The Construction of Space Shuttle Launch Complex 39-B
A very personal and technical written and photographic history, by James MacLaren.
Page 61: New OMS Pod Covers, Preparations for the ARCS Rooms, and Much More.
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And the Pod Covers went up, and everything behind them will no longer be visible from the ground, and you see them here in the center of the frame, illuminated by a high summer sun, with the shadowing of things on the tower giving us a time, late morning, 10 or 11, local solar time, and an approximate date of June or July, 1983.
79K24048 was about to kick into gear for real.
The modifications to the PBK and Contingency Platforms which we encountered early on with the 79K24048 grab bag back on Page 53 remain visible, but notice that the Folding Stair and Contingency Platform shown here on 79K24048 sheet S-166 on both sides remain unerected.
Hmm...ok.
And then we look a little closer at the photograph, and we see that both Stairs to the TSM's, depicted on sheet 79K14110 sheet M-34, with all of their access catwalks and hanger framing, are missing, too.
And then we look closer still at this photograph (which was taken at an extraordinarily lucky time), and...
...sonofabitch, but the goddamned Stairs to the TSM's are down there on the ground, in a pile, and clearly, in order to make it a little easier to put the Pod Covers on the face of the RSS, the PBK Folding Stairs were kept out of the way by not even bothering to hang them on the tower until they were no longer an interference, and yeah, ok, that makes sense, but...
What's going on with the Stairs to the TSM's laying down there on the ground?
Well...
This (and more... much more... which is coming) stands as mute testimony as the the awful fuckedupness of 79K24048, and all that it stood for, and all that it represented. And all that it represented consisted in what they discovered, what they had forced on them, as they began flying Space Shuttle missions over on Pad A. Yes, there's plenty more in 79K24048 which was well thought-out in advance, and which they knew from day one was going to be necessary to finish out the towers, but...
...buried down in there with all the rest of it...
...was a LOT of stuff that nobody ever saw coming until it knocked them upside the head, without warning.
And we've already been introduced to the concept, and I've railed against it while telling you about the Hammerhead Crane TPS Inspection Spider Basket Trolley Support Extensible Pipe Boom Psychosis on Page 55, and I've railed against it while telling you about the PBK & Contingency Platform Mods on Page 53, and other places too, and there's LOTS more you'll never get to hear about...
...but the sense of the thing is that...
...they built this goddamned thing, and they started flying the goddamned thing, with people in it, without having fully understood what the hell it was that they had built, and had flown, with living human beings inside of it, and as cruel experience continued to enforce itself upon them, they found themselves having to scramble, and find solutions, to problems that nobody had ever thought of, some of which were potentially fatal, near-term, long-term, directly, and indirectly, and that which was forced upon them accumulated, and became...
79K24048!
And if that doesn't scare the living fuck out of you, then clearly, you have no idea what was really going on out here.
Don't get me wrong.
I'm ALL for iterative hardware-rich design/build/test programs.
All for it!
But godDAMN, don't go putting PEOPLE inside the fucked-up thing while you're still working your way through the tall grass, and you're occasionally still finding goddamned tigers hidden in that tall grass!
Get that shit squared away FIRST!
Then, and only then, you can start putting goddamned crew inside of it.
But that's not what they did.
What they did, was they believed their own bullshit.
And before the program was over, they killed FOURTEEN good men and women, in the air, and more on the ground...
...and nobody...
...ever...
...was brought to accounts for it.
And they should all be very glad that it wasn't me who got put in charge of bringing people to account.
And as a result of what they did, monstrosities like 79K24048 came into being, and had to be implemented, as they kept discovering things, while continuing to fly their crewed vehicle.
And for whatever reasons unknown to me, one of the things that was included in 79K24048 was what we called the "ARCS Rooms", located here on 79K24048 sheet S-130 in general arrangement plan view out on the Pad, but which on all of the drawings were called "Platforms For APU Carts" or the "APU Storage Area" as can be seen here on 79K24048 sheet S-138A and of course, in keeping with the infuriatingly chopped-up tone and tenor of these hideously crummy PRC/BRPH drawings, trying to call them any kind of "APU" anything only makes matters much worse, because, we're down here in Lower Hypergol World on the APS Servicing Platform Level at 112'-0", and the goddamned motherfucking APU Servicing Platform Level is at 125'-0" directly over your head when you're on the APS Servicing Platform, and...
What the fuck? Over.
So I guess to keep things making enough sense, out on the jobsite, everybody very sensibly decided to shitcan any and all talk of any "APU" anything at all when working down on the APS Level, and of course, the daffiness of it all is not quite thereby eradicated, because the "RCS" in "ARCS" of course stands for the FORWARD Reaction Control System (which is why the RCS Room was called the... wait for it... RCS Room!), but for unknown reasons, the AFT Reaction Control System had to be specifically invoked by tacking that "AFT" in front of the "RCS" and...
AAIIIIEEAAAARRRHHHGGGG!!!!
What. A. Bunch. Of. Fucking. Bullshit!
And this is what invariably happens when you put engineers in charge of anything that involves the English Language, and really, somebody needs to see to it that these people are kept far enough away from things having to do with the English Language to prevent them from killing somebody, and if you think that's an overstatement... you have not yet spent enough time in this field of endeavor, because people do get killed as a result of this exact thing. Engineers are, by and large (yes, there are plenty of exceptions to it), lousy communicators, and lousy communication has killed too many people to count over the years, and it continues to kill people, and... gettitouttaheah!
So ok, so how 'bout we try to bring the discussion back around to what's showing in the photograph up at the top of the page, hmm? The photograph showing us the Stairs to the TSM's down on the ground in a heap.
And it turns out that it's easier to just simply go after the TSM Stairs along with their access catwalks and hanger framing, and simply cut them down, and then put them back up when you're done, than it is to try and work all this new ARCS Room stuff (which, remember, extends upwards to the underside of the 125'-0" steel directly above it) without the freedom to move around and the significant speed-up of the work, that you get from just snatching those stairs off the tower and laying 'em down on the Pad Deck till you're done.
It's not the easiest thing in the world to visualize, so I've altered 79K24048 sheet S-130 to (hopefully) let you see the 112'-0" Level in both configurations, with the new ARCS Room steel, and the old TSM Stairs and Platforming hovering just above it before they went to the ground (and after they came back up, too, for that matter), but it's still a little jumbled up in there, and if it fails to sensibly register, don't worry about it, and just leave the Union Ironworkers alone, and let them do what's best, because they know what's best, and we won't have to worry about it, ok?
And yes, it was easier to take all that stuff down, but no, nobody in their right mind would have ever set things up this way in advance, deliberately, and...
...79K24048, and all of the things which that number represents...
...no small amount of which was...
...pretty scary.
I mean...
If they were missing this kind of stuff on the towers...
...what were they missing on their flight hardware?
...and you never want to be doing stuff this way...
...but 79K24048.
In and of themselves, the ARCS Rooms weren't much, but they were distinctive enough that once they were finish-framed and sided, they altered the appearance of the RSS, and it then became one of those "I wonder what that stuff is for?" deals where you see them down there in photographs, on either side of the tower, for the period of their existence anyway, and at some later point, for reasons I have not yet learned, the one on the left, RSS Side 2, the Column Line 7 side, lost its siding, which changed the visual noticeably, and the one on the right had its "window" cutout (we'll get to that in a bit) modified, which also changes the visual, just a little bit, and...
And this is the place where, before they built these things, the hoist that rolled back and forth on the monorail that passed through the Doors of Doom was located, and we learned all about it back on Page 24 when I really started digging in (and, if you haven't already, maybe read a little farther than you might, ordinarily, maybe all the way down till you get to the word "Brrr"), and there were a couple of links on that page to excellent general arrangement drawings of this whole area/system, and I'm gonna put links to those drawings here too, and in the first link, to 79K14110 sheet M-40, you get to see how they rolled the APU Valve Complex out there on top of the MLP, and hooked on to it with our hoist that lived beneath that monorail just under the elevation 125'-0" Floor Steel, and in the second link, to 79K14110 sheet M-42, you get to see this stuff with the APU Umbilical attached to the side of the Orbiter, and, as I mentioned earlier, it's quite the elaborate system, but it works well, and that's how they did it, but at some point, somebody decided that the RSS needed a little something extra down here, and that something extra is our ARCS Rooms.
And when the ARCS Rooms appeared down at 112'-0", the requirement for those Doors of Doom promptly disappeared, because there was now proper platforming on the other side, which means you were no longer at risk of falling through when you stepped beyond the Doors past the limits of the platforming as it had previously existed, and the Doors were caused to disappear, and in fact, that entire wall was caused to disappear too, and the sided-in area expanded to the outboard perimeter of the new ARCS Rooms wall framing, and all well and good...
But what about the APU Valve Complexes that got lifted up there to the 112'-0" Level of the RSS on both sides, using those Monorails which were bolted to the underside of the 125'-0" Floor Steel, and which extended way the hell outboard all the way to a point where their terminal ends were even with the Hypergol Spill Ducts?
And it's a thing you'd never think about...
But were you to not think about it...
It would get you...
And so...
Ye gods! Everything is connected to everything and you can't touch anything in this place without fucking something else up in some devious and indirect way...
So ok, let's look at that for a minute, ok?
Let's back up all the way to that Monorail, and the job it has to do, and why that job locates it is where it is, the way it is.
The Orbiter uses copious amounts of hypergol of two different kinds, for three different systems back there at its aft end, and hypergol being hypergol, you're gonna be handling it with care, using specialized servicing equipment to do so, and the specialized servicing equipment down here at 112'-0" includes those APU Valve Complexes that get picked up by the hoist which hangs from our Monorail, and which are specifically for the APU's only (and here they are again, in a much more simplified view to help you get a better sense of what and where they are, complete with Aft Compartment Access Doors 50-1 and 50-2 highlighted), which were MONOpropellant, and which therefore deal with HYDRAZINE only.
And for reasons I have yet to fully come to terms with, NASA did not want those things as permanent fixtures down where they got used in Lower Hypergol World. I think it's because the whole Pad was fitted and plumbed for the bi-propellant kind of hypergol that they use vastly more of for OMS and RCS, and the monopropellant hypergol which fuels the APU's got consumed in relatively tiny quantities which could be furnished to the Pad as-needed, in a tank inside a box more or less, which means, for every Space Shuttle mission, the APU Valve Complexes containing that monopropellant hypergol would simply get taken out to the Pad, get picked up, get taken to their servicing locations on the 112'-0" Level, get used, and then get removed from the tower and then the Pad, when they were done with them. Every mission. Every time. But I'm not completely sure of myself with this, in particular the business of transporting hydrazine inside the APU Valve Complexes, so you need to be aware that I'm... guessing with this one, and unless and until I find solid documentation on this, that's all it's ever gonna be. A guess. Ok?
The other main component of the specialized hypergol servicing equipment at 112'-0" was the Hypergol Umbilical Carriers, which we met before on Page 24, but that was back when I was working for Sheffield Steel, and the Hypergol Umbilical Carriers did not get furnished and installed until later on, when I was Working for Ivey Steel (which of course is the block of time we're dealing with now in Part 2 of this narrative), and the Hypergol Umbilical Carriers (nobody ever referred to them using an acronym, and they were always referred to by their full name, and no, I do not know why) took care of BI-propellant loading for the OMS Motors and the Aft Reaction Control System Motors, and those things were for both hypergolic fuel AND oxidizer, with the one on the left side as you faced the Orbiter, RSS Side 4, handling the MONOMETHYLhydrazine fuel, and the one on the right side, RSS Side 2, handling the nitrogen tetroxide oxidizer.
Back on Page 24, when we first learned about the Hypergol Umbilical Carriers, we were still working our way through simply getting oriented with the bewildering complexities of the RSS as a structure, and I did not elaborate on them at the time, in the interests of not overwhelming you, and right now, in those same interests, I'm going to to continue to leave them alone, and we're going instead to deal strictly with the APU Valve Complex along with it's ancillary gear on the tower, ok? For now, that will be plenty enough, and the rest will come, soon enough, but not right now.
What I will do right now, is give you a little bit more on the APU's.
These things were not trivial. People in "normal" technical disciplines who are familiar with APU's in passenger aircraft (and they show up elsewhere, too) tend to regard them as just another standard-issue component on the aircraft, and for aircraft, this is certainly the case. It's an exceedingly well-understood technology, fully-mature, and the production, operation, and maintenance subdisciplines for aircraft APU's are in no way unusual or "cutting edge." It's all just another day on the job, ok? The job might not be easy, and there might be significant penalties for doing the job wrong, but it's no different from any other well-understood technological job, and if you lose your APU while you're in the air, so long as your jet engines keep running (without which things rapidly go from bad to worse, with or without a functioning APU), you'll be just fine.
APU's on aircraft are smallish gas-turbine generators, essentially small jet engines, sucking in the same oxygen from the air, and burning the same jet fuel, that powers the big engines that push the aircraft to high enough speeds to make it fly, and there's one of them per aircraft.
And every bit of that shit goes right out the window, just as soon as you switch your APU fuel from the commonplace stuff that jets drink to...
...hydrazine.
And in fact, a pretty good case could be made for no longer even calling it an "APU" once you've switched over to hydrazine to power the goddamned thing, because except for the fact that you're using hot high-pressure combustion exhaust gasses to spin a turbine to extract useful work from, there's nothing about one of these things that is in any way similar to what everybody else calls an "APU."
Hydrazine is weird shit, and it's dangerous like a motherfucker, and I've repeatedly attempted to instill a proper sense of fearful respect for the stuff in you, 'cause if you ever encounter it in your daily affairs, whether in a controlled environment (this, we like), or, god-forbid, an UNcontrolled environment (this, we do NOT like), you must always exercise your full situational-awareness of things...
...lest you wind up in the hospital...
...or dead.
And that's a real attention-getter right there, but the stuff isn't done being weird, and one of the additional weirdnesses of hydrazine is that it can be used as a MONOpropellant, and your situational-awareness of the full meaning of that "MONO" that gets tacked on to the front side of "propellant" may or may not be enough to cause you to stop and go "Hey, wait a minute, that ain't right," and then maybe try to understand what's really going on with... mono? propellant?
How the fuck does a thing like that even work?
And once that question has set itself down into the folds of your brain, then and only then do you stand a chance of understanding this particular weirdness of hydrazine, and how it relates to the APU's we're dealing with on our Space Shuttle, and the fact that there's a fucked-up Monorail on the RSS somewhere that somehow, maybe, we'll be getting back to, to finish telling the story of the ARCS Rooms as expressed in 79K24048, and... good lord! Not another one of these deals!
Chains.
It's all fucking chains.
Chains of reasoning and chains of cause and effect.
And everything is connected to everything, and it's all interconnected to itself through chains of reasoning and chains of cause and effect, and stupid people steadfastly refuse to fully work through the full lengths of those chains, because they're lazy, and The Path of Least Energy drives them toward being lazy, and if they can get you to do the work, then that's exactly what they'll do, and the worthless fucks get over on you in so doing (making them temporarily smarter than you because... you fell for it, right?) and la la la, except that it puts them in a horrible position of dependency, and if the shit ever really hits the fan, then all of a sudden you're not there to fall for it and do the work for them anymore, and since they're stupid, they can't do the work for themselves, and all of a sudden... they're FUCKED, and The Path don't give a rat's ass, and it will chew them up and destroy them, and those of us who are not stupid will continue to Survive and Reproduce, which is the only thing that The Path of Least Energy cares about, and yes, it actually is a good idea to burn a little extra energy when the world around you is providing the resources to do so, 'cause that makes you smart (so long as you burn it wisely and do not squander it on mindless entertainments and diversions), and one dark day... that might turn out to be a Good Thing, so... follow the chains of reasoning, follow the chains of cause and effect, identify each and every link in whichever chain it is that you're dealing with, and learn to understand each and every link in the chain you're dealing with, and... yeah.
And everybody (except the stupid ones) knows that propellants (for rockets, and for other things too, and the gasoline in a car's gas tank qualifies a propellant for the pistons in the engine, for example) almost always come in the form of fuel and oxidizer, with the fuel taking the form of a substance which is some chemical or combination of chemicals, and that substance reacts chemically with the freely-available oxygen in the air (often enough, anyway, but there's waaay more than one way to skin this cat, and the use of oxygen as a reactant is only one of those ways) and that reaction is happily exothermic, and it's the release of energy that the exothermic chemical reaction provides us with, that pushes or powers or otherwise energizes whatever it is that we're pushing or powering or energizing with our propellants, which of course is why we go to the trouble of making and using propellants in the first place.
Easy enough concept to deal with.
Until fucking hydrazine comes along, and starts acting all weird.
Yes indeed girls and boys, hydrazine works perfectly well as a "normal" propellant, used as a proper fuel, and will cheerfully react very exothermically indeed when chemically combined in a high-speed exothermic reaction with an appropriate oxidizer (nitrogen tetroxide is a favorite, but it's by no means the only one)...
...but there's more going on with hydrazine than just that.
Let hydrazine come in contact with a well-tuned catalyst...
And holy shit, it's Exothermic City...
RIGHT NOW...
Without ANY oxidizer!
And that's just fucking weird.
And it's all about the catalyst, and that turns out to be quite the Rabbit Hole in and of itself, and if you'd like to take a little side trip with it, well then, here you go, have ya a little HYDRAZINE CATALYST PRODUCTION - SUSTAINING S-405 TECHNOLOGY to chew on for a while, and yes, it's deeply fascinating stuff, and I highly recommend you stop and take the time to read the whole thing. Worlds inside of worlds inside of worlds.
Used as a monopropellant, hydrazine is a little less energetic than when it (or, better, MONOMETHYLhydrazine) gets used as a bi-propellant in conjunction with (usually) nitrogen tetroxide, and for applications that can suffer the additional complexity penalties of bi-propellant equipment in exchange for higher energy yields... well then, that's what they do, and that's why you get monomethylhydrazine, nitrogen tetroxide, bi-propellant systems for the OMS Motors and the Reaction Control System Motors on the Space Shuttle.
But when you get to the APU's, all of a sudden, the drawback of somewhat lower energy release (compared to rocket motors exclusive of smaller attitude-control thrusters, the requirement for energy yield in a gas turbine is much lower, thus giving you quite a bit more leeway in your design choices for this stuff) is more than compensated by the increase in simplicity of the hardware, and the reliability that goes along with that simplicity, and for that very good reason, they switch to straight hydrazine as a monopropellant. One set of propellant tanks instead of two. One set of propellant plumbing and valving instead of two. One set of... everything instead of two. Half the stuff to go wrong, to break, to maintain, to... you name it. Better. By far.
And unlike the APU's on an aeroplane, which you can lose, in the air, and still come home safely, with the Space Shuttle's APU's, if you lose them in the air...
Everybody dies!
Loss of vehicle, loss of crew.
Penalties don't come any harsher than that.
Lose your APU's, and you lose your SSME Thrust Vector Control gimballing, SSME Control Valving actuation, Orbiter Aerosurfaces control/actuation, LOX/LH2 17" Disconnect Umbilical Retraction at External Tank jettison, Landing Gear deployment, Landing Gear brakes and anti-skid, Nose Gear steering.
Any one of which is lethal, and all of which, taken together, is fucking BRUTAL.
And so, in consideration of the... situation... with the use of APU's on the Shuttle... they decided to furnish and install THREE (they only needed to have one to do the job) COMPLETE INDEPENDENT SETS of them (they really really did not want to lose their APU functionality), back in the Aft Compartment, back there in the area below the front end of the Orbiter's Tail... and since there was no air for any kind of normal propellant to react exothermically with to produce hot gasses to spin a turbine during much of their usage regime... they had to go to some kind of system that either used bi-propellant, like the SSME's (LOX/LH2) or the OMS and RCS systems (MMH/N204), or dispensed altogether with any kind of bi anything, and they had an overarching demand for high energy-density and simplicity and reliability... and all of that... forced them into using fucking hydrazine for these things, and all well and good... on paper... but holy shit did it ever open up more other cans of worms than you can sensibly imagine.
Hydrazine-powered gas turbines are...
...different.
Very very different.
And unforgiving, too.
And there are times when the cure can be worse than the disease, and this is one of them... ...although it didn't get them... ...but it tried.
So ok. So it's hydrazine, already. So they wanna pick it up off the deck of the MLP in the APU Valve Complex, already. So alright, already!
So give it a rest, already!
So.
Back to the Monorail.
Which needs a location, and a length, and we already know all about the end of it that terminates over the work area in Lower Hypergol World, and the other end of it needs to be out there directly above where the stupid Valve Complex is sitting on the MLP, and you can see right where that location and length puts you on the RSS, on this marked-up copy of our photograph up at the top of the page, and when the MLP is sitting on top of the Mount Mechanisms out on the Pad, and the RSS has been swung around into the Mate position, that all adds up to the requirement for the far end of our Monorail extending damn near all the way out past the Hypergol Spill Ducts, and originally, that put it over the side where there's no end of wide-open space to lift and lower things, but now they're putting these ARCS Rooms on the tower out there, and it ain't over the side anymore, so they had to make trapdoors in the ARCS Room floors, or otherwise the hook on the hoist, and whatever it might be that you attach to the hook on the hoist, ain't gonna happen no more, so... ok.
And we can see all of that for ourselves by starting out with 79K14110 sheet M-38, which gives us a general arrangement in plan view of the 125'-0" APU Servicing Platform level on the RSS (which of course corresponds to the "roof" of our new ARCS Rooms down below at 112'-0"), and which tells us that our APU Valve Complex Hoist Monorail is located 3'-3" off of Line B.7, toward Line A, extending out to the side, nearly beyond the Hypergol Spill Ducts, back there behind them.
And now we can go to 79K24048, sheet S-138 (which is uselessly labeled "RSS El. 112'-0" Fixed OMS Platform Details", and which is also very coy about what this thing is, or what it's made of, above and beyond that cryptic little note telling us we're gonna need a ⅜"Ø Recessed Rod Handle in 4 places) and we see that the centerline of our new Trapdoor (which is actually just a pair of flip-ups that face one another) is right below the Monorail, that selfsame 3'-3" back from Line B.7, directly, precisely, exactly... hey, wait a minute, it's a goddamned quarter inch offset toward Line B.7 (note that 2'-7¾" in Section P on 79K24048 sheet S-139!) , and no, I have no fucking idea why, but I've got a sneaking suspicion somebody goofed up with the locations of those W8x13's in there and didn't catch it in time, and then somebody else (in charge) said, "Fuckit, just go ahead and let them build the goddamned thing the way it shows on the drawing and maybe nobody will notice." And it's only now that we finally learn this thing is made out of aluminum, complete with an aluminum reinforcing beam welded to one of the Trap Door panels, and it has hinges, and why it needed to be made out of aluminum when every other goddamned flip-up on the tower is steel, I'll never know, and either way, there can be no doubt about what this thing is, or what it's for, or why they had to trapdoor it this way. But... 79K24048. Sigh.
And just to finish off with this ridiculous Tale of the ARCS Rooms, we can head on over to 79K24048 sheet S-138A and take a look at how they sided these little Rooms in (and while we're here, we can also take disgusted note of how the worthless PRC/BRPH fucks insisted on flipping back and forth from one side of the RSS, Side 2, to the other, Side 4, in their differing Plan Views for this stuff, opposite-handing things each time with a left/right reversal, and which side of the RSS are they showing us this time?, for no sensible fucking reason at all, above and beyond just being miserable lazy fuckwits about it and not caring how much trouble and potential mistakes a thing like that will cause for the people who have to use this crap in order to build something), and out there on the front side, RSS Side 1, they put little "window" (there's no glass, it's just a simple opening) cutouts in the insulated metal paneling, and I never did learn why, but they're perfectly located for somebody to be standing inside the Room, looking out over the "window" sill, and my mind takes me to a vision of being down on the pad deck, across the flame trench, with the RSS in the Demate position, looking back across, and seeing some lady in a polka dot dress leaning out over that sill, maybe watering her potted petunias she has there in a windowbox, and...
I dunno. I always liked these little "windows", but I never learned what they were, or why they needed them.
Maybe one day a kind and knowledgeable person will see this and email me with the answer to The Mystery.
Wouldn't that be nice?
Of course it would.
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