Skylab and Shuttle

I know that Skylab reentered due to significant solar activity heating the upper atmosphere, and I also know that non-human caused PODs are automatically categorized into ASB.

Instead of postulating a POD with the sun, I’m going to postulate a POD where the tele-operated retrieval system is launched on an unmanned rocket (such a mission was proposed and rejected ITTL), docks with skylab, and saves it, leaving it two years longer in orbit until Space Shuttle Columbia can show up. So, with skylab available as a shuttle destination early on (thus oblivating the need for billion dollar space station construction, which Congress was always willing to cut on), what POD does this have on U.S. space exploration? Would skylab form the “core” of Freedom-esque station? Would such a POD be early enough to leave some Apollo hardware to reuse as a “crew return vehicle” in emergencies (Apollo CSM launched in shuttle bay, docked with skylab as lifeboat)?

EDIT: how hard would it have been to change the atmosphere?
 
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Certainly Marshall (which had built the thing) wanted to make Skylab the core of a larger station, as here, for instance. The difficulty is that Skylab wasn't designed to be serviced in orbit (eg., the oxygen tank was about half full of trash by the end of the human missions, and could not be emptied); it had (even by 1980s standards) primitive onboard systems, particularly for computers and data-handling systems; and was in some respects incompatible with the Shuttle (eg., in air pressure).

Certainly Marshall had answers to all of these problems, but a lot of them relied on developing new hardware, like the Power Module to replace the damaged ATM and workshop solar cell arrays and the workshop's gyros, or a docking module to interface between the Shuttle and the workshop. If you're going to the trouble of developing that much hardware, why bother with the Skylab in the first place? Dropping Skylab altogether and simply putting together the hardware you already needed to develop in a station complex will probably not even increase the cost.

Where NASA erred wasn't so much in abandoning the decrepit and run-down Skylab, it was more in developing a successor (Freedom/ISS) which was excessively large and heavily overburdened with different tasks. A smaller station could easily have been completed much earlier, partially by simply being smaller (fewer construction flights), partially by being subject to fewer redesigns (cheaper). Of course, that might have led to issues when the Shuttle had issues, so one could plausibly say that OTL's path is somewhat close to optimal given a PoD after 1972, at least as far as sustaining an American presence in orbit is concerned.
 
Certainly Marshall had answers to all of these problems, but a lot of them relied on developing new hardware, like the Power Module to replace the damaged ATM and workshop solar cell arrays and the workshop's gyros, or a docking module to interface between the Shuttle and the workshop. If you're going to the trouble of developing that much hardware, why bother with the Skylab in the first place? Dropping Skylab altogether and simply putting together the hardware you already needed to develop in a station complex will probably not even increase the cost.

But at much lower usable space without Skylab. With Skylab, at least you had the pressure vessel, even if everything else would have to be replaced. Besides, it’s less about the large, out of date tank in orbit than the fact that there IS a large, out of date tank in orbit for the shuttle to go to, and that missions to launch space station hardware will be seen not as assembling a totally new station, but adding to one in orbit instead, which IMHO will be an easier sell to Congress. You know as much as I do that there were dozens of space station plans in the 70s and 80s that were lightweight and could have been built (a good example being the Science and Applications Manned Space Platform), sure, but never were, with plans instead focusing on unrealistic space refueling depots and orbital workshops.

Hell, Skylab expanded MIGHT even still be operating today.
 
But at much lower usable space without Skylab. With Skylab, at least you had the pressure vessel, even if everything else would have to be replaced.

But the pressure vessel is one of the cheapest parts of the station altogether. After all, it's just a metal tank (or of course inflatable, but that hadn't been developed in the '80s), and one that's only exposed to one atmosphere of differential pressure (compare not just submarines but many storage tanks as well). It's much more expensive to fit it out with all the other systems needed for space operations.

And the point I was trying to make was that it would be almost impossible to replace all those other systems. Look at the trouble Russia had with Mir; sure, a lot of that was because they had no money, but a lot was just because by the end all the modules were ten to fifteen years old and were worn out. That will be much more so for Skylab, which, unlike Mir, wasn't really designed for on-orbit resupply and servicing and will have been allowed to deteriorate unattended for some time. Of course Salyut 7 and Mir itself were unattended for periods too, but not as long as Skylab.

Besides, it’s less about the large, out of date tank in orbit than the fact that there IS a large, out of date tank in orbit for the shuttle to go to, and that missions to launch space station hardware will be seen not as assembling a totally new station, but adding to one in orbit instead, which IMHO will be an easier sell to Congress. You know as much as I do that there were dozens of space station plans in the 70s and 80s that were lightweight and could have been built (a good example being the Science and Applications Manned Space Platform), sure, but never were, with plans instead focusing on unrealistic space refueling depots and orbital workshops.

Space station per se wasn't too hard to sell to Congress, though; if you look at it, a good comparison might be with what you might broadly label Obama's space plans, particularly the large funding initially earmarked by the administration for COTS/CRS/CCiCAP/etc. programs, which was later reduced by Congress. Although Congress was somewhat reluctant to fund station, and clearly it had a near-death experience in 1991, it was relatively easy to convince them in the beginning that it was a worthwhile program, when they were essentially expecting NASA to use one of the lightweight concepts.

NASA ignoring the multitude of lightweight station programs that it had developed is more a case of a bad internal culture and bad internal politics. For the first, the never-eradicated "Kennedy fixation" was particularly bad at this point (probably unsurprisingly, since a lot of senior people at this point would have been junior Apollo people!), manifesting itself as expecting a larger program out of Reagan than he actually desired and therefore a desire to build a station which could support said larger program (read: SEI). For the second, the conflict between Marshall and Johnson for dominating the HSF program as Portree describes, which Johnson more or less won. Johnson had wanted a larger station all along (which is funny because of course the arch-Marshallite von Braun was a big station proponent). A timeline where Marshall gains enough added clout to save Skylab is a timeline where Marshall probably has enough clout to push through some of its incremental Shuttle upgrade programs that are also on Portree's site, which might then lead to a more lightweight station.

Hell, Skylab expanded MIGHT even still be operating today.

It would be 40 years old. That's a LONG time to ask ANYTHING to be useful in the near-Earth environment (or really, anywhere in space...and many places on Earth). I am...skeptical, to say the least.
 
on Skylab internal air pressure
it was build original as fuel tank holding on maximum pressure of 2.4 atm
the low pressure atmosphere was because use of Apollo Hardware.
under shuttle reuse, it could operate with normal air pressure.

on Skylab hardware Live time:
the station was build in 1970, launch 14 may 1973
function 513 day (168 day with crews) and "hibernate" on 8 February 1974.
"hibernate" i mean shotdown of most electrical systems, except flight computer gyro, RCS.
air pressure in station went to near vacuum


If the Space Shuttle dock on Skylab in 1981
they have a over one year used Station, who was sleeping for seven years.
with repairs and update on electrical systems, Skylab could work 14 to 20 years
that would be in 1995-2000
 
on Skylab internal air pressure
it was build original as fuel tank holding on maximum pressure of 2.4 atm
the low pressure atmosphere was because use of Apollo Hardware.
under shuttle reuse, it could operate with normal air pressure.

Yeah, the OWS. The problem would be the MDA and the other supplementary modules, which were not designed to work under 1 atm pressure, unfortunately.
 
The better solution

...is the one suggested in e of pi's and truth is life's current Timeline, Eyes Turned Skywards. To wit: Not Skylab, but the never used Skylab B, now sitting on display in the National Air and Space Museum. It could have been modified to permit more living room, updated electronics, power and habitation systems, and to allow easier modular expansion and resupply.

Of course, the difficulty in our TL was money - always money. Not just money to modify and keep ready the Skylab B, but also the launch vehicle. There were, of course, two unused Saturn V launchers, the only vehicles capable of lofting something so large. But keeping and launching one of them would have cost money, too. But in either case, not so much that NASA couldn't have tried harder to find a way to keep either as options. God knows, it would have been vastly cheaper than the Freedom humunculous that NASA kept tinkering with throughout the 80's.

In this respect, Truth is Life is dead on: "A smaller station could easily have been completed much earlier, partially by simply being smaller (fewer construction flights), partially by being subject to fewer redesigns (cheaper). Of course, that might have led to issues when the Shuttle had issues." But NASA was far too ambitious for its own good. Had they spent the minimal funds to keep Skylab B and a Saturn V in maintained storage, they would have had a far easier time getting the funding in Reagan's first term to use both, than the ridiculously unrealistic Freedom plans that were always to prove stillborn. In a way, it was of a piece with the entire Shuttle era: NASA too readily aimed at vastly ambitious, clean sheet systems that proved unaffordable and too risky rather than try to take more modest, step-by-step progressions of existing hardware. It was a bad habit formed by the open piggy bank funding and political support of the mid-1960's, as those junior Apollo people Truth Is Life alludes to rose up to the ranks of power at Johnson.

Using Skylab A would have been better than nothing, but as the reuse plan that was linked indicates, the possibilities there were rather limited. Skylab just wasn't designed for long-term use.
 
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Yeah, the OWS. The problem would be the MDA and the other supplementary modules, which were not designed to work under 1 atm pressure, unfortunately.

Damned! i forgot that detail, thx truth is life for info

Air pressure in Skylab is 6.2 psia vr shuttle 14.4 psia
while MDA/AM could support maximum air pressure of 8.7 Psia
the Windows in Skylab hold maximum pressure of 7.5 Psia

The Mcdonnell/Douglas study NAS8-32917 (19790011998.pdf at NTRS)
has two proposals
one: stay in Shuttle Airlock for 3 hours. here the crew breath for 2 hours pure oxygen and move from Orbiter to Skylab
two: raise the Skylab Air pressure to 7.35~7.5 psia, while Orbiter stay on 14.4 psia

Marshall center study MCR-78-855 (19790075817.pdf at NTRS)
proposed Orbiter pressure down to 12.6 Psia and Skylab rise to 6.3 Psia
 
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