Integration switch

[SAVORYapple]

I know that the U.S. has seemingly favored vertical integration of rockets, while the USSR has favored horizontal integration (and raising them for launch) of rockets. Of course, horizontal integration presents its own problems the larger the rocket gets, though the N1 being lifted to a vertical position does indicate to me that it can be done.

So, how do you get the U.S. to mainly use horizontal integration of launch vehicles, and the USSR to favor vertical integration of launch vehicles instead?

 

[Shevek23]

Americans using horizontal integration for Apollo, if not during the Moonshot phase than afterward, was one of many suggestions I made to e of pi and Truth is Life for Eyes Turned Skyward. Not only did I figure it would be cheaper and quicker to put together suitably redesigned Saturn 1C and Multibodies this way, my biggest concern was to both speed up the trip from the Assembly building (obviously a new horizontal assembly complex, not the old VAB) to the launch pads (because a long, spread-out crawler could go faster since its load is not a precarious vertical stack) and to minimize the risk due to strong winds and bad weather generally. Speed to the pad would not only tighten up the economics but further lower the risk of inclement weather screwing up a launch, by minimizing the time the craft was exposed to changing weather.

As with most of my suggestions, the authors disdained it. They seem to feel that horizontal integration has inherent drawbacks, beyond the crisis of finally tipping the thing up vertical at the launch site, which meant the advantages I foresaw would be chimerical and it would not be a good way to go.

 

[e of pi]

Vertical integration tends to be favored with large solids in particular, especially segmented solids like the Titan and Shuttle used. Horizontal stacking and assembly of large solids is tricky--note that every rocket to use them has been vertically assembled: Titan III and IV, Shuttle (both in the existing VAB at Canaveral and in the alternate setup at Vandenberg SLC-6), Ariane 5, the Atlas and Deltas. The Russians have always steered away from solids, and thus the horizontal assembly doesn't have the issues for them.

The advantage of horizontal assembly is that during assembly, the entire vehicle is the same height off the ground--a single set of platforms (or even just ladders) can access the entire vehicle. However, unless there are also vertical access systems at the pad, you have to tip the rocket back down to work on it--and if there are vertical access systems, the rocket is now being serviced in two orientations, which effects the human factors of the handling process. If a vehicle is processed vertically, then you do need more platforms and such, but once built there's not a tremendous difference in operations cost, and the completed vehicle only needs to be maintained in the vertical position, whether at the pad or the assembly building. Also, thanks to years of legagy, many western payloads are designed for vertical processing themselves, not designed for being held cantilevered on the front of an LV but instead supported through their long axis throughout integration and rollout and thus the rocket must still be tipped vertically for final payload processing. This is actually something SpaceX is having to deal with in their attempts to setup for bidding on DoD payloads IOTL, as I understand things.

On the whole, I'd give a slight advantage to horizontal integration, both in initial infrastructure requirements and operational benefits (at least for a traditional multi-stage tube rocket), but the presence of large solids can tip the balance in favor of vertical integration, as can existing infrastructure and traditions, and the resulting effects on the payloads being designed. If the Russians made more use of solid boosters in their program and the Americans less, you might easily see the situation reversed.

And Shevek, I'll note that I specifically addressed your points about rollout in that same thread here. If you have an issue with myself, or truth is life, I'd appreciate that you bring it up there or in a PM, rather than bringing it up passive aggressively in another thread months after the fact.

 

[SAVORYapple]

If the Russians made more use of solid boosters in their program and the Americans less, you might easily see the situation reversed.

but how can this be done? The russians, to the best of my knowledge, have never used solid fuels. Why is this?

 

[e of pi]

but how can this be done? The russians, to the best of my knowledge, have never used solid fuels. Why is this?

Boosters involve providing excess thrust on launch so a core can be heavier, or can carry a larger upper stage. Solids do excess thrust really nicely, and the US had spent a bunch of effort in the 60s developing solids of about the right size for strategic missile applications (where their always-fueled status was handy--this was the era of the Sergeant and Polaris). When we started looking for boosters, they were handy, and they got used. The Delta's Castor boosters were modified Sergeant missiles, originally developed for the Scout family. Once we'd started with solids, it was basically inertia to continue.

From what I know, the Russians under Korolev basically focused on kerosene/LOX liquid fuels in the same period, and as a result when they were looking for boosters, they had more experience with kerolox. Even their submarine-launched missiles in the 60s were hypergolic liquid rockets, and if being stuck underwater in a can with a couple hundred tons of toxic, highly explosive fuels like hydrazine and fuming red nitric acid doesn't scare you, you were well suited for life on a soviet missile sub! I'm not sure if switching those early developments is reasonable, but do it and you might put things on track to reverse the preferred integration techniques.

 

[SAVORYapple]

Ahhh…. So it’s a case of switching ballistic missile development paths. Now that you mention it, yes, it does seem like the Soviets favored hypergols and RP-1/LOX. Hell, they even superchilled their RP-1 to gain extra density of propellant. Problem is Titan II demonstrates what can happen when even a screwdriver or nut breaks loose (no pun intended, a wrench did cause a Titan II explosion). Problem is, I can’t identify a definite POD where ICBM fuel preferences can be switched.

 

[e of pi]

Ahhh…. So it’s a case of switching ballistic missile development paths.

I'm not the most knowledgeable about those very early periods, but it seems like a good starting point. However, like you say, there's no obvious PoD.

 

[Color-Copycat]

Oh, that kind of vertical/horizontal integration. I thought this was going to be about Standard Oil and monopolistic trusts.

 

[Gunnarnz]

I thought it was going to be about non-white units in the US armed forces.