In article , wrote:
A hundred fold decrease in cost is a HUGE decrease...

Definitely so. That sort of massive improvement has never been done in
one leap before. On the other hand, to quote the late Max Hunter (chief
engineer for the Thor IRBM, later the basis of Delta), when that comment
was made to him: "The human race has never done anything as stupid as
we've done in space."

No major advances in basic propulsion science, i.e. no dilithium crystals,
impulse drive or anti-gravity engines nor is there likely to be. Chemical
rockets are going to be around a long time.

Probably so, but that doesn't mean that chemical rockets are in a state of
perfection which permits no major improvements. Too much of the accepted
wisdom in chemical rocketry is just the first thing that happened to work
when people were in a hurry in the 1950s. The alternatives are poorly
explored, and the current technology is in no way optimum.

Also, "nor is there likely to be" is gross hubris. If you added "soon" to
that, I might agree, with reservations.

No economies of scale and highly unlikely space craft will ever be mass
produced like Toyotas.

There won't be mass production of spacecraft without major improvements in
propulsion, which probably won't happen soon. But there is plenty of room
for somewhat lesser economies of scale. Having reusable spaceships merely
cost as much as major airliners would be a massive improvement... and
there is no clear reason why they couldn't, since they should actually
be simpler.

Since it is so expensive, only governments can afford to do it...

An increasing fraction of space launches are for private customers, and
there have already been privately-developed space launchers (a few).

If you assume that development of a reusable spaceship has to cost
billions and billions, then definitely only government can do it. But
that is an assumption, not a self-evident fact.

That's not to say costs can't be reduced, just that it is unrealistic
to expect a couple of orders of magnitude reductions.

I would say that a more accurate statement is that it is difficult to
*prove* that such a reduction is possible. The notion is not ridiculous;
even high-performance experimental aircraft typically operate at only
perhaps ten times their fuel costs... and that is *several* orders of
magnitude better than today's rockets. There is no obvious law of nature
which prevents reusable rockets from getting down into the same range.
--
MOST launched 30 June; science observations running | Henry Spencer
since Oct; first surprises seen; papers pending. |