In article , (Wayne Throop)
wrote:

: So in a few years, we're looking at a flight rate
: orders of magnitude higher than what we have now. Even if this is
: suborbital rather than orbital, this will result in a much faster
: feedback & revision cycle, and so faster progress.

My problelm with this one is that you can revise and improve suborbital
flight all you want, and you're still no farther along than the X15 was,
in terms of basic capability.

No, that's not the case. Improving suborbital flight could mean many
things, I suppose, including reducing cost and improving reliability (I
might argue, for example, that SS1 is already well beyond the X-15 in
terms of reliability, though there's certainly room for lively debate on
that one).

But when you consider what direction the market forces are likely to
push, it's almost certainly going to be for higher, faster, longer
microgravity flight profiles. And continued revision and improvement in
this direction leads directly (yet incrementally) to orbital flight. So
you can't "improve suborbital flight all you want" and be no further
than the X-15; at some point you've improved it well past the X-15 and
into the orbital realm.

Is there some reason to think this will spill over to orbtial capability?

There's the direct incremental improvement noted above. In addition,
many of the problems faced by suborbital craft are similar or the same
as those faced by orbital craft: the need for a reaction control system,
for example. Also cabin pressurization, non-airbreathing engines, all
components being rated for use in space, TPS (though admittedly to a
much lesser degree, and somewhat depending on other craft parameters),
and so on. A high flight rate, with accompanying rapid progress on
these fronts, certainly makes the overall problem of building an orbiter
easier, don't you agree?

: - Once the cold war rivalry as justification for space development
: evaporated, the space community seized on science as its raison
: d'etre. This was a mistake; space science is almost entirely pure
: research, and there isn't much money in that (in the short term
: anyway);

My problem with this is that there has been lots of money to be made for
less costly launch capability for some time.

Yes, the market has been there, but it hasn't been recognized until
recently. Moreover, the very idea that private companies could run
their own space program was met with nothing but giggles until about 5
years ago. The giggle factor is gone, making investment more possible;
and then of course we have the modern angels (Munsk, Bezos, etc.)
serious about doing it themselves.

Slots for comm satellites,
weather satellites, mapping satellites, and on and on.

Tosh. These are a small market, and don't demand a high flight rate,
and have been supplied mainly by government launchers. Sure, they would
have been better off with cheaper launches -- and this is an angle
SpaceX is taking even today -- but the existing expensive launches were
good enough; these customers were not price-sensitive, and the volume
was too low to drive much in the way of real competition.

Human passengers, in contrast, will (after the early adopters) be rather
price-sensitive, and will be flying in high enough volume to drive
competition. This is a completely different sort of market. Groping
for analogy here, consider the ocean liner industry as compared to the
auto industry. The latter advances much faster.

It is possible that
governments block progress, such as insisting that the Shuttle program
can and should do everything. But even so, if somebody else could launch
for a lower price, I don't think they'd have problems getting customers
away from the Shuttle.

Andrew Beal might disagree, but I realize that opinions differ on
exactly what went wrong there. Still, I don't think that's the key
point; the key point is that satellites are not the right market for
driving any real progress.

Note: I'm wearing my skeptical hat here. I *do* see these points,
and agree that that they are positive. I am not merely dismissing
them, or even attempting to "refute" them. I'm just not very optimistic
on how much they will accelerate progress.

Sure, you're arguing in a rational, reasoned manner. I certainly have
no complaint with that -- indeed, this newsgroup could use a lot more of
it!

Best,
- Joe