ET Apogee

Who Needs Fender? wrote:

bob haller wrote:

imagine what sort of structure could be in orbit if most of the ETs
had been assembled into a station

Interesting idea--I wonder if it would be possible to reach orbit with
the ET still attached (e.g. how much extra fuel would be required at
OMS-2)...

You could have a very massive structure up there by lashing several
together... now, how useful would it be based on the structure of the
ET... I guess it could be used as a storage facility... or refilled on
figure flights and used as an orbiting refueling station for later
deep-space missions...

Yeah, we would have a Space Station with two, three or four times the mass. Available volume to would be huge. Safety Factors on all the aluminum parts could meet civil engineering standards. Yeah, lots of excess aluminum would be available for lunar/mars exploration. Of course, this would have required the development and early launch of some spacebots to reprocess the aluminum into more useful Space Station structures. I can imagine the first spacebot developed would have be to simply cut most of the aluminum into wire for storage. Or, melt it into a great big raw materials blob. Reducing drag and stripping all the foam in a high drag orbit. I wonder if the foam would melt or sublime first in a vacuum? If it melts, it could be reused. If it sublimes, it could provide thrust.

I can imagine a fifth or sixth generation Space Station that might actually be built out of upper stages. The spacebots would be really busy keeping up with each launch.

Jeff Findley wrote:


A pipe dream ...

Pipe dreams of the past are the reality of today, without the dreamers we never would have traveled into space to begin with.

Craig writes:

Who Needs Fender? wrote:

bob haller wrote:

imagine what sort of structure could be in orbit if most of the ETs
had been assembled into a station

Interesting idea--I wonder if it would be possible to reach orbit with
the ET still attached (e.g. how much extra fuel would be required at
OMS-2)...

You could have a very massive structure up there by lashing several
together... now, how useful would it be based on the structure of the
ET... I guess it could be used as a storage facility... or refilled on
figure flights and used as an orbiting refueling station for later
deep-space missions...

Yeah, we would have a Space Station with two, three or four times the mass.

Is mass by itself a particularly interesting quality for a space
station to have, or should it be restricted to mass which provides some
useful purpose?


Available volume to would be huge.

Is volume by itself a particularly interesting quality for a
space station to have, or should it be restricted to volume which provides
some useful purpose?

Safety Factors on all the aluminum parts could meet civil engineering
standards.

What are the relevant civil engineering standards to be met, and
is ``meeting them'' compatible with the requirements of the external tank
to serve as an external tank?


Yeah, lots of excess aluminum would be available for lunar/mars
exploration.

Is there a shortage of available aluminum in the space program?


Of course, this would have required the development and early launch
of some spacebots to reprocess the aluminum into more useful Space
Station structures.

What sorts of human-performed work are necessary to turn aluminum
into useful space station structures presently, and how difficult would
it be to make automated, or at least tele-operated, all of those tasks?


I can imagine the first spacebot developed would have be to simply cut
most of the aluminum into wire for storage. Or, melt it into a great big
raw materials blob.

Is there a shortage of available wiring for the space program
presently?


Reducing drag and stripping all the foam in a high drag orbit.
I wonder if the foam would melt or sublime first in a vacuum?

What does the foam presently do? Why would it be expected to
change by having its drag reduced?


If it melts, it could be reused.

As what?


If it sublimes, it could provide thrust.

How much thrust, and what would be required to use it as a
directional thrust, and what would be the usability and cost penalties
of that adaptation?


I can imagine a fifth or sixth generation Space Station that might
actually be built out of upper stages.

What generation space station are we presently on?


The spacebots would be really
busy keeping up with each launch.

What is a likely launch rate for human-carrying space expeditions
for the coming five years? Ten? Twenty?

--
Joseph Nebus
------------------------------------------------------------------------------

Joseph Nebus wrote:

Craig writes:

Who Needs Fender? wrote:

bob haller wrote:

imagine what sort of structure could be in orbit if most of the ETs
had been assembled into a station

Interesting idea--I wonder if it would be possible to reach orbit
with the ET still attached (e.g. how much extra fuel would be
required at OMS-2)...

You could have a very massive structure up there by lashing several
together... now, how useful would it be based on the structure of
the
ET... I guess it could be used as a storage facility... or refilled
on figure flights and used as an orbiting refueling station for
later deep-space missions...

Yeah, we would have a Space Station with two, three or four times the
mass.

Is mass by itself a particularly interesting quality for a space
station to have, or should it be restricted to mass which provides
some useful purpose?

Yes, since the parts of space we travel in are void of mass, aluminum mass is particularly useful, probably reasonably transformed into all the purposeful things that make up the majority of the mass of a space station.

Available volume to would be huge.

Is volume by itself a particularly interesting quality for a
space station to have, or should it be restricted to volume which
provides some useful purpose?

Yes, the lack of mass in space, especially N2 and O2, is what makes space station volume interesting. Especially to humans that are living there. It is probably the most interesting quality of a space station, because it makes all the other interesting thing possible.

Safety Factors on all the aluminum parts could meet civil engineering
standards.

What are the relevant civil engineering standards to be met, and
is ``meeting them'' compatible with the requirements of the external
tank to serve as an external tank?

Safety Factor, huge instead of the bare minimum. The actual mass of a space station is unimportant if you have plenty of it. Something space and LEO in particular is void of.

Yeah, lots of excess aluminum would be available for lunar/mars
exploration.

Is there a shortage of available aluminum in the space program?

In Space?

Yes, there is an extreme shortage of available aluminum that is useful in LEO. And, no, there is a growing abundance of non-useful aluminum that would be classified as debris, something to be avoided for hundreds if not thousands of years.

Earth has plenty of mass, including aluminum.

Of course, this would have required the development and early launch
of some spacebots to reprocess the aluminum into more useful Space
Station structures.

What sorts of human-performed work are necessary to turn aluminum
into useful space station structures presently, and how difficult
would it be to make automated, or at least tele-operated, all of those
tasks?

I find that to be one of the interesting problems to be solved, probably most people don't. Imagine a tele-operator taking a vacation in the excess volume of the space station he or she built. Or, applying to become a spacebot repair-person.

I can imagine the first spacebot developed would have be to simply
cut
most of the aluminum into wire for storage. Or, melt it into a great
big raw materials blob.

Is there a shortage of available wiring for the space program
presently?

Not particularly the wire, but it might be one of the intermediate steps in reprocessing aluminum if used like welding wire in a 3-d parts printer. To give the tele-operator something to do. I'm not saying this is what the intermediate step will be, just something that a thin wall tank could easily be transformed into.

Reducing drag and stripping all the foam in a high drag orbit.
I wonder if the foam would melt or sublime first in a vacuum?

What does the foam presently do? Why would it be expected to
change by having its drag reduced?

In space, nothing. But, it is mass that could be made useful.

If it melts, it could be reused.

As what?

As something useful.

If it sublimes, it could provide thrust.

How much thrust, and what would be required to use it as a
directional thrust, and what would be the usability and cost penalties
of that adaptation?

An oven with a small hole called a throat leading to a nozzle. Penalty or asset, using valuable mass that happens to be in LEO for something useful. Currently the cost of the space station shedding non-useful mass is quite large. It's usally packed up and brought home with reaction mass that is brought up for just that purpose. And the Station is re-boosted with reaction mass that is brought up just for that purpose.Cost analysis TBD.

Reaction mass is something useful.

I can imagine a fifth or sixth generation Space Station that might
actually be built out of upper stages.

What generation space station are we presently on?

I was counting three, others might count differently.

The spacebots would be really
busy keeping up with each launch.

What is a likely launch rate for human-carrying space expeditions
for the coming five years? Ten? Twenty?

Fifty? or a Hundred?

If we continue on our current course, maybe the Earth will eventually have rings like Saturn. Aluminum rings instead of water. Once recycling becomes popular in LEO, you'll have to include all launches, not just the human-carrying kind. In a expendable to orbit space economy.

You sure had a lot of question marks? So, were do you see the future of human space exploration going?

Jeff Findley wrote:

It's far easier to launch modules fully outfitted than do the outfitting in
LEO. Look at the history of Skylab, and even ISS, and this becomes
abundantly clear.


While we may not be ready for this yet, isn't it conceivable that in the
future, we will be called upon to do more than just connecting cables
and not losing the screwdrivers when tightening a few bolts ?

Say they were to bring the ET to the station and berth it to nadir node1
or node2 (parralel to truss to give clearance for soyuz to dock).

Could they not then progressively wrap it in proper insulation (leave
foam there, but covered with micrometeorid insulation) ?

Outfitting the interior would be a challenge and keep people busy for a
few years. But the H2 lank woul provide for a nice gymnasium where they
could play 0g basketball for instance. They'd just have to ship the wood
slats for the flooring all round the station and place hoops at both
ends :-)

But I realise that outfitting the inside of an ET with racks, wiring etc
would be quite a bit of work.

BTW, what PSI ratings are those tanks ? Is 14.5 psi something that is
well within the capabilities of the tank ?

All of this is academic since the Shuttle progam is coming to an end
by around 2010 or 2011 depending on what the Obama adminstration
decides here. But more importantly, inflatable station modules, like
NASA's Transhab and the later Bigelow modules, provide all the
advantages of large volume and pre-outfitted on the ground, but can be
launched on relatively small, cheap rockets. So the whole ET station
thing is obsolete, and an orbital debris hazard waiting to happen.
-Mike