On Mon, 6 Oct 2003 18:56:24 GMT, (Henry Spencer)
wrote:

In article ,
Christopher wrote:
There's lots of unexplored potential left in chemical rockets, actually.
Very little serious R&D has been done on them in the last forty years,
other than (basically) incremental refinements of early-1960s designs.

The SSME uses hydrogen and oxygen, and that's a pretty good
combination for fuel.

Actually it's not a terribly good combination, except for some specialized
purposes. Hydrogen is a lousy fuel; people are mesmerized by its high
Isp, and forget the heavy tanks and plumbing and the poor engine T/W.
What we care about is delta-V, not Isp, and the former is often actually
easier to get with fuels like kerosene.

Could the shuttle go up just as well using paraffin/kero and lox the
same as with it's current hydrogen fuel?

Even setting that aside, note that the SSME is an incremental refinement
of Pratt&Whitney's 1960s RL20/XLR129 high-pressure-engine work. Nothing
very new there.

Didn't know that.

The improvements to be had are (with possible minor exceptions) not in new
fuels, but in better engines -- higher expansion ratios with altitude
compensation, lighter weight, longer operating life, lower costs.

So, what your saying is rocket engines could be developed like the
internal combustion engine has been, in that the car engine of 1963 is
a totally primative engine compaired to the 2003 car engine as we have
seen 40 years of development take place?


Christopher
+++++++++++++++++++++++++
"Kites rise highest against
the wind - not with it."
Winston Churchill