit large hybrids may have hidden
got-yous, what about pressure feeded peroxide rockets. Remember I mean
boosters only! The ROTON people already had access to a working peroxide
engine, they already made composite tanks. No regulator, fill the tanks two
thirds and pressurize them, simple valves to turn them on, the ROTON does the
steering and the boosters may or may not have a recovery system, your choice
based on costs.



Oddly, the hydrogen peroxide option occurred to me also after I wrote
the last post; there would be at least three ways of going about it;
each with their pluses and minuses:
Simple catalytic decomposition of hydrogen peroxide into superheated
steam and oxygen- this would be very easy to accomplish, and very
reliable...but the ISP would suck, and the weight of the pressurized
peroxide tank would make for a pretty inefficient design in regards to
weight versus performance.
but the weight of the tankage would still be quite high...although if
ocean recovery of the spent boosters was intended, pressure fed hydrogen
peroxide and a fuel- such as kerosene- which burns with the oxygen freed
in the catalytic reactions the hydrogen peroxide decomposes; this would
also be very simple and reliable, you would get a better ISP than the
first option, their inherent toughness might be an advantage.
A hydrogen peroxide/fuel driven engine using the hydrogen peroxide both
as an oxidizer; and via its decomposition as a method of driving a
turbopump for propellant feed- this is a more involved process, but has
the advantage of a better ISP and lower booster weight in regards to its
thrust- the technology was already proven by both the Germans during
W.W. II with the Walter motor for the ME-163 Komet rocket fighter:
http://www.walter-rockets.i12.com/hw/sitemap.htm and the British Gamma
motor as used on the Black Arrow satellite launcher:
http://members.aol.com/nicholashl/ukspace/htp/htp.htm
the technology is fairly basic, and the high density of hydrogen
peroxide in comparison to LOX makes for more compact tankage.
It well be interesting to see how well the simple hybrid motor for
Rutan's Spaceship One performs in actual operations, if it is reliable,
such motors may combine the simplicity of solids with both a (somewhat
inefficient) throttlable aspect- as well as safe in-flight shutdown via
stopping the oxidizer flow.

Pat