Re: Surplus launch vehicles

From: Doug Jones (
Date: Tue Oct 17 2000 - 08:35:13 MDT

Adrian Tymes wrote:
> Jeff Davis wrote:
> > What do they do with these things, anyway, when they decommission them as
> > part of whatever arms control/disarmament agreement requires it? Anyone
> > know FOR SURE? Destroy them, would be my guess. But perhaps they're just
> > no good for "peaceful" purposes. Doug, spike? Anyone?
> Oh, they're good for "peaceful" purposes. They deliver a payload to a
> target; that can be used for good or evil. But, since their primary
> purpose is war, the danger that anyone seeking to repurpose them into
> useful stuff is actually just covering for acquisition of weapons is, in
> the minds of the ICBMs' current holders, too great to risk selling them.
> Or, at least, so I understand.

Perzackly- this is why the old Titan II's are only being used by the
USAF for smallsat launches, and similarly with the Russian ICBM
launchers. Also, the LEO payloads of these vehicles are poor since
their mission delta-V as designed was quite short of orbit.

> Besides, there's gotta be better ways than chemical fuels to achieve
> orbit.

Not really- rockets are remarkably efficient heat engines _when used at
high mass ratios_. The object in orbit can have kinetic energy over 50%
of the chemical energy in the tank on the pad.

> Get the fuel to achieve orbit to under 10% of the rocket's mass,
> and that alone would probably get you cheap access to space, relative to
> today's costs. (It'd probably be more due to reduced maintenance to
> reduced mass, than directly to reduced fuel costs, but cheaper is
> cheaper.)

Nope, fuel is cheap, the entire design concept has to be revamped to
take the best advantage of that. 1000 tons of LOX/kerosene, plenty to
put 10 tons of payload into orbit in two stages, only costs about
$150,000- or $150/kg of payload. Ammunition thinking, with severe
constraints on gross liftoff weight, is what gave us $5,000/kg

> So, what do rocket scientists call their not-as-tough-as-one-would-think
> problems?

"It's the business plan, stupid." The technology exists, the tough part
is making the right marketing decisions which then drive the design to
be economical rather than highest performance.

Doug Jones
Rocket Plumber, XCOR Aerospace

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