Space Forum / Shuttle / February 2008

Pepto Bismol would solve this problem :-)

Wishful thinking.

This might help you understand what your seeing. Turn off the water to your
house and drain some of the water out of the pipes. Turn it back on and let
it pressurize. Pick a faucet that wasn't used to drain the pipes, one that
still has water in the line next to the faucet. Turn on the water and
watch. You'll notice a normal stream of water, pay attention to what
happens when the 60 psi air hits the faucet.

http://www.space-multimedia.nl.eu.org/index.php?option=com_content&task=view&id=
3298&Itemid=2
3:55 to 4:15 is the best section to watch

This is essentially what is going on with the venting of the tank. Gaseous
hydrogen or mixed gas/liquid is small spurts as the pressure relief valve
opens and closes and the liquid hydrogen begins to move towards the exit.
Then, a nice steady stream of liquid comes out, a burst of gas, then more
liquid. Long skinny stream of liquid.

Notice the cool shockwave pattern (if you can call it that), as the flow
transitions from liquid to gas. It's the "<" shaped pattern moving to the
right as the much higher velocity gas impacts the slower steam of liquid,
just like your faucet and all the spray when it spurts air.

The faucet is a good analogy, another might be a hose with a hand valve on
the end. Shoot a stream of water, the cut it off. Watch as the tail end of
the water as it flys away. This can also be seen in the video, a nice
stream of liquid hydrogen flying away as the pressure relief valve shuts.
The tail end of the liquid gives a really good idea as to the velocity of
the stream of liquid. Of course the gas is much faster.

BTW, they had a nominal MECO the level of the Hydrogen never got below the
ECO sensors in the tank, there was plenty of fuel left in the tank. As, you
can clearly see the liquid vented out of the tank.

Looks like the liquid might travel quite a distance before evaporating.

Good thing the Orbiter wasn't in this stream of liquid hydrogen. Luckier
than Monty's Dog, I'd say.

Forgetting all other realities for a minute, would it be possible for
the shuttle to detach from ET, roll over, and then use the arm to
grapple the tank (assuming grapple fixture on ET) and then tow it to the
ISS that way ?

Would the arm be strong enough to hold the ET during OMS burn ?

As you can see, Craig Fink is one of our village idiots.  I killfiled him
for this very reason.  I don't know why, but he keeps going on and on how
*he* could make money by forcing NASA to do his bidding.  Evil genius
wannabe, I guess.

Jeff

Fifty passenger, i can imagine that's true. Probably not the best use for an
alpha vehicle, but 25 with escape system in the payload bay might not be
bad.

To me the Shuttle is a fine alpha concept. One that NASA is abandoning for
the near futures (20-50 years), in favor of rebuilding an Apollo type
program. But, it's a great concept and has more capabilities that are being
lost than just carrying 50+ passengers. To me, it's more enjoyable to talk
about it as if it was your own vehicle, that NASA would actually privatize
the manned space program, at least the Launch/Landing portion. Something
the Russians have done to some extent. From a prospective of, if they
actually were sold on E-Bay, what would I do with my purchase to make it
profitable.

The other unique capability besides 50+ passengers, is the ability to bring
the same size payloads back.

Another is a standardized cargo mass/volume concept, it would be a
reasonable standard. Kind of like how containerized shipping has
revolutionized international trade.

NASA isn't going to build a beta Shuttle, privatization of NASA manned space
flight and the Shuttle would be a great step in the right direction. In the
private world, the Shuttle isn't really even near optimal for travel
between Earth and a Space Station/Motel/City. But it would be a reasonable
first step alpha, to follow on with a beta Shuttle in the Private world.

There are a lot of things that could be done to the alpha shuttle to make it
more profitable in the Private world. Things that would never get done in
the Public Funding world of NASA. The first being to treat the External
Tank as payload instead of trash. Essentially doubling the payload of each
flight. This change costs almost nothing for such a huge gain. Adding a
small gas/liquid separator and gaseous H2 O2 low pressure engine to the
intertank, and the residuals and unusable become usable, the ET is at the
space station with a full payload bay. The smaller the engine the better,
but it has to still be capable of completing the Rendezvous in a reasonable
time frame.

In a follow-on beta shuttle, replacing the RCS/OMS with gaseous H2/O2
engines would be great. Essentially turning all residual/unusable ascent
fuel/oxidizer into something useful.

Dreaming of how to modify a alpha Shuttle, leads to the next step, a better
beta Shuttle optimized to go to a Space Station/Hotel/City. Treating the
External Tank as payload helps build a Space Station, Hotel, City,
Manufacturing, Industry. A few million lbs of Aluminum in Orbit would be
quite valuable.

Once the ET is thought of as payload, then other modification to it become
more obvious. Things that don't cost much in terms of payload, but increase
it's usefulness. Obviously, this might include a larger access door in the
bottom of the ET. Maybe, even the whole docking adapter.

And now NASA wants to abandon the Space Station, in favor of a Moon
Base/Station.

I hope Congress is smart enough to figure out that it's the right time to
privatize LEO, the Shuttle and the Space Station. Giving the Shuttle an
extention in the hands of NASA would just be a waste of money. NASA should
sweeten the milk for manned space flight investment, encouraging Private
Enterprise, instead of souring it.

Maybe the Space Station will show up on E-Bay along with the Orbiters.

And, I still want my Free ET, preferably at the Station. NASA has never
embraced the spirit of Reagan's offer.

Ron Paul in 08! :-)