Using The Shuttles External Fuel Tank In Our Return to The Moon and Our

On Jan 9, 2004, at 2:03 PM, Alex Michael Bonnici wrote:

> I am left wondering why NASA never seriously
> considered the various proposals to use the shuttle's external tank
> (ET)
> as the building blocks in developing a permanent space station and
> cyclic spacecraft that would take us to the Moon, Mars, and perhaps to
> the Asteroid Belt, and Outer Solar System. Why wasn't this idea ever
> really given the attention it deserves?

I'm not sure of the exact level of attention it received, and its an
interesting idea. NASA did make the tank available, for free, for
anyone who could show they wouldn't let it fall down at some random
location. There were no takers.

There are problems with using the tank. To do anything useful the tank
will have to be outfitted in orbit. There is a hatch on the bottom,
it's not very big but probably adequate to get inside and do stuff.
However, even with the hatch outfitting in orbit will be difficult.
Consider the difference between outfitting the interior of a submarine
in port on a dry dock, and doing the same work on the sub when it's at
the bottom of the ocean and flooded. This will give you a good idea of
the problems. Not impossible, but difficult and expensive.

There was a proposal to put a module on the aft end of the tank. This
could be outfitted on the ground. Unfortunately, filling the space at
the aft end of the tank between the SRBs created serious aerodynamic
problems in simulation and the idea was dropped.

One could think about using the left-over hydrogen and oxygen in the
tank, but the system wasn't designed for on-orbit fluid transfer and no
one has much experience in this area (there was one shuttle experiment
many years ago, but that's it). On-orbit fluid transfer can't use
gravity or air-pressure so you need some sort of gas pressurization
system to get any movement.

I like the idea of using the tank for a sports facility, but an
inflatable might actually work better.

The International Space Station's (ISS) most important legacy may be
jump-starting space tourism. Consider: the first space tourist, Dennis
Tito, was supposed to go to the Soviet era Mir space station. Under
pressure from NASA, Russia de-orbited the Mir which resulted in Mr.
Tito going to the ISS instead. Now the Mir was a terrific space
station, but by the time of Tito's trip it was also old, smelly,
crowded and probably not all that nice. The ISS was brand new, shiny,
much more roomy, etc. Mr. Tito came back to Earth with glowing accounts
of how great space is. Would his experience have been as good on Mir?

Al Globus
CSC at NASA Ames Research Center
http://www.nas.nasa.gov/~globus/home.html

Views expressed in this email are only my opinions and are not the
position of any organization I'm familiar with.