Boldly Going: A History of an American Space Station

[RanulfC]

On the one hand, I am glad that Enterprise will have a more active role ITTL, rather than as a museum piece. On the other, it hurts a little to see her mutilated so.

And on the gripping hand once you have a non-American astronaut aboard it is a step closer to Roddenberry's 'vison' of "The Enterprise" being EARTH's first united space effort

Randy

 

[Athelstane]

And a question on the 'difficulty' of wet-lab operations; On the converse side I've only found mostly positive comments directed at operations of a 'wet-lab' design from the aspect of astronaut testing. Both the initial S-IVB wet-lab experiments, (in fact WvB climbed into a suit and did neutral buoyancy testing himself in September of 1968 with his only comment being the need for more installed hand-holds, see: https://history.nasa.gov/SP-4011/part2b.htm, https://history.nasa.gov/SP-4011.pdf) and later during testing of the Shuttle External Tank. Most of the complaints I've see were for the early MORL testing and specifically with the un-modified Mercury suits before they knew for sure about the cooling problems.

Well....no offense to the great von Braun, but color me deeply, profoundly skeptical.

There's a reason - multiple reasons - the Apollo Apolications staff abandoned a wet workshop design for Skylab for a dry one at the very first opportunity. As Robert Thompson, the NASA engineer who managed the Apollo Applications Program from JSC acidly put it, a wet workshop "was just about the dumbest idea I've ever heard. And I've heard a lot of dumb ideas."

 

[groundhogday666]

Folks,

How about the Aft Cargo Carrier ? https://webcache.googleusercontent....-1982/+&cd=1&hl=fr&ct=clnk&gl=fr&client=opera

A combination of the ACC, wet workshop E.T, and Spacelab modules - plus the transformed Shuttle Orbiter... !

 

[RanulfC]

However, as work began, NASA was about to begin relearning old lessons from Skylab and the orbital workshop. The concept of a “simple” conversion of hardware in space was rarely as simple in practice as it was in bullet points on a viewgraph slide…

Or the soon to be available Power-Point or frankly ANY "this will be easy/simple" plan on contact with that great denier called "reality"

Well....no offense to the great von Braun, but color me deeply, profoundly skeptical.

There's a reason - multiple reasons - the Apollo Applications staff abandoned a wet workshop design for Skylab for a dry one at the very first opportunity. As Robert Thompson, the NASA engineer who managed the Apollo Applications Program from JSC acidly put it, a wet workshop "was just about the dumbest idea I've ever heard. And I've heard a lot of dumb ideas."

And no offense but it isn't all that 'telling' that someone from JSC didn't like the wet-workshop idea as they historically (and as an institution) never liked the concept. Again the astronauts who actually worked on the concepts had no issues while the engineers, (who did not) didn't should actually be a bit telling If you have a choice then dry-lab is a better solution but (and specifically in this case) if you don't or you have that volume available for 'use' then a wet-lab offers you additional volume for little effort. And I'll also note that your own source notes it was FAR from the 'first opportunity' they had to move from a wet to a dry lab design. The 'initial' design was either "Apollo X" or a similar Saturn-1B launched "Lunar Adapter Module" station but they wanted more 'room' initially hence the move to using the 'wet-lab' hydrogen tank.

Keep in mind that until AFTER the Apollo 11 landing this was all based on the idea there would be NO Saturn V's available unless Congress authorized a second buy which wasn't looking likely. So they assumed they would have to use a Saturn-1B which wasn't going to be capable of launching a dry lab the size they wanted. (I don't really know why they 'quote' Thompson as telling Ars a "few years ago" as he's been saying pretty much the same thing since the first time an ET space station was proposed. Again such concepts were never supported by JSC as they wanted "only" dry and purpose built space station modules)

Folks,

How about the Aft Cargo Carrier ? https://webcache.googleusercontent....-1982/+&cd=1&hl=fr&ct=clnk&gl=fr&client=opera

A combination of the ACC, wet workshop E.T, and Spacelab modules - plus the transformed Shuttle Orbiter... !

ACC will take time to develop so I don't suspect that will get done in time. While it stated they are looking at the MSFC 'Power Module' I note the illustrations also show the 'Power Wing' concept in a few, (placing solar 'wings' in wing-root mounts on the orbiter) which I'm wondering if that would evoke 'memories' of Skylab's solar wing issues? At least with the bay mounted module you're fairly sure nothing deploys till you hit orbit

Randy

 

[marathag]

On the one hand, I am glad that Enterprise will have a more active role ITTL, rather than as a museum piece. On the other, it hurts a little to see her mutilated so.

Mutated like Jeff Goldberg in _The Fly_, the Brundlefly was just getting better.

 

[Athelstane]

And no offense but it isn't all that 'telling' that someone from JSC didn't like the wet-workshop idea as they historically (and as an institution) never liked the concept.

It may not be telling, but that doesn't mean they weren't right - because they were!

In fairness, however, I can't say that without making an important distinction between the particular context of the rightness of a wet workshop for Skylab in 1969-74, and the general question of their rightness in any space architecture. On the former, it really *is* hard to fault the skepticism of JSC engineers like Thompson: The record for continuous human presence in space in the summer of 1969 was about two weeks (and in volumetrically severely confined space), and NASA's experience of human activity in microgravity was thus severely limited. And now you're going to task these men with constructing a habitat mostly from scratch in orbit? Even setting aside the difficulties therein (however nonchalant the Apollo astronaut corps might be about it), Skylab would only offer limited time on orbit - all that was planned, if all went according to plan, was about 4-6 months total of mission time for three 3-man crews. Every minute spent installing deck grates or plumbing or toilets (at least they would be spared fuel contamination cleanup launching it on a Saturn V, at any rate) was a minute not spent on science or technical tasks - and the Skylab astronauts would have had to spend a lot of minutes doing all the installing. Outfit the lab dirtside and you don't have to make that tradeoff. The 1969 decision to make Skylab a dry workshop was a no-brainer. Even von Braun seemed to appreciate that.

The general question of wet workshops has more room to make positive arguments. It's just not all *that* much more room. As a hack to get yourself extra pressurized volume in space, it can work, but it's not a terribly good hack. You either end up with a rocket stage that makes for a poor habitat, or a habitat that makes for a poor stage, or worst of all, a piece of hardware so compromised that it's not really good at either role. A wet-lab in the right circumstances may well offer you additional volume for little effort, as you put it, but it's also going to be of similarly little utility, too.

In saying all that I prescind from any criticism of the timeline, because I think e of pi and Timothy have (as always) done their homework and presented a highly plausible (and enjoyable, for me) scenario of a could-have-been. It's not even that harsh of a criticism of the Reagan Administration decision makers here, because what they're getting is a relatively quick hack that will get them the space Cold War PR win they want - an American space station with a f***ton of pressurized space in relatively short time. Now, I don't think it will be a terribly *useful* station, or at least, not the "wet" component at any rate (and I expect a lot of teething problems, to boot) beyond possibly playing zero-g lacrosse . . . but then again, an awful lot of those pre-ISS Shuttle missions really weren't all that useful, either, as a justification for the dollars spent (and risks run). At least now they have a permanent platform for the shuttles to go to, at least as lifeboat option if nothing else . . . certainly, at least, until NASA can come up with a plan and the funding to build a from-scratch station.

Likewise, in saying this, I also prescind from any blanket endorsement of JSC on every space station architecture debate in that era, not least because as regards the best way forward for the Shuttle program in its first years, I think MSFC had the better of the argument. But that has largely to do with MSFC having a much more realistic appreciation of the political realities facing NASA's HSF program than JSC's leadership did.

Again the astronauts who actually worked on the concepts had no issues while the engineers, (who did not) didn't should actually be a bit telling

In a choice between engineers and astronauts on a question of, well, engineering, I think any sensible conclusion is almost always going to be on the side of the engineers! The engineers aren't fighting for mission assignments, for one thing. @groundhogday666's post up above gives us a timely case in point in this regard, alas.

 

[RanulfC]

It may not be telling, but that doesn't mean they weren't right - because they were!

Arguable as we both do below but...

In fairness, however, I can't say that without making an important distinction between the particular context of the rightness of a wet workshop for Skylab in 1969-74, and the general question of their rightness in any space architecture.

Context IS important of course but in that context the general question was initially the same; How do we get a 'space-station' on-orbit as soon as possible? And they came up with the same answers they had been since the idea of space flight had first cropped up. About a dozen with "using-your-ride-as-a-Space-Station" being one of them. (Speaking of engineers while we're at it )

On the former, it really *is* hard to fault the skepticism of JSC engineers like Thompson: The record for continuous human presence in space in the summer of 1969 was about two weeks (and in volumetrically severely confined space), and NASA's experience of human activity in microgravity was thus severely limited. And now you're going to task these men with constructing a habitat mostly from scratch in orbit? Even setting aside the difficulties therein (however nonchalant the Apollo astronaut corps might be about it), Skylab would only offer limited time on orbit - all that was planned, if all went according to plan, was about 4-6 months total of mission time for three 3-man crews. Every minute spent installing deck grates or plumbing or toilets (at least they would be spared fuel contamination cleanup launching it on a Saturn V, at any rate) was a minute not spent on science or technical tasks - and the Skylab astronauts would have had to spend a lot of minutes doing all the installing. Outfit the lab dirtside and you don't have to make that tradeoff. The 1969 decision to make Skylab a dry workshop was a no-brainer. Even von Braun seemed to appreciate that.

While those are minutes those astronauts are NOT going to be conducting science or technical tasks that's not a very good argument since it is likely tasks that are going to have much BIGGER relevance down the road if you plan on having any on-orbit work or assembly planned down the road. Note that JSC never DID have such plans whereas places like MSFC and Langley DID have such plans which is where the interest came from. JSC always planned as few orbital operations or EVA's as possible by design because, (as you note even though not directly) they didn't 'trust' human activity in or outside of a spacecraft. (Despite being the "Manned" Space Flight center) While granting there was no way of knowing it prior to Skylab's launch they in fact DID spend an inordinate amount of time 'fixing' Skylab anyway which was invaluable lessons and learning that would not have happened had things gone as planned. (And even THEN NASA faced a revolt due to the their un-reasonable work schedules)

The thing was though is that the "wet-workshop" WAS supposed to be a short-duration station and that was in fact a good thing when it was proposed because it was also part of the plan to have multiple 'wet' workshops as a means to have a broader and more economical station program. Skylab by design and motivation was always going to be essentially a 'one-shot' deal.

The general question of wet workshops has more room to make positive arguments. It's just not all *that* much more room. As a hack to get yourself extra pressurized volume in space, it can work, but it's not a terribly good hack. You either end up with a rocket stage that makes for a poor habitat, or a habitat that makes for a poor stage, or worst of all, a piece of hardware so compromised that it's not really good at either role. A wet-lab in the right circumstances may well offer you additional volume for little effort, as you put it, but it's also going to be of similarly little utility, too.

Not really and especially not with the Shuttle ET but that's also why JSC never liked the idea. Volume under pressure in and of itself can be argued either way as it depends greatly on what you do with it and how you fit it out. The S-IVB 'wet' lab only had floor grates and some wiring runs 'built-in' whereas for the most part the ET 'wet' spaces didn't even have that due to the way they were constructed. Where the main 'breakdown' occurs is what can you fit through an 'airlock' and get into that space being the main question. (Here's where I'm disappointed in e of pi/TimothyC's narrative because the use of the ASTP port as the 'main' straight-in port means that the space can't be utilized effectively no matter what anyone wants I fully understand WHY it's being done but I can't help but shudder at the waste)

Like the idea of inflatable pressure volume simply HAVING that volume available is a vast boon to future operations.

In saying all that I prescind from any criticism of the timeline, because I think e of pi and Timothy have (as always) done their homework and presented a highly plausible (and enjoyable, for me) scenario of a could-have-been. It's not even that harsh of a criticism of the Reagan Administration decision makers here, because what they're getting is a relatively quick hack that will get them the space Cold War PR win they want - an American space station with a f***ton of pressurized space in relatively short time. Now, I don't think it will be a terribly *useful* station, or at least, not the "wet" component at any rate (and I expect a lot of teething problems, to boot) beyond possibly playing zero-g lacrosse . . . but then again, an awful lot of those pre-ISS Shuttle missions really weren't all that useful, either, as a justification for the dollars spent (and risks run). At least now they have a permanent platform for the shuttles to go to, at least as lifeboat option if nothing else . . . certainly, at least, until NASA can come up with a plan and the funding to build a from-scratch station.

I agree with everything EXCEPT that it won't be a terribly "useful" station because it quite obviously will Because you don't learn from NOT trying something and one thing we SHOULD understand by this point in OTL's Space Programs is we have done far to little with what capability we DO have and significantly not enough with the capability we COULD have all because we don't really have a good idea what we WANT to 'do' in space. I fully expect that the 'extra' space, (and mind you we still need to see if that all gets into orbit at all rather than just being the 'planned' system ) will be deemed a failure and under-utilized but I'd hope that it would be seen as a planning and execution fault rather than in inherent flaw because it is the former not the latter. (As I noted ASTP hardware really kills your utility but on a 'better' note they can still 'hinge' the LOX nose-cone and have an OTV hanger as was one plan for ET use )

And while we're at it lets agree that while the OTL pre-ISS missions were often less than useful they also have a higher incentive TTL to actually utilize the Shuttle Orbiter less as a 'ad-hoc' Space Station because they have one actually IN ORBIT which is going to change priorities and mission options a LOT

Likewise, in saying this, I also prescind from any blanket endorsement of JSC on every space station architecture debate in that era, not least because as regards the best way forward for the Shuttle program in its first years, I think MSFC had the better of the argument. But that has largely to do with MSFC having a much more realistic appreciation of the political realities facing NASA's HSF program than JSC's leadership did.

That's kind of a given since when you look at who ran what during the time about the only one that did NOT expect the Apollo spigots to be turned back on 'any-day-now' it was WvB and his folks at MSFC and that because most of them 'grew-up' with limited budgets and support whereas JSC was born-and-raised on Apollo with all that implied. One of the interesting things about reviewing the NASA "space station" saga and timeline was noting that WvB had been pushing for a space station since early on, partially because this was how he and everyone else always 'expected' it to go but also because he was very aware that Apollo and the Lunar Landing Goal was an aberration and unlikely to be sustainable beyond a short period of time. He wrote that a more 'Earth resources' aimed program would have longer term public and political support and an Earth orbiting space station could and should play a part in that.

In a choice between engineers and astronauts on a question of, well, engineering, I think any sensible conclusion is almost always going to be on the side of the engineers! The engineers aren't fighting for mission assignments, for one thing. @groundhogday666's post up above gives us a timely case in point in this regard, alas.

Oddly the Engineers at JSC were more a minority than those who actually supported "wet-labs" In this regard it was more a question of who wanted a purpose built space station, (which is what JSC advocated for) compared to those who wanted something a bit more economical and utilitarian which is what centers like MSFC and Langley were aimed at. (The whole "purpose built" thing tended to bleed over into the use of things like inflated structures as well which is why JSC didn't like Langley's inflated concepts either ) "Engineering" decisions were very much not as 'straight-forward' as they sound. Specifically JSC's Orbiter payload bay size comes to mind which is routinely blamed on the Air Force rather than on JSC. Like the delta wings it was something JSC wanted that they used the Air Force "requirements", (not even the NRO who noted they in fact didn't need that big a bay, or that kind of cross-range) as a justification for the plan they had already made.

Randy

 

[JEF_300]

Wait? That was the Barkbarian? (misspelled on purpose ) I thought it was a four-engine Titan variant?

Barbarian was the name of the Air Force Program, but multiple rockets were proposed for that program. There was at least one Delta and one Titan based proposals, and I want to say there were also an Atlas and a SRB-X based proposals.

EDIT: I've yet to find a good visual of what the Martin Marietta Barbarian would have looked like, so you'll get this excellent diagram from Ed Kyle's website Space Launch Report. And for the sake of fairness, we'll use another Ed Kyle diagram for the MD Barbarian too. As you can see, both designs existed, and were of similarly absurd size.

 

[TimothyC]

Barbarian was the name of the Air Force Program, but multiple rockets were proposed for that program. There was at least one Delta and one Titan based proposals, and I want to say there were also Atlas and a SRB-X based proposals.

The Big Atlas (4+1 RS-27 class engines with four solid boosters and a Centaur-G' upper stage), SRB-X, and Titan 34D7 (Titan IVA) designs, were a part of the Complementary Expendable Launch Vehicle (CELV) program and not the heavy lift program that gets called 'Barbarian'.

 

[EDS_Pilot]

Yes! New e of pi/TimothyC alt-space timeline for Christmas!



Wait? That was the Barkbarian? (misspelled on purpose ) I thought it was a four-engine Titan variant?

And a question on the 'difficulty' of wet-lab operations; On the converse side I've only found mostly positive comments directed at operations of a 'wet-lab' design from the aspect of astronaut testing. Both the initial S-IVB wet-lab experiments, (in fact WvB climbed into a suit and did neutral buoyancy testing himself in September of 1968 with his only comment being the need for more installed hand-holds, see: https://history.nasa.gov/SP-4011/part2b.htm, https://history.nasa.gov/SP-4011.pdf) and later during testing of the Shuttle External Tank. Most of the complaints I've see were for the early MORL testing and specifically with the un-modified Mercury suits before they knew for sure about the cooling problems.

Randy

I think the four engine Titan was Large Diameter Core Titan III? And a wetlab ET would be like the SIVB wetlab, in which it would be drained of fuel after it got into orbit?

 

[JEF_300]

The Big Atlas (4+1 RS-27 class engines with four solid boosters and a Centaur-G' upper stage), SRB-X, and Titan 34D7 (Titan IVA) designs, were a part of the Complementary Expendable Launch Vehicle (CELV) program and not the heavy lift program that gets called 'Barbarian'.

Ah that's right, thanks. For the record, if you guys can somehow butterfly from that US intelligence failure into even a single Barbarian launch actually happening, I will love you forever. Barbarian is just so silly and fun. I mean, it's big enough that you could do lunar landing with one or two if there was a national will to do so.

Now there's an idea! Barbarian launched space-lasers in late 80s leading into a Lunar return before Y2K. I guess that's another timeline idea to add to my pile.

Great update by the way, as expected. It's always fun to see the engineering overcome the politics within NASA.

 

[RanulfC]

I think the four engine Titan was Large Diameter Core Titan III?

I seem to recall it came up again during SDI and was labeled the "Barbarian" which is why I was confused. Who ever heard of the USAF using a name more than once after all

And a wetlab ET would be like the SIVB wetlab, in which it would be drained of fuel after it got into orbit?

Yes the LH2 tank would be 'pacified' over several orbits being drained first of the liquid fuel and then purged of the gaseous hydrogen. Getting that last bit of hydrogen out before you introduce oxygen was a "bit" critical and there were a number of methods suggested. In the ET studies IIRC they ended up leaning towards an inflated 'liner' that was installed and later hardened on exposure to vacuum and helped stiffen the structure as well.

Randy

 

[e of pi]

Folks,

How about the Aft Cargo Carrier ? https://webcache.googleusercontent....-1982/+&cd=1&hl=fr&ct=clnk&gl=fr&client=opera

A combination of the ACC, wet workshop E.T, and Spacelab modules - plus the transformed Shuttle Orbiter... !

They did look at it in the same paper we used as the most direct base for Enterprise's appearance ITTL:



The downside is that while it's easier to build useful volume into the ACC docking module than an intertank docking area and easier to provide other docking ports, you (1) have to run a pressurized passageway further through the orbiter, including the boat-tail with all the propulsion systems and plumbing and (2) you access the hydrogen tank first. The LOX tank is more usable early on in conversion by virtue of being a little smaller, and using the intertank access we decided to go with has direct access to both tanks from the docking module. Also, you have to fabricate the ACC, which is a new program distinct from the minimum needs of Enterprise, and Reagan's telling them to hurry up and get Enterprise up there before the Russians launch their big Energia station.

 

[RanulfC]

They did look at it in the same paper we used as the most direct base for Enterprise's appearance ITTL:

View attachment 612362

Ok I thought I'd seen that but it was in this post with the first illustration of the "Space Facility" duel-keep ET design not a Shuttle based one...

Though the second picture in the annex (General Dynamics/Convair "Enterprise" Based ET Facility) has an interesting 'nub' on the base of the LH2 tank and (obviously) some sort of implied connector on the LOX tank as well.

The downside is that while it's easier to build useful volume into the ACC docking module than an intertank docking area and easier to provide other docking ports, you (1) have to run a pressurized passageway further through the orbiter, including the boat-tail with all the propulsion systems and plumbing and (2) you access the hydrogen tank first. The LOX tank is more usable early on in conversion by virtue of being a little smaller, and using the intertank access we decided to go with has direct access to both tanks from the docking module.

Well you don't HAVE to run the extra passageway as we all know the astro-hamm, er that is Hamsternau... I mean of course the brave crew, needs their exercise! Just because the Hagen Corporation won the contract to construct the passageways has no bearing on our support and encouragement of those fine people being smarter than your average bear.. Hamster.. Guinee pig... You know what? Never mind, just enjoy the complementarily snacks we left parked in odd corners ok?

And while we're wishing they also studied mounting low-mass, high volume cargo forward of the LOX tank as seen in this paper (page 4) up to a pretty large hammer-head, (figure 8 through 11) but we'll leave off the "lenticular" design (figure 12 and 13) for the moment... (But JUST for the moment ) Because...

Also, you have to fabricate the ACC, which is a new program distinct from the minimum needs of Enterprise, and Reagan's telling them to hurry up and get Enterprise up there before the Russians launch their big Energia station.

it's a rush job so we can't have everything and while they'd done some preliminary work the main work was still to come. I'd like to believe that some of this could be fitted out on-orbit but frankly it's a shoe-string project and I doubt much (if any) of the "extra-space" is going to be utilized anywhere near as much as it could be.
(Surprise me maybe? )
What it boils down to is that there are no suitable space suits to actually allow the activity range and work utility that's really needed to access and utilize the spaces provided. The Apollo suits were bad the Shuttle suits were worse and there's not really an incentive to actually change anything to promote or incentivize NASA to put forth the effort. No one ever saw a need for an actual "space work suit" so no one ever designed one, (ok actually people HAVE done so but it got buried by the Apollo focus, then the Shuttle focus, then the ISS focus but you get the idea) and as this is the 'tween' period where interest in Space Colonies and Space Solar Power were dying out and SDI had yet come to the fore such an effort isn't as likely as I could hope.

The thing is of course the SPACE is there and available so naturally the astronauts are going to use it for 'something' at some point and the station WILL expand somewhat into it so we'll see I suppose (I hope )

Randy

 

[Athelstane]

Och aye - you wear me out, Randy...

While those are minutes those astronauts are NOT going to be conducting science or technical tasks that's not a very good argument since it is likely tasks that are going to have much BIGGER relevance down the road if you plan on having any on-orbit work or assembly planned down the road. Note that JSC never DID have such plans whereas places like MSFC and Langley DID have such plans which is where the interest came from. JSC always planned as few orbital operations or EVA's as possible by design because, (as you note even though not directly) they didn't 'trust' human activity in or outside of a spacecraft. (Despite being the "Manned" Space Flight center) While granting there was no way of knowing it prior to Skylab's launch they in fact DID spend an inordinate amount of time 'fixing' Skylab anyway which was invaluable lessons and learning that would not have happened had things gone as planned. (And even THEN NASA faced a revolt due to the their un-reasonable work schedules)

What I would say is this, if I may: "that's not a very good argument since it is likely tasks that are going to have much BIGGER relevance down the road if you plan on having any on-orbit work or assembly planned down the road." That is all well and good, in aggregate, but my concern, and I think it was a reasonable concern to the extent shared by JSC planners, is that you gotta crawl before you can walk. And crawling was basically where NASA was in terms of microgravity life and tasking in 1969. Spend some time first simply seeing how humans function on a basic level in microgravity for a few months before asking them to build a home in it?

Pete Conrad and friends *were* forced to do some repair work anyway, it's true, but I might also point out that a) it still only amounted to 4 hours or so of EVA work (they still managed 400 hours of science work in a 28 day mission, after all), and b) on EVA 2, Conrad and Kerwin very nearly got turned into permanent low earth orbit satellites when the solar panel release flung them off the station exterior, saved only barely by the strength of their umbilical cords.

All this is admittedly Skylab-specific critique on the wet workshop question, of course. But I think it helps paints some of the outlines of why going "wet" is . . . not impossible, but certainly problematic. I don't doubt NASA will make it work somehow in this timeline - and learn from the experience - but I would not expect it to be easy, and I would be sober and restrained in my expectation of what could be achieved with the ET pressurized volume. Mainly, it's going to be a learning experience that gets them one day to a station wholly designed to be such.

 

[Kirk Kerman]

Aside from any questions about Wet Workshops, I do wonder where NASA will turn in terms of something like Freedom's ACRV. Obviously it's far too early since the Shuttle started for NASA to develop their own, Hermes is not close to being ready, and Soyuz is definitely not in the running!

 

[Thoresby]

What I would say is this, if I may: "that's not a very good argument since it is likely tasks that are going to have much BIGGER relevance down the road if you plan on having any on-orbit work or assembly planned down the road." That is all well and good, in aggregate, but my concern, and I think it was a reasonable concern to the extent shared by JSC planners, is that you gotta crawl before you can walk. And crawling was basically where NASA was in terms of microgravity life and tasking in 1969. Spend some time first simply seeing how humans function on a basic level in microgravity for a few months before asking them to build a home in it?

I think this is the crucial point. If you were given absolute control over NASA's development path for 40 years from 1960 with a goal of a large self-sustaining orbital presence in the year 2000 I think the space habitat element would consist of:

Long duration orbital craft trips>Small purpose built space station>modular space stations with "wet" and "dry" elements moving increasingly to expanding via wet modules as your in orbit capabilities improve. Ideally you'd have a real habitat consisting of lunar sourced bulk material combined with earth launched machinery assembled in orbit in the pipeline but that might be too optimistic even with 20/20 foresight.

 

[TimothyC]

Anyways, awesome start so far! I see Nixonshead credited, does that mean that we'll be seeing more of his gorgeous renders?

Yes, but they won't show up for some time yet, and we have some other images that will show up first.

 

[Athelstane]

Yes, but they won't show up for some time yet, and we have some other images that will show up first.

Looking forward to it!

 

[e of pi]

Boldly Going Part 3

The scope of the issues encountered as Marshall and Johnson began to allocate work and dig into the challenges of converting the Shuttle stack into a functional space station could hardly be understated. Even in fall 1983, as the project teams were still forming, many argued that the effort of converting a Shuttle into a station would be better invested in a clean-sheet station more like previous studies of Shuttle-constructed designs. NASA had spent a decade imagining how to assemble a station launched with the Space Shuttle, but the Shuttle-converted station was relatively immature. Questions quickly arose if the Shuttle-derived station was truly faster or more capable than a Shuttle-assembled station, and lingering debates on value for money and available schedule margin would haunt the project over the next several years as costs and scope spiraled and budget requests had to be altered in turn. If fears of Soviet stations had never reached their 1984 peak and the true upper limits of Mir planning had been better realized, it is possible that the Space Station Enterprise program might have been abandoned and alternate projects might have replaced it--whether for better or for worse, depending on the premises of various counterfactuals. However, much as the American Shuttle had been mis-identified as a military bomber by Soviet scientists skeptical that Americans would invest such funds and develop such a rocket based on the shoddy mathematical projections of demand which underlay many early Shuttle studies, leading to Energia and Buran, so too were Americans able to convince themselves that Buran’s existence and rumors of its ability to launch very heavy monoblock payloads on Energia must mean that Mir was, indeed, merely the start, another stepping stone to a massive presence in space. It was as much of a fantasy as the legends of the lost city of Atlantis, but it meant the White House continued to evaluate Space Station Enterprise as a priority through critical years as hardware began to be constructed.

The program wasn’t all hassles, however. For every challenge as daunting as the Orbiter system and structural revisions, there was one which was fairly straightforward. In 1984, while Palmdale and Johnson contemplated the first cuts into OV-101’s structures, the production of a permanently-orbital Spacelab module was already underway in Italy. While Marshall wrestled with hamster tube inflatable intertank corridors and the challenges of foam which was too well sealed and yet too poorly attached for long-term use, other teams were issuing final contracts to begin production of the station’s initial 50 kW Enterprise Power Module (EPM), derived from a 25 kW Power Module originally studied for either a salvaged Skylab station or for Shuttle-Spacelab mission extensions. The summer and fall of 1984 would be remembered as the nadir of the program, as Space Station Enterprise managers dodged questions about its justifications and tradeoffs from Congress and internal dissent from other NASA station planners who had seen their concepts discarded for a makeshift alternative.

However, much like the station they would eventually build, the Space Station Enterprise Program Office was only passing a perigee, not seeing their flight come to an end. There was a launch at the end of the tunnel, more real by the day--and if that pressure was immense on the schedule and budget, it was also the lure which drew teams on to solve the challenges of the project in sequence. One by one, systems and subsystems passed from preliminary design reviews to critical design reviews, then into prototyping and fabrication. Day by day, men and women went to work and metal began to be formed into parts. In Michoud, a new External Tank began fabrication, assigned the unused ET-007 number originally assigned to the cancelled final Standard Weight Tank. This unique one-off modified tank would serve as OV-101’s ride to space, and gained many nicknames as it proceeded in halting fashion through both standard and radically altered manufacturing phases at Michoud, gaining nicknames like “The Heavyweight Tank” and “Moonraker”. Meanwhile, the Palmdale team began the modifications to OV-101’s primary structures. Progress, when it came, was immediately visible. Engineers tore apart OV-101’s aft boat tail to begin the installation of a fully-functional main propulsion system, preparing the propellant lines to feed real RS-25s where the orbiter had only ever carried simulators.

The most notable changes which distinguish Enterprise from her sisters to this day came next: the great wings which marked a Space Shuttle were clipped. As with other systems removed from Enterprise such as landing gear actuators and doors, this process was not as simple as cutting torches and saws, as was sometimes joked earlier in the process. The orbiter’s wings and tail were some of the most critical long lead structures, and the addition of an extra set to the spares stockpile for maintenance of the rest of the fleet was immensely valuable.[1] Many of the systems required for flight which would require conversion, such as radiators, tanks for cryogenic fluids, OMS and RCS, radars, and star trackers had simply never been installed. Another notable system which had gone uninstalled during Enterprise’s first time at Palmdale was the Shuttle’s internal airlock, and unlike other systems none would be installed. Instead, an external airlock derived from the same design would be included aft of the Spacelab module, just forward of the mounts for deploying the power module from the bay. With no requirement to land, the bay could be loaded with a mass distribution incompatible with the center of mass requirements for a landing. These limits applied to every regular orbiter even for payloads to be deployed on orbit, in case an abort brought them back to land. One way or another, such landing concerns didn’t apply to Enterprise. Instead, every open compartment could be loaded as necessary as crews tore open Enterprise down the structural level.

Every kilogram saved in removed tiles and clipped wings (and more besides) came back as the station’s hungry systems swallowed the project’s weight margins at a terrifying rate. Six thousand pounds of landing gear was reborn as the mass margin for the new pressure tunnel linking the intertank to the belly of the orbiter and its ascent fairing. Twenty thousand pounds of tiles melted into an entry on a weight and balance sheet and emerged as the margin for the intertank tunnels themselves. Two thousand pounds of fuel cells and related hydrogen tanks were removed, replaced by the tie-ins for the new solar power system Marshall was building to mount in the bay. Twenty thousand pounds of wing and tail structures and actuators would be reborn as modifications to the systems critical to support the orbiter’s flight in her new home--augmented thruster propellant supplies, systems to ease remote operation of the station between crews, tie ins for the power module to the old fuel cell busses, and the systems to resupply everything possible in flight. All told, more than 20 metric tons of additional payload were added through removal of unnecessary systems. Some had to be unbolted, cut, or otherwise removed, as were Enterprise’s wings and tail. Others, like the tiles of the Shuttle’s thermal protection system, were simply never installed since they had been left off for Enterprise’s glide test career. Much of the weight removed came back as ways to enable long-term operation of a spacecraft originally designed for mere weeks in space. The 45-inch diameter fuel cell hydrogen supply tanks were replaced by new tanks of similar volume to augment the station’s oxygen supplies. A 700-pound system was added to interconnect the forward and aft RCS supplies, including valves for resupply tanks to be coupled in the future. Additional water tanks had to be incorporated in the cabin. By 1985, the design had largely stabilized, and with it the total launch weight at nearly 150,000 kilograms--more than the performance of a Saturn V and almost twice the launch mass of Skylab. Major hardware like OV-101 and ET-007 were already in hand for conversion at their respective subcontractors. New design hardware for the conversion like the modified European Spacelab module, the new airlock, the Power Module, the revised crew cabin systems, and the external tank’s “hamster tubes” were beginning to be built in production forms. The slips in the program’s schedule shrank and the launch date began to stabilize. Against all odds, it looked as though a launch might truly only be two years away…

[1]This was historically done in 1985 when Enterprise was delivered to the Smithsonian. All serviceable flight units were removed, including the landing gear struts (some of the most vital and complex forgings on the orbiters) which were eventually used on OV-105. Enterprise received the engineering units from the LGTA-090 test rig in their place. (Jenkins I-448,9)