the drive to explore

On 11 Jun 2005 08:41:41 -0700, in a place far, far away, "horseshoe7"
made the phosphor on my monitor glow in such a
way as to indicate that:

Anything that can carry passengers can carry cargo instead. The
problem with STS was that it was designed to take few crew, and a lot
of cargo. That's completely different than a vehicle that's designed
to take an equal amount of either.

Now that you finally get around to describing some little part of your
design - I'm sorry to say, but that is absolutely ridiculous.

I doubt if you're sorry to say it, but you're mistaken in any event.

You are
proposing to man-rate an entire passenger/cargo area in today's
technological/industrial/political enviroment?

No, as I've said, I wouldn't "man rate" a space transport, because
that's an oxymoron (though I'm not sure what the
"technological/industrial/political environment" has to do with it.
I'd design it to be reliable.

And, for what reason?

To reduce the cost of access to space.

There currently is no customer, and there is no requirement.

There are millions of customers (i.e., people who would buy a ride to
space, if offered at the right price).

You are
attempting to have government FORCE a requirement on industry and
customers that doesn't currently exist, and doesn't need to exist yet.

I'm not attempting to have the government FORCE anything. Once again,
you're listening to the voices in your head, instead of reading what I
write.

rest of cluelessness and irrelevance snipped

On Sat, 11 Jun 2005 16:23:25 GMT, in a place far, far away,
(Alan Anderson) made the phosphor on my monitor
glow in such a way as to indicate that:

But if the tourism vehicle exists, it would make no sense to not use
it to deliver astronauts, just as they (usually, except when flying
T-38s) fly coach today. The amount of "room" would be a function of
spaceline that was using it (just as American increased the pitch on
their seats for more legroom a few years ago).

That's not entirely obvious. There can be tourist-optimized designs that
don't really make sense for general passenger delivery.

For example, note the difference in structure between a modern
double-decker railroad car designed from the beginning as a tourist
vehicle and an older one built around the same general plans as a regular
passenger car. It would not be either easy or economical to gut the
tourist-specific design and refit it with commuter seats; the whole thing
is *designed* around maximizing the view for the passengers, and the frame
doesn't readily support a different way of putting in seats.

Perhaps, but you make my point. The "railroad car" is the thingie
that's designed to go into the payload bay of the transport, so you
might indeed have a different one for tourists than for commuters, but
that still wouldn't affect vehicle design per se.

horseshoe7 wrote:
Rand Simberg wrote:
glowed:
You are
attempting to have government FORCE a requirement on industry and
customers that doesn't currently exist, and doesn't need to exist yet.

I'm not attempting to have the government FORCE anything. Once again,
you're listening to the voices in your head, instead of reading what I
write.

It is extremely difficult to attempt a rational conversation with
someone who downplays the difficulty of orbital reentry, can't deal
with EELV/CEV as reality, and continously proposes ideas for which
there is no current requirement or customer.

Here's a good article on orbital vs. sub-orbital spaceflight and
atmospheric reentry:
http://en.wikipedia.org/wiki/Differe...l_spaceflights

Hey, Stewart, you're arguing with a professional aerospace engineer
there (Rand), and as another professional aerospace engineer here
(me) I'd like to step in as well.

Rand's normal place of residence is sci.space.policy; there, you find
people whose qualifications range from interested but uneducated
amateur to professional active aerospace engineers and vehicle
designers. While wikipedia is a source of interest, much more
interesting and detailed discussions starting with say the actual
vehicle ballistic coeficient, shape, hypersonic lift to drag ratio
and thermal protection system materials are not uncommon.
For any serious work, the wikipedia article is at best the introduction
and at worst a slightly misleading starting point for a professional
studying the reentry trajectory, maneuver dynamics, aerothermodynamics,
and thermal protection system materials selection. I'm much more
worried about how to extend and control my equilibrium glide and
peak heating rate at the nose of the vehicle than what the wikipedia
says about the problem.


For a certain subset of the orbital and hyperbolic reentry problem,
vehicle shape problem, and ablative thermal protection systems
solutions, it's really well understood and really quite robust.

Ablative thermal protection systems, using for the most part phenolic
resins and various fillers, are a commercially available product.
They're not exactly off the shelf unless your vehicle looks exactly
like someone else's in weight and configuration and size, but the
vendors that do it are perfectly willing to take reasonable amounts
of money and turn it into a properly engineered and fabricated
heatshield assembly. There are multiple commercial vendors who
will do the whole assembly, and some who just provide ablator materials
for use by others assembling the vehicles. Despite the rather low
volume of material used each year, the total cost of the materials
is still fairly low.

Without divulging current commercially sensitive information,
the cost of the TPS system engineering and production for the
last commercial manned reentry capsule someone attempted to
build (METEOR/COMET) was well under a million dollars according
to sources both at the vendor and at the purchaser (1991 dollars,
I think).

The dynamics of a controlled lifting reentry are a design issue,
and control issue, and a manned vehicle is going to be designed
to use a controlled lifting reentry under almost all circumstances.
And there are other complicating factors. It's not a cookie dough
stamp out project. It takes some real engineering.

But the quantity of effort required has fallen to quite reasonably
small values, which people are doing routinely now, and are quite
good at doing and crosschecking with other vendors and consultants.

It is only in the tantalizing allure of reusable TPS systems
like Shuttle uses that you get into overly expensive and hard
to qualify and fragile solutions. And there is no law of nature
that says that reusable vehicles can't use expendable / replacable
ablative heatshields.



-george william herbert

Erik Max Francis wrote:
horseshoe7 wrote:

The ironic thing is, the Chinese will probably be the next to walk on
the moon... maybe then we Americans will get off our asses again, ...

It's not very likely that the Chinese merely managing to successfully do
something we did thirty years ago is going to inspire much of anything.
They'd really have to get embarassingly far ahead of the United States
for that to be at all motivation, particularly if they were perceived as
a serious threat, to get any kind of second space race.

Their space program _is_ officially directed at establishing a
Moonbase. Is that "embarassingly far ahead" enough?

Sincerely Yours,
Jordan

On 11 Jun 2005 13:55:01 -0700, "Jordan"
wrote:

Erik Max Francis wrote:
horseshoe7 wrote:

The ironic thing is, the Chinese will probably be the next to walk on
the moon... maybe then we Americans will get off our asses again, ...

It's not very likely that the Chinese merely managing to successfully do
something we did thirty years ago is going to inspire much of anything.
They'd really have to get embarassingly far ahead of the United States
for that to be at all motivation, particularly if they were perceived as
a serious threat, to get any kind of second space race.

Their space program _is_ officially directed at establishing a
Moonbase. Is that "embarassingly far ahead" enough?

If they ever do it, yeah, that would kick things off.

Rand Simberg wrote:

Transportation is transportation, but there is transportation and then
there is transportation. Most people throw away their car after using
it for 200 Mm or so. That is the distance of about 5 orbits.


Because there is little difference in wear between five and fifty
orbits? Because you're making an absurd analogy?

Are you being deliberately dishonest? Or do you have trouble with
reading comprehension?

--
Hop David
http://clowder.net/hop/index.html

Jordan wrote:

Their space program _is_ officially directed at establishing a
Moonbase. Is that "embarassingly far ahead" enough?

Since they've barely gotten into orbit, no.

--
Erik Max Francis && && http://www.alcyone.com/max/
San Jose, CA, USA && 37 20 N 121 53 W && AIM erikmaxfrancis
And there inside our private war / I died the night before
-- Sade

Rand Simberg wrote:
On Sat, 11 Jun 2005 14:03:42 -0700, in a place far, far away, Hop
David made the phosphor
on my monitor glow in such a way as to indicate that:



Rand Simberg wrote:


Transportation is transportation, but there is transportation and then
there is transportation. Most people throw away their car after using
it for 200 Mm or so. That is the distance of about 5 orbits.


Because there is little difference in wear between five and fifty
orbits? Because you're making an absurd analogy?

Are you being deliberately dishonest? Or do you have trouble with
reading comprehension?


Neither, as far as I know.

Reading comprehension, then.



--
Hop David
http://clowder.net/hop/index.html

On 11 Jun 2005 11:27:50 -0700, in a place far, far away, "horseshoe7"
made the phosphor on my monitor glow in such a
way as to indicate that:

You are
attempting to have government FORCE a requirement on industry and
customers that doesn't currently exist, and doesn't need to exist yet.

I'm not attempting to have the government FORCE anything. Once again,
you're listening to the voices in your head, instead of reading what I
write.

It is extremely difficult to attempt a rational conversation with
someone who downplays the difficulty of orbital reentry

When did I do that?

I find it extremely difficult to have a rational conversation with
someone who claims that I write things that I didn't, by simply making
them up out of whole cloth.

, can't deal
with EELV/CEV as reality

I have never denied that they are a reality. I get paid to work on
them. You, on the other hand, weren't even aware of their existence
(at least of the latter) until a few days ago. And yet you want to
parade yourself as an expert in a knowledgable newsgroup?

Again, you're apparently arguing with someone else, a person who
doesn't seem to exist to the rest of us, instead of me. You might
want to check your medication dosage.

, and continously proposes ideas for which
there is no current requirement or customer.

There are customers, sorry. Your denial of them doesn't make them go
away. And the customers generate the requirements.

Here's a good article on orbital vs. sub-orbital spaceflight and
atmospheric reentry:
http://en.wikipedia.org/wiki/Differe...l_spaceflights

I'm already quite familiar with that, thank you. I analyze such
things for a living.

"horseshoe7" wrote in message
ups.com...

Someday, perhaps in another 50 years, something like
what you are describing will be successfully built.
However, we aren't advanced enough technologically,
industrially, or politically to design and build such a
system yet. Have patience, for Pete's sake.

For my sake, please don't. We have the technology and industrial
capacity for CATS, what we lack is the political/market will, though the
economic case is closing.

The shuttle derived HLV is a job reclamation program, pure pork. It
serves to perpetuate existing unsustainable cost structures, (the
standing army), it is not going anywhere. It now seems probable it will
be commercially superseded before it gets completed. Low cost is
primarily about high flight rate and NASA is actively going in the
opposite direction. There is not currently a rocket a day market for
HLV.

The good news is this comprehensively removes NASA from the launch
industry and I expect investment in new genuinely low cost commercial
launch initiatives is already sharply increasing. If NASA had opted for
an EELV approach this cold war would have been greatly extended. NASA
will still require launch vehicles and this sizable market will now
quickly open up.

A part of me wonders if someone somewhere might not have intentionally
planned all this, it seems too perfect.

Pete.