Heard too much and need to vent.

"Rand Simberg" wrote in message
...
On Sat, 26 Jul 2003 04:33:21 GMT, in a place far, far away, "Dave
O'Neill" dave @ NOSPAM atomicrazor . com made the phosphor on my
monitor glow in such a way as to indicate that:

Sometimes wasting money can be very useful.

It's never as useful as spending it productively.

That can be harder to establish than it seems. One problem is that there
is
obviously something of a question mark about what "productively" means.

Increases the GDP by whatever yardstick one is using.

In that case a localised "waste" of money can certainly achieve that.

Money is rarely really "wasted"

Are you sure Bush is a Republican?

Yes, but he's no conservative...

People here say the same about Blair's socialism. Although that might
yet
bite him in the arse.

I'm still taking odds on him not surviving the summer ;-)

I wouldn't necessarily take that bet. Statesmen sometimes lose office
after the war (e.g. Churchill).

I think Blair has brought a whole different mess of trouble onto himself
than Churchill did.

If he does go (which isn't certain, Campbell might satisfy the wolves) he
won't get a second chance.

On Sat, 26 Jul 2003 06:30:22 +0100, in a place far, far away, Cardman
made the phosphor on my monitor glow in
such a way as to indicate that:

There was no explosion in Challenger, initial or otherwise. Do you
never tire of flaunting your ignorance?

Well I have no idea what you are on about.

Yes, because you remain utterly innocent of physics.

Why do I smell a troll?

Perhaps because of the close proximity? I smell me, you smell you...

Thank you, but I am quite good at physics. And I see that you did not
care to explain your pointless ramblings.

I will assume that you cannot.

I will assume, based on ample evidence, that you are an utter ass.

So if there was no explosion, then why are they dead?

Do you believe that the only possible cause of human death is
explosions?

When have I said that anyone has died from an explosion? Never.

rolling on the floor laughing

Certainly in this case it was what made their death certain, but what
they really died from I cannot say for sure. High speed impact with
sea water seems the most likely cause.

There was no explosion. Go look it up.

--
simberg.interglobal.org * 310 372-7963 (CA) 307 739-1296 (Jackson Hole)
interglobal space lines * 307 733-1715 (Fax) http://www.interglobal.org

"Extraordinary launch vehicles require extraordinary markets..."
Swap the first . and @ and throw out the ".trash" to email me.
Here's my email address for autospammers:

Cardman wrote:
(Rand Simberg) wrote:
glowed:
That does make me wonder about the survival odds of such a ground
based explosion, when after Challenger we know that it was not the
initial explosion that killed them.

There was no explosion in Challenger, initial or otherwise. Do you
never tire of flaunting your ignorance?

Well I have no idea what you are on about. So if there was no
explosion, then why are they dead?

You have a lot of the general outline right, but several details
wrong.

On launch due to the cold one of the o-rings did not respond fast
enough to the sudden heating.

The O-rings were the secondary and tertiary backups for the primary
gas sealing zinc chromate putty. The O-ring not responding
fast enough was it failing to do its job, after the primary
mechanism had already failed, for numerous reasons regarding
how the boosters were designed, assembled, and tested.
But the attention on the O-ring is a misnomer. It was
not the gas seal; it was the emergency backup gas seal,
and several things had to go wrong first before it even
came into the picture.

As a result a leak occurred, where this
leak over time increased burning through the boosters support strap.

Right.

As a result the booster collided with the main tank puncturing it

Right. Most precisely, the rear attach point came loose,
it pivoted around the front, and the nose of the SRB impacted
the LOX tank in the front of the external tank. At the same time,
the damage at the rear of the external tank and the SRB breaking
loose and pivoting caused the aft end of the hydrogen tank in
the external tank to basically all fall off, breaking that tank
open as well.

and causing the fuel to explode, which then destroyed the main tank and
the attached shuttle.

The fuel did not explode. The tank broke up due to multiple massive
localized structural failures, at the rear due to damage associated
with the burnthrough and then the SRB separation, and at the front
due to the SRB nose hitting the LOX tank.

The two fuel components were at that time leaking / spraying into
the airstream, and downwind they mixed and burned very fast,
but there was no detonating explosion, and the tanks did not
explode they merely broke up / fell apart. By the time that
the LOX and LH2 were burning, the shuttle was already starting
to break up.

The shuttle came off the external tank stack first at the nose,
due to the failure of the front of the external tank, and then
at the rear. It pitched up sharply into the airstream due
to the sequence of the failure, and the high speed airflow
caused it to break up immediately. Note that, despite what
most people think, the shuttle had already broken up by the
time the fireball reached it. The nose, wings, and tail were
all separate pieces as the fireball of burning LH2 expanded
around them. What destroyed the shuttle orbiter was that it
came up off the external tank stack in an uncontrolled manner,
into a hypersonic airflow, at such a high angle of attack
that the air pressure just broke it to bits. Pop. Game over.
The fireball was irrelevant to the shuttle orbiter breakup,
and happened after it did. It didn't even really damage the
pieces that were left (and wouldn't really have damaged the
orbiter had it miraculously somehow not broken up).

Anyway, I never said that there was any explosion in Challenger, only
that the Challenger was destroy due to a near by explosion.

No explosion. Breakup of ET, shuttle orbiter loose into airstream,
shuttle orbiter breaks up, more or less simultaneously with that
the ET fuel fireballs, but completely independently.

The crew compartment was still fairly intact after this though,

Yes.

where it must have been interesting if NASA locked away the tapes.

There were almost certainly no tapes. All of the power for the
crew compartment came from fuel cells located elsewhere in the orbiter.
When it broke up, the power failed completely. That various
conspiracy theorists think there were tapes does not make it true.


-george william herbert

On Sat, 26 Jul 2003 04:37:33 GMT, "Dave O'Neill" dave @ NOSPAM
atomicrazor . com wrote:

"Cardman" wrote in message
.. .
First there is exploration, where there are never too many hills to
climb or rocks to upturn, then as an extra all those direct meteorite
impacts I am sure would prove interesting. Then there is the unknown,
where I am sure that there would be a few surprises on the Moon.

So? The same applies to the Earth.

Very nice, but the Moon is a pristine environment, which has preserved
many events for millions of years.

The earth is vastly different, when the atmosphere stops all except
the larger objects getting through. Not to forget that the weather is
very good at breaking things down.

So you can learn a whole lot about the evolution of the solar system
and our Sun from studying the Moon.

You could also find evidence of aliens... even if that is a long shot.

Second of all is making us of the resources, where I simply would have
to have a foundry and smelter on the Moon. So we can refine and
collect all the Lunar resources for later use, which can certainly
include HE3.

All of which are currently available significantly more cheaply on Earth.

You don't understand my point.

Out of the Earth and the Moon, which one can get say 50 tons of
aluminum into Earth orbit the cheapest?

The Moon would be it, once you had refined these resources.

So getting those resources on the Moon will greatly decrease costs
once you need them anywhere beyond the Earth.

He3 excepted, but given there are no He3 Fusion reactors and nor are their
likely to be for another century or so, your desire isn't all that
important.

Well it could be a lot earlier than that, where it would stop all the
Chinese taking it all. ;-]

My point is that if you are on the Moon, then it is worth picking some
up. It's rare and it's there.

snip stuff

Yes you could do all this, but there isn't a reason to beyond your wish to.

Sure there are tons of scientifically valid reasons behind it.

1. It is easier to build/assemble telescopes on the Moon.
2. You can build far larger telescopes on the Moon.
3. It is a damned lot easier to service and upgrade your large
telescopes on the Moon.

If hubble had been on the Moon it would be ten time larger with
improve data results and could be serviced and upgrade without sending
out on an expensive Shuttle flight.

An astronaut would walk over to Hubble #2 pull out one module, put in
the new one and walk away. Upgrade done.

Also what people here like ignoring is that NASA already has a 100 ton
HLV, where they are just launching the "Shuttle" on it. So had I a
magic wand and turned the Shuttle into the Shuttle-C, then could you
still do your four launches a year, where we just use all the spare
cargo space to launch something useful and cheap like fuel.

Except it really doesn't work like that.

And how about an explanation?

As do I really have to spell out how useful a couple of hundred tons
of fuel in orbit would be in the near future?

Yes.

Raising the ISS once the Shuttle can no longer do it, when our
expanding atmosphere tends to give NASA a headache.

Since the likes of the OSP will have limited fuel, then if it wishes
to move elsewhere in orbit, then so would it have to refuel first.

And simply anything else that is passing by this location you could
refuel and send on its way. I don't know the future, but fuel is
always useful in it.

Keep the ISS raised no
problem, refuel the Shuttle to do that little bit more, move
satellites into high orbit for here and more.

Fuel, without a transport mechanism is useless.

Well this is all about if we had the Shuttle-C, which could certainly
transport hundreds of tons of it.

You'll also have to explain to me how you intend to store it.

Whatever cheap method that can store it and to allow fuel to be taken
out of course. And you can just rope it on to the ISS to keep them in
about the same location.

Sure it is not the best orbit in the world, but having that fuel there
you could still adjust to get your desired heading.

How?

Things call rocket engines. Yes it is wasteful going into that orbit
in the first place, but it is recoverable.

And had it been desired you could set up a small fuel station along a
much more useful orbit.

These things are easy to say, but far harder to do.

NASA's problem is going "oh its hard" and chickening out.

Just think that not that many years ago were men with vision who took
their astronauts to space and then to the Moon. And they even dared
think about such things like a 550 ton launcher.

Made in a damned shipyard as well.

I suggest some studying.

And I suggest stop saying "this is hard" and going out and saying
"were going to do this".

I mean anyone who has to ask me how to store fuel in space is clearly
not wanting to ever do it.

Cardman.

Cardman wrote:
Not counting on an engine out then?

Less to go wrong.

No redundancy.

Go with three smaller engines with the same total output, then if one
does fail, then you can still make orbit.

Four or preferably five. At liftoff, typical T/W is between 1.1
and 1.5; with three engines, you drop to T/W of between 0.7 and 1.0
if you lose one. With four, between .84 and 1.15; with five, between
0.88 and 1.2.

The excess thrust needed to get the margin above 1.0 and avoid
crashing back to earth if you lose one right after liftoff
is much more of a penalty with 3 engines than with 5.

The right number of engines for a rocket stage is arguably
bimodal, either one or five+. Note that a lot of stages
have been designed with 'the wrong number' of engines.
Multiple engines without engine out capability is just
multiplying the odds of engine failure.

This is all complicated by being interested in not designing
new engines all the time, as that is a large and painful
part of the overall launch vehicle development problem.
So having one the particular right size for your vehicle
on the shelf already may not be practical. A lot of people
go with two or three off the shelf or modified off the shelf
models rather than design a new 2-3x as big one.

Pressure fed engines don't have turbopumps to blow
up (the bits on the SSME's that have been redesigned several times
because they're so high strung)..

Maybe so, but other things can catch you out like "wiring".

If you want one engine then fine, but you can also explain what went
wrong when it fails to make space.

Failure statistics is both a theoretical and practical / observational
science, and contrary to your opinion, one engine is safer than two,
three, or most configurations with four engines, and many configurations
with five engines (less likely to lose one, though five plus engines
makes engine out much more practical).

With one engine, an engine out is catastrophic loss.

With two engines, an engine out is catastrophic loss, AND you have two
times as many engine failures.

With three engines, most engine outs are catastrophic losses, AND you
have three times as many engine failures.

With four engines, many engine outs are catastrophic losses, AND you
have four times as many engine failures.

With five engines, some or a few engine outs are catastrophic losses,
AND you have five times as many engine failures.

using LOX and kerosene (not RP-1), built out of steel in a shipyard,
not an aerospace contractor.

LOL. Has NASA ever asked for a price quote?

NASA and the Air Force paid a large number of companies to
research this area and produce concept designs in the late
1960s and 1970s. All of them produced what are generally
considered technically viable designs.

Research "Big Dumb Booster". To make it easy and cheap,
look at the copy of _LEO on the Cheap_ in PDF format at
Bruce Dunn's website:
http://www.dunnspace.com/leo_on_the_cheap.htm

Stop laughing and try to learn something.

Spoken by someone who does not know that RP-1 is Kerosene...
Rocket Propellant 1 (standard kerosene rocket fuel, MIL-P-25576)

RP-1 is Kerosene (meets the generic standards for that fuel),
but Kerosene is not RP-1. RP-1 is a much more picky blend
in the fractionalization process. As a result, it is several
times more expensive than random Kerosene, jet fuel, or diesel.

And I am sure those at the shipyard would point out that they could
work with the likes of aluminum as well.

Why? What's wrong with steel?

Weight considerations, where sure 8mm thick is good for that kind of
rocket, but on smaller rockets you will need thinner.

Are they skilled at doing thinner?

Um. Do you know what the Atlas I, II, III tanks are made out of?
In rough terms, 1mm thick stainless steel sheets, bent up and
welded...

There are steels with better strength to weight ratios than
any aluminum on the market (250ksi maraging steels beat the
best Al-Li or 7000 series Aluminum I know of). For membrane
tank designs it is purely a factor of weight to strength.
For integrally stiffened tanks, with stringers or the
isogrid / waffle patterns machined out, aluminum wins out.
For tanks where the tank is big enough that the walls are just
thick enough to be stable anyways, then it's back to weight
to strength ratio.

It's cheap, strong, and shipyards
already work with it (and charge far less than an aerospace company
would charge for a comparable aluminum structure). Quote:

Then why does not NASA use them all the time? :-]

A long and involved question to answer, partially answered
in _LEO on the Cheap_, partly in Dennis Jenkins' book
_Space Shuttle: The First 100 Missions_, partly scattered
in other sources. Basically, it wasn't sexy enough,
and reusable was initially thought to be near enough
that it would be cheaper. It was further away, and when
they knew that, they didn't stop and reconsider the
whole program and problem, but ploughed through with
a semi-reusable shuttle anyways.

The best part of this design, (from your HLV uber alles point of view)
was the 550 ton payload capacity.

Yes, amazing what you can do when you design for brute force. None of
this technical rubbish, when you just go with maximum fuel capacity
and a structure 175m tall and 23m wide.

None of this technical rubbish? What, exactly, do you think
makes and propels such a vehicle?

It's a lot simpler, and using mass instead of high tech and
low margins, but it's very technical. Trust me.

Too bad there is no need for payload capacities this large.

I would recommend pointing this design out to China, when one day they
would want something as huge and as cheap as this to launch their moon
base.

I have no doubt that _LEO on the Cheap_ and the various
contractor reports on the BDB concepts have received wide
foreign distribution.

And as I said NASA needs an end application, where launching something
in the direction of the Moon could give it one.

Congress will never let it.

Congress does not directly manage NASA, where NASA can certainly shift
about its resources.

.... uh.

Congress most certainly does directly manage NASA, tell it which
projects it can proceed with and which it can't. NASA has some
flexiblity and some discretionary funds, but Congress is very
definitely in the drivers seat.

This is an area where ignorance of the politics and government
structure are a really, really bad idea.

Look, here's our problem with you. Opinionated is fine.
Opinionated and not entirely educated is fine;
we have lots of people (including me, certainly)
who arrived here not fully educated experts in the
industry and have learned.

Opinionated and ignorant and not really showing much sign of
interest in learning, is a problem.

Space is Hard.

It's not as hard as some think and NASA sometimes makes it
out to be, but it is a hard, complex, highly technical,
highly political process. Even true experts take
decades to learn it. If you care, and you're making
enough noise that you seem to, then you *really* need
to get off your ass and start learning.


-george william herbert

Cardman wrote:

Well I have no idea what you are on about. So if there was no
explosion, then why are they dead?

Hint: people *can* die of causes other than explosions.

Paul

On 25 Jul 2003 23:13:13 -0700, (George William
Herbert) wrote:

Cardman wrote:
(Rand Simberg) wrote:
Well I have no idea what you are on about. So if there was no
explosion, then why are they dead?

You have a lot of the general outline right, but several details
wrong.

Interesting.

On launch due to the cold one of the o-rings did not respond fast
enough to the sudden heating.

The O-rings were the secondary and tertiary backups for the primary
gas sealing zinc chromate putty.

Wow I am surprised how both the news sources and even documentary
people got it wrong then.

The O-ring not responding
fast enough was it failing to do its job, after the primary
mechanism had already failed, for numerous reasons regarding
how the boosters were designed, assembled, and tested.

That still seems not how it should be, when there was then two
failures in this flight. So why did the putty fail on this flight and
not previous flights? Or did it and the O-Rings were just working
correctly in those cases?

But the attention on the O-ring is a misnomer. It was
not the gas seal; it was the emergency backup gas seal,
and several things had to go wrong first before it even
came into the picture.

Then some people need to correct their documentaries, when I recall no
mention of this fact.

And that sounds like a lot of failure to make you start to wonder if
someone stuck a screwdriver in it. I guess not though.

As a result the booster collided with the main tank puncturing it

Right. Most precisely, the rear attach point came loose,
it pivoted around the front, and the nose of the SRB impacted
the LOX tank in the front of the external tank. At the same time,
the damage at the rear of the external tank and the SRB breaking
loose and pivoting caused the aft end of the hydrogen tank in
the external tank to basically all fall off, breaking that tank
open as well.

So now you have your fuel and oxidizer a very short distance apart.

The fuel did not explode. The tank broke up due to multiple massive
localized structural failures, at the rear due to damage associated
with the burnthrough and then the SRB separation, and at the front
due to the SRB nose hitting the LOX tank.

The two fuel components were at that time leaking / spraying into
the airstream, and downwind they mixed and burned very fast,

I am not surprised.

but there was no detonating explosion, and the tanks did not
explode they merely broke up / fell apart.

Yes with fire and smoke all over the place.

By the time that the LOX and LH2 were burning, the shuttle was
already starting to break up.

I see.

The shuttle came off the external tank stack first at the nose,
due to the failure of the front of the external tank, and then
at the rear. It pitched up sharply into the airstream due
to the sequence of the failure, and the high speed airflow
caused it to break up immediately.

That I find a bit unexpected, when I would have thought that it would
be a little more tolerant to such a change. Sure not a lot of change,
but there was very little time involved to do much.

Note that, despite what
most people think, the shuttle had already broken up by the
time the fireball reached it.

Well this all did happen in a split second, when it was bang, no more
shuttle, and then the SRBs doing a good impression of devil horns.

The nose, wings, and tail were all separate pieces as the
fireball of burning LH2 expanded around them.

There sounds like a lot of burning there to have not counted as an
explosion. Some kind of "flash" effect I guess.

So find any unburned fuel in these remains?

What destroyed the shuttle orbiter was that it
came up off the external tank stack in an uncontrolled manner,
into a hypersonic airflow, at such a high angle of attack
that the air pressure just broke it to bits. Pop. Game over.

I will have to have a close look at that, when I would not have
expected the angle to be that much off when it broke up.

Also I will check on the speed, when after all this happened only when
they were starting to enter the upper atmosphere.

The fireball was irrelevant to the shuttle orbiter breakup,
and happened after it did.

Well if you say so, but having the oxidizer fall on the fuel tank
sounds unhealthy.

And there certainly would have been tons of the stuff there, when
Challenger was still near the start of the flight.

It didn't even really damage the
pieces that were left (and wouldn't really have damaged the
orbiter had it miraculously somehow not broken up).

So in the end both Challenger and Columbia went the same way, which is
failure of the air frame at hypersonic speed.

Does this not sound like a good case for a capsule design? As being
more rounded provides greater strength. If such a capsule could
survive a quick turn at hypersonic speed I don't know, but I could
foresee that it may.

And certainly there would be no burning, when it only lasted a
fraction of a second and would have had a pushing effect as expanding
hot gasses tend to do.

Also hypersonic airflow is bound to be very good at quickly
suppressing such a fire.

Anyway, I never said that there was any explosion in Challenger, only
that the Challenger was destroy due to a near by explosion.

No explosion. Breakup of ET, shuttle orbiter loose into airstream,
shuttle orbiter breaks up, more or less simultaneously with that
the ET fuel fireballs, but completely independently.

I admit to having trouble seeing it that way since these two events
would have been feet apart.

The crew compartment was still fairly intact after this though,

Yes.

So did they survive the initial break-up or not?

where it must have been interesting if NASA locked away the tapes.

There were almost certainly no tapes.

Well news sources reported tapes and they are usually reliable enough
to confirm it with NASA first. They usually start with the likes of "A
NASA spokes person said earlier today...".

I will check about for details.

All of the power for the
crew compartment came from fuel cells located elsewhere in the orbiter.

Elsewhere? Certainly they should be somewhere near where all the
electronic equipment is.

Also I would have thought that flight recording black box hardware and
even video in the cabin, would have had a backup power. After all it
is their job to study the break-up as it happens in such a worse case
situation.

When it broke up, the power failed completely.

Yes, but it would have been recording up to that point.

That various
conspiracy theorists think there were tapes does not make it true.

And yet reported by many reliable news agencies.

Maybe they were referring to a recording made up to the point of break
up, when NASA likes doing those.

Anyway, I would be very surprised if they was no video recording at
all from the cabin during this flight.

Cardman.

On 25 Jul 2003 23:41:54 -0700, (George William
Herbert) wrote:

Cardman wrote:

Go with three smaller engines with the same total output, then if one
does fail, then you can still make orbit.

Four or preferably five. At liftoff, typical T/W is between 1.1
and 1.5; with three engines, you drop to T/W of between 0.7 and 1.0
if you lose one.

Well losing one is the emergency situation, where you just have to
make orbit to succeed.

With four, between .84 and 1.15; with five, between
0.88 and 1.2.

Yes, but each engine you add also increases your possibility of an
engine failure.

1 engine = 100 flights.
2 engines = 50 flights.
3 engines = 33 flights.
4 engines = 25 flights.
5 engines = 20 flights.

So if in the one engine situation you suffered a loss each 100
flights, then in a five engine situation you would suffer a loss each
20 flights.

Also with a five engine system you would suffer the loss of two
engines each 400 flights. Not to mention that you can suffer unnatural
failure as well.

You can also go and add dozens of small rocket engines, where some of
them could give out on every flight.

The excess thrust needed to get the margin above 1.0 and avoid
crashing back to earth if you lose one right after liftoff
is much more of a penalty with 3 engines than with 5.

So how does the five engine system deal with two engine outs on this
400th flight?

The right number of engines for a rocket stage is arguably
bimodal, either one or five+.

I guess so.

Also, you can build in excess thrust capability, when engines also
last a lot longer if you don't keep thrashing the hell out of them at
106%

Ok, so that is the most efficient route to orbit, but taking slightly
longer does have some advantages.

Note that a lot of stages
have been designed with 'the wrong number' of engines.

Interesting.

Multiple engines without engine out capability is just
multiplying the odds of engine failure.

As I was working on above.

This is all complicated by being interested in not designing
new engines all the time, as that is a large and painful
part of the overall launch vehicle development problem.

Very true, but these new high reliability engines are tempting to
design a rocket to go on.

Five RS-84 engines would give 5320 thousand Lbs of thrust at sea level
and 5650 thousand Lbs in orbit.

That would make for one hell of a powerful rocket, but it would also
need a big fuel tank to feed it.

If you want one engine then fine, but you can also explain what went
wrong when it fails to make space.

Failure statistics is both a theoretical and practical / observational
science, and contrary to your opinion, one engine is safer than two,
three, or most configurations with four engines, and many configurations
with five engines (less likely to lose one, though five plus engines
makes engine out much more practical).

I just consider losing 550 tons of cargo a little unacceptable, where
some engine redundancy saves a very expensive bill.

With one engine, an engine out is catastrophic loss.

With two engines, an engine out is catastrophic loss, AND you have two
times as many engine failures.

With three engines, most engine outs are catastrophic losses, AND you
have three times as many engine failures.

Well the space shuttle made it to orbit after losing one engine late
into the flight.

So how does the SRBs affect all this? When I am starting to feel that
I should start counting the Shuttle as a five engine system. After all
it is aimed to only make orbit just about using all it has including
the SRBs.

There then would be my mistake in mentioning three engines.

With four engines, many engine outs are catastrophic losses, AND you
have four times as many engine failures.

With five engines, some or a few engine outs are catastrophic losses,
AND you have five times as many engine failures.

Yes I grasped that above when you mentioned going with five engines.

using LOX and kerosene (not RP-1), built out of steel in a shipyard,
not an aerospace contractor.

LOL. Has NASA ever asked for a price quote?

NASA and the Air Force paid a large number of companies to
research this area and produce concept designs in the late
1960s and 1970s. All of them produced what are generally
considered technically viable designs.

So why does NASA now buy their hardware from very expensive space
companies like boing? As I cannot see how they can charge $56 million
an engine if they are cloning them one after the other.

Highly technical yes, but still sounds too much.

Research "Big Dumb Booster". To make it easy and cheap,
look at the copy of _LEO on the Cheap_ in PDF format at
Bruce Dunn's website:
http://www.dunnspace.com/leo_on_the_cheap.htm

Noted.

RP-1 is Kerosene (meets the generic standards for that fuel),
but Kerosene is not RP-1. RP-1 is a much more picky blend
in the fractionalization process. As a result, it is several
times more expensive than random Kerosene, jet fuel, or diesel.

And I have a feeling that is done to stop your rocket engines from
clogging (coking?) up so easily. When I did have a good read of these
new engines like the RS-84.

Are they skilled at doing thinner?

Um. Do you know what the Atlas I, II, III tanks are made out of?

I do now.

In rough terms, 1mm thick stainless steel sheets, bent up and
welded...

Made in a shipyard? Or from one of those expensive space companies?

There are steels with better strength to weight ratios than
any aluminum on the market (250ksi maraging steels beat the
best Al-Li or 7000 series Aluminum I know of). For membrane
tank designs it is purely a factor of weight to strength.
For integrally stiffened tanks, with stringers or the
isogrid / waffle patterns machined out, aluminum wins out.
For tanks where the tank is big enough that the walls are just
thick enough to be stable anyways, then it's back to weight
to strength ratio.

Well that is more than I needed to know.

Then why does not NASA use them all the time? :-]

A long and involved question to answer, partially answered
in _LEO on the Cheap_, partly in Dennis Jenkins' book
_Space Shuttle: The First 100 Missions_, partly scattered
in other sources.

Then I will certainly be reading it soon enough.

Basically, it wasn't sexy enough,

Sexy enough? Well I don't know what NASA are up to, but if it comes
off the shelf or from a ship yard, then that sounds like a good price
in my books.

and reusable was initially thought to be near enough
that it would be cheaper. It was further away, and when
they knew that, they didn't stop and reconsider the
whole program and problem, but ploughed through with
a semi-reusable shuttle anyways.

I see.

So are they now going to be buying their rockets from ship yards? Or
am I correct in thinking that the smaller rockets are not their cup of
tea?

Yes, amazing what you can do when you design for brute force. None of
this technical rubbish, when you just go with maximum fuel capacity
and a structure 175m tall and 23m wide.

None of this technical rubbish? What, exactly, do you think
makes and propels such a vehicle?

Well if course it is technical, but I mean that this rocket is clearly
designed to burn up vast volumes of fuel, where it is mostly designed
to just survive this process.

So the cost is spent achieving the power and not to simply get the
last drop out of it. If you can understand that?

It's a lot simpler, and using mass instead of high tech and
low margins,

Exactly my point...

but it's very technical. Trust me.

Certainly, and I do.

Congress most certainly does directly manage NASA, tell it which
projects it can proceed with and which it can't. NASA has some
flexiblity and some discretionary funds, but Congress is very
definitely in the drivers seat.

Yes, but NASA does get to do things like divert funds and close
projects due to over spending.

And is this really a good idea? As should not congress provide fixed
funding for them to spend as they see fit. Then of course any extra
expenses like the ISS would need special request.

Well NASA does get to pick projects and terminate them, where it is
just that congress can override them. The Pluto mission comes to mind
along with extra funding.

This is an area where ignorance of the politics and government
structure are a really, really bad idea.

Well I am not a U.S Citizen, where such direct governmental control is
quite alien to me.

In fact I am frankly surprised that congress does not leave NASA to do
its own space, but after their bad record I can see why.

I guess I see something new about your country, when congress is a
pain in the behind for any government agency, when it always second
guesses them. In the end I guess that is what you call centralized
government.

Look, here's our problem with you. Opinionated is fine.
Opinionated and not entirely educated is fine;
we have lots of people (including me, certainly)
who arrived here not fully educated experts in the
industry and have learned.

Opinionated and ignorant and not really showing much sign of
interest in learning, is a problem.

I like learning, but only in areas that are useful.

So this LEO on the cheap is extremely interesting subject, which I
will certainly be reading up on. However, finding out everything about
the Shuttle is just a waste of my time.

As in that case I posed the simple idea of if the Space Shuttle could
be used as a space tug and kept in orbit. All it wanted was a quick
answer with a quick explanation as to why.

Being told to read the manual was therefore unhelpful, when I really
did not care if it could or not. A simple theory question, which took
a very long time to get the desired answer for.

As in the end the Space Shuttle is on the way out anyway, but one day
if I see the need I will really read that manual.

Space is Hard.

Yes, but these days there really seems to be the lack of desire to do
something about it.

Maybe that is because NASA could well be a jobs program and that
congress dictates the rules, but the past 30 years of human
spaceflight can only be seen as depressing.

Back in 1970 many people could certainly believe that they would soon
be off to Mars, where certainly NASA had the ambition for it.

And I don't know what really happened, maybe a whole series of really
bad ideas, but in the end we did not get the thousands of shuttle
flights and dozens of space stations that NASA predicted.

So I can only hope that one day NASA gets back the balls to design a
550 ton launcher, when that is the kind of attitude that can colonize
this solar system.

These days though NASA is all "high tech", which costs them far more
then getting their parts from a shipyard.

It's not as hard as some think and NASA sometimes makes it
out to be, but it is a hard, complex, highly technical,
highly political process.

And to begin with there is the desire and the determination, which is
the one thing that is lacking that makes all these other things
happen.

Even true experts take decades to learn it.

I can begin to see why.

If you care, and you're making
enough noise that you seem to, then you *really* need
to get off your ass and start learning.

Well I already know a vast amount, but this is kind of like all areas
of space at once. And rocket science has never really been an area
that has come up, when after all NASA has been using the Shuttle for
all of my life time.

Also I guess that people don't get technical on rockets much, when it
seems like the name, the cost and how many tons it can lift.

And to be honest I have not really got into NASA's pet Shuttle
replacement programmes either, except for that latest one with the
planned aerospike engines and the composite tank issue.

Make me wonder if that one would ever have worked out had they not
pulled the plug on it.

So you should think of me more as the person who knows about probes,
satellites, telescopes, cosmology and alien things like extra-solar
planets.

In other words all the things that your rockets launch.

The reason I am here I guess is that I am upset that NASA is not going
to the Moon in 2010 and Mars in 2020, which is what they were
certainly advertising a few years ago.

Cardman.

On Sat, 26 Jul 2003 07:17:29 +0100, Cardman
wrote:

On Sat, 26 Jul 2003 04:37:33 GMT, "Dave O'Neill" dave @ NOSPAM
atomicrazor . com wrote:

So? The same applies to the Earth.

Very nice, but the Moon is a pristine environment, which has preserved
many events for millions of years.

Snip

And I have just become aware of extra value with going to the Moon,
which is due to these Asteroid impacts.

Just one metal asteroid containing the likes of gold, cobalt, nickel,
and iron would be worth $20 trillion on the worlds markets. And there
are simply hundreds of these things on the Moon, which total in at
hundreds of trillions of dollars.

And of course there is water on the Moon if the science data is
correct, which is worth more than anything.

So if they don't want to go to the Moon and become as rich as
anything, then they are obviously crazy.

Also China will be on the Moon one day soon, where not only will they
steal your He3, but they will get all these valuable asteroids as
well.

And if the U.S allows this too happen, then China will become the sole
rich and powerful super power, while the U.S sinks into poverty.

Hell if I had the money to form my own space organization, then I
would be off to the Moon in no time to claim my fortune. Even have a
throne of diamonds and call myself the Moon King. ;-]

Cardman.

And of course there is water on the Moon if the science data is
correct, which is worth more than anything.


That is probably one of the more valuable items on the Moon

I am unclear how. Who, exactly, would you sell Moon water to? The
only place with customers has plenty of water of its own.

It's true that the presence of water would make colonization a bit
easier, but that doesn't make the water valuable in the commercial
sense.