[ExI] Recycling in space
spike66 at att.net
Tue Aug 23 13:38:22 UTC 2016
From: extropy-chat [mailto:extropy-chat-bounces at lists.extropy.org] On Behalf
Subject: [ExI] Recycling in space
>...It is a fairly old idea, but it is nice to see people working on
actually recycling empty upper stage Atlas rocket fuel tanks as space
Sometimes the future is pre-used.
Dr Anders Sandberg
Anders, back in the 80s, this was almost done. Plenty of us who are into
this sort of thing already knew that when a space shuttle goes into orbit,
it drops an external tank which is very nearly already to orbit speed. To
carry it on up there requires sacrificing about a third of the maximum
theoretical payload capability of an STS mission, but... that maximum
theoretical limit wasn't used anyway: it was too scary. Should anything go
even a little wrong on the way up on a max payload mission, they can find
themselves suddenly with no way to get to orbit, no way to get rid of the
payload, no way to turn about and return to the launch site, no place to
ditch and even if they did make the emergency landing site, the payload
would be too heavy to land; the hapless astronauts have about 20 minutes
regret ever having gotten mixed up with NASA, choose a religion and pray for
an afterlife, that sort of thing.
Consequently, few STS missions were anywhere near fully loaded. So... most
of those missions could have carried the external tank to orbit, at least a
low one, without sacrificing anything at all. When the tank arrives in
orbit, there is still both hydrogen and oxygen aboard for most missions.
They sometimes use up all the LOX, but always have some H2, since they
intentionally carry extra. At main engine cutoff, they pour left-over
hydrogen through the engine to cool off the hot bits, flush out any
remaining oxygen thus extending the life of the engines. A nice cool
hydrogen bath is so refreshing after hoisting a space plane to orbit.
We had a kind of a hobbyist group at Lockheed proposing uses for an empty
tank in orbit (kicked around ideas after work, no fulltime charge numbers
for that kind of work. I wrote a couple proposals.) There was the problem
with that notion however. If they drop the tank in the usual way, they know
where it will land: out in the Indian Ocean. But if they carry it to orbit,
there are three choices: carry enough propellant for a periodic reboost and
keep it there, bring along the tank's own guidance system and motor to
de-orbit in a controlled fashion, or just let nature take its course and
hope wherever it comes down it doesn't fall in some commie's backyard and
trigger world war 3.
The first two options were really expensive, the third offered about an
even-money chance it would drop in the vast Pacific and no one would notice;
very little chance of actually smiting some hapless prole. But NASA didn't
like the risk and the bad publicity of it all, and wanted a really good
justification to even do it once, just to show it could be done. So our
group worked to find one.
If you look at artist renderings of 80s versions of the space station,
sometimes they will show STS external tanks nearby, or some might even show
them attached to the station. One proposed piece of hardware was a
spherical module with a means of attaching an STS tank. That notion got as
far as a NASA funded engineering proposal team to get the design concept as
far as preliminary design review (PDR) stage. A PDR requires enough detail
to know dimensions, weight, all the details down to perhaps 10% uncertainty
or closer on weight. I was lucky enough to work part time on that in 1989.
We had a proposed design at the end of one of the space station modules
which would attach a tank specially fitted with an access hatch. It was a
really cool little project, very focused, small team.
In that year the commies complied with Mr. Reagan's dramatic suggestion and
tore down the Berlin wall. Both countries started acting like they didn't
want to fight a nuclear war at all. That whole nuclear winter thing made
plenty of us nervous. I am much more a summer fan, and the radioactive
fallout is such a bother. Less publicity was given to a reduction in
nuclear development which came along with Gorby's peaceful gesture, which
freed up a bunch of nuclear engineers and scientists. We didn't want all
those unemployed taxi-driving Dr. Nukeskys resettling in Iran, so a plan was
hatched to make space scientists out of them.
The outcome was the space station's orbit was raised to a higher inclination
which made it to where the STS could carry less payload, but would allow the
commies to get there from Baikonour. Both countries paid more for payload,
as did the Europeans way up there in that northerly inclination, so it was a
severe compromise, but weighed against sweeping up radioactive dust off the
driveway before work every day, we supposed it was acceptable. The attempt
to make rocket scientists out of nuclear scientists mostly failed, for
although there may be a few vague similarities between the two disciplines,
such as both hire lots of geeks, they are dissimilar enough to be generally
unsuitable for cross-pollination. The Dr. Nukeskys made their way to Iran
and Iraq anyway, but we converted to what then became the international
The Germans and the Japanese reconfigured their modules by combining and
shortening them, then requested that if others did likewise, that they fit
their module end to end with either another module or our external tank
attachment facility. We didn't like it: when Germans and Japanese work
together, bad things happen. The Ruskies were going to build a module (can
you imagine?) and make a way for their capsules to dock, meaning we had to
convert our good old American measurement system from furlongs and rods to
meters with all those scary confusing prefixes such as "centi" and "milli"
and "kilo" based on conversion factors like 10 and 1000 rather than the
usual 2 and the intuitive American 17.3 as one naturally uses when
converting from hogsheads per fortnight to Kensington cubits per square
The end result was a redesign of the station known as the Price-Fischer
configuration, often derisively called the Fisher-Price configuration, to
call attention to the fact that the station was so downscaled as to no
longer be a useful research facility, with most of the science experiments
canceled. The Fisher-Price International station was little more than just
an expensive toy.
Plans to haul an external tank were abandoned, our tank attachment module
project was cancelled before we even got to pitch it at PDR, a critical
feature of the program was cancelled: in the Price Fischer design, the
International space station was closed-ended. Most space station engineers
were told to run along and play elsewhere, at which time (paradoxically)
plenty of us went from NASA work to defense-related stuff. I went into
electronics manufacturing for a while, which was educational but far outside
my expertise, then went into a plowshares group where we were trying to find
logical uses for retired military space hardware which was available to us
for a nickel on the dollar down to as little as free, if we could figure out
something fun to do with it. We wrote proposals until our pencils wore out,
never did come up with economical and peaceful ways to repurpose stuff
originally designed to destroy the world.
Previously the station was required to be open-ended, so that excess
available space shuttle payload capacity could be used to take stuff up
there and park it at the station, so that we could accumulate materials at
the station for later missions which hadn't even yet been dreamed up. That
was all gone. The new station was closed-ended, sneaky commies floating
around all over the place inside, and nowhere to park an external tank.
Gone. All that cool space stuff sacrificed, all just to save a few hundred
billion dollars and help prevent one little nuclear holocaust.
Anders, that's a geek's eye view of tanks in space.
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