Some Questions

> 1. What is wrong with the shuttle? I understand it is expensive
to run
> but why is it expensive? Can the problems all be fixed with a
mark II
> version?

hooboy, where to start...
First of all, the shuttle is a reusable spacecraft. That means that
it has maintenance costs which expendable vehicles do not.

Second, the shuttle has wings. These are used to provide a little
steerability in the last few seconds of the flight. The inclusion
of wings leads to a cascade of problems. They cause the design of
the orbiter body to be symmetrical in only one direction, instead of
radially symmetric like the Mercury, Gemini, apollo, and various
Russian and now Chinese capsules; this means that the heat shield
tiles are individually made, and each one is unique. Since they are
re-used, they have to be (expensively) scanned for wear, selectively
removed and then a unique replacement for damaged tiles must be put
in place - all without affecting the integrity of neighboring
tiles. This adds hugely to the maintenance budget.

Third, the shuttle has wheel wells on the bottom, which are natural
weak areas in the heat shield; that is just asking for trouble.

Fourth, the winged shape causes incredible heat along the leading
edges of the wings, particularly during reentry - forcing the
inclusion of brittle carbon-carbon panels on the leading edge.

Fifth, an offshoot of the "reusable" idea is that the engines must
be reused. This forces the side-by-side configuration of orbiter
and fuel tank. If the engines were not reused, they could be placed
on the bottom of the fuel tank and the orbiter placed on top: a much
more survivable configuration in the event of a catastrophic
breakdown during launch. The early American manned rockets and the
manned Russian and Chinese rockets all carry a small solid-fuel
rocket atop the crew compartment. In the event of a launch
catastrophe, the solid rocket fires, carrying the crew capsule clear
of the exploding rocket below. In a shuttle liftoff accident,
survival is not an option.

Sixth, because the shuttle is controlled by a pilot for the last few
seconds before landing,he needs to be able to see what he is doing,
so he needs to be facing forwards during the landing, This also
means that he (and everyone else in the shuttle) with the gee forces
pressing them into their seats during liftoff but *pulling them out
of their seats and against their seatbelts* during reentry.

Seventh, the wings represent an enormous amount of deadweight that
is never used in space. This deadweight, coupled with the side-by-
side configuration, increases drag and fuel requirements. It also
means that a relatively cheap fuel like kerosene can't be used, only
the much more dangerous and expensive liquid Hydrogen.

As to _why_ the space shuttle has wings, the only conclusion I can
see is that "flying a spaceplane is sexy".

>
> 2. I heard that NASA abandoned the fuel tank based space
station idea
> because
> the tanks contain a toxin, I believe it was benzine. Is this true?
> Can this be cleaned from an orbiting tank? Can the engines be
designed
> to work without
> it? Is it all just bullshit?

The tanks can be easily cleaned by simply opening up some access
hatches; the shuttle system regularly vents the LOX tank after
separation to send the external tank tumbling. Besides this vent,
there is a 3 foot hatch at the zenith of the oxygen tank and two
three-foot hatches at the nadir of the hydrogen tank. There are
also three foot hatches into the two tanks accessible from the
intertank, but one wouldn't want to open both at the same time when
they still have residual propellant inside.

NASA has been inexplicably wasting ETs for decades. During a
launch, the shuttle system gets to 99% of orbital velocity before
*slowing down* then releasing the ET and venting its oxygen tank.
Then the shuttle uses its on-board fuel to make it the rest of the
way to orbit.

If instead they used the simpler flight program and carried the ET
until it was empty, then released it and went on their way with the
on-board tanks, the ET would be in an elliptical orbit that would
decay within about two weeks. Where it would land is anyone's
guess. If it wasn't made to tumble before entering the atmosphere,
it would come down in one piece, 30000 kg of Aluminum/Lithium alloy,
a minimum of 10000 kg of Oxygen, and a minimum of 1000 kg of
Hydrogen. kerboom. Hope it doesn't land on Beijing.

So NASA claimed that they discarded and destroyed the ETs as a
safety issue. They ignored the designs for an Aft Cargo Carrier the
engineers of the Michoud facility (the place that makes the tanks)
came up with in the early 70's, claiming that the necessary change
to the flight software posed an unacceptable risk. Finally NASA was
forced by president Reagan to *give* used ETs in orbit to anyone who
could safely salvage tehm. NASA came up with four hard-and-fast
rules about possible ET salvage:

1) orbit: the elliptical orbit the ET would have at separation would
need to be circularized and maintained.

2) SOFI: the spray-on foam insulation on the tank exterior would
outgass (slowly be decomosed by and sucked into the vacuum) if left
alone, so it must be either stripped or covered. The debris field
produced by an outgassing ET would be enormous and create a
persistent danger to anything being launched or already in a lower
orbit.

3) residuals: The ET would have about 10000kg of Oxygen and 1000kg
of Hydrogen left, both in the tanks themselves as well as in the 17
inch feed lines and 4 inch filler lines. These either must be
vented or kept cool; can't have the Hydrogen tank getting too hot
and rupturing, scattering orbiting shrapnel everywhere.

4) control: the ET salvage must be equipped with a power supply,
heaters and heat dissipation hardware, a computer, antennae for at
least two communications bands, and maneuvering thrusters; in short,
the ET must be made a complete, controlled satellite.

In addition, NASA will not consider any salvage method which
requires EVA or the time of one of the astronauts aboard the
shuttle. Nor will they consider any proposal which requires a major
change in the flight plan; getting them to bring an ET all the way
to orbit is about as far as they would be willing to go.

So far, nobody has come up with a proposal which could feasibly
salvage an ET according to NASA's criteria. Anybody who wants to do
so had better hurry.

> 6. Everything I have read lately including The High Frontier 3rd
> edition from Apogee
> Book seems to indicate NASA is a fossilized dinosaur like old IBM
was to
> the computer
> industry back in the 60s and 70s. Shouldn't space travel
advocates try
> to
> pull NASA down?

That is one alternative. Another is to simply go around them, and
make them irrelevant (or wake them up like Apple did to IBM).

> Don't just point out what NASA does wrong but what NASA could be
doing
> right.
> Pointing out to the taxpayers how NASA seems to abandon promising
> technologies like
> the Delta Clipper in favor of the shuttle which is old and needs
to be
> replaced.
> Pointing out how NASA's plans don't include civilian activities in
> space, neither industrial or tourist, even if such would be a good
idea.
> Pointing out that,
> if the shuttle tanks are safe or can be made safe, that it cost no
extra
> to bring them in
> orbit and that they can be made into cheap space stations and
hotels.

I wouldn't use the present shuttle system to put a tank-based space
station in orbit. Instead, launch a fueled tank belly-to-belly with
another "dry" tank. The dry tank would only weigh 66000 lbs,
compared to orbiter's 250000 pounds + payload, so it could
conceivably contain 100 tons of aft cargo carrier and engines,
cargo, air, etc. You would be getting two tanks into orbit for the
price of one.

> Why isn't NASA being crushed for holding the dream back? For
holding
> the people from space?
> Why isn't everyone involved in any way with space colonization
trying
> everything
> thay can to destroy NASA and make a new agency that can do a
better job?
>

A new agency isn't the answer, it's a repeat of the same thing with
the same people.

What is needed is a true space marketplace, where competition forces
innovation and drives costs down. To do that, people have to
believe that they can make money on space ventures. Currently
nobody can, with NASA in the market driving up the bidding with
their near-infinitely deep pockets and mountains of government red
tape for any launch company to wallow through.

Probably the best thing the US government could do for space
exploration is get the hell outa the way.

> I hope this generates discussion and ideas.

I hope so too.

> Thank you for reading this.
> Darkstar

Keep the questions coming :D

Ed