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Sorry for the old derail/tangent, but it was based a lot on a couple real studies, interpreted to play up the cursedness of the whole idea. You can read some descriptions and samples of those sources here.

It is (as I recall, this is going on a half decade ago now) developed for and used exclusively by lunar missions. It's too heavy to fit on anything much smaller, it only fits with the cargo lander by using some of its own propellant for ascent. Yeah, I don't think we had more details there. As you said, it was intended to be a throw-away line, mostly setting up ELVRP2.

In seriousness, Pegasus is a 5.5m super-centaur, like ACES but even moreso. With a propellant load of about 75 metric tons, that gives it a length of about 9.65 meters in the tanks, plus a bit more for the RL-10 engines. What else were you looking to know?

yah

On the "sifting through the entire thread" front, I recently got done going back through to threadmark all the actual posts, in case anyone is having that issue, but if anyone want to print a copy for their own use, then they can be my guest.

@Workable Goblin and I are okay with it as long as it's not for monetary gain. We're glad people enjoy it after so long, even if some of it is fairly rough-hewn.

That is a magnificently large stack of propellant. If I may toss a performance question back at you, how's it perform compared to M02 and H03 to the same orbit, or to escape?

Answering the SRB thrust for Carrack requires a bit of definitions. Solids can't really be throttled in-flight, but they can be throttled in the grain design, the pattern cut into the center. Since the wall tends to burn in a constant rate away from the center where the flame is, the wall's circumference at a point in the burn tends to approximate thrust. See here for a bit more. The idea was that the upper stage uses a regressive burn grain design, meaning it tapers as the burn proceeds instead of increasing, thus controlling runaway acceleration. The idea was that the grain geometry selected for the center cores and strapons for the "heavy" Carracks was intended to leave the center first stage solid burning after the strapons had burnt out and separated, at least for a little. Don't ask about the particular grain, I didn't have any really great sources at the time so that's just hidden under the "I know this is possible with enough engineering" hood. Star for the strapons or the first stage on the lighter Carracks, a moon burner or something for the second stage, and a simple circle or a moon burner for the center on Heavies, something like that?

Where'd you get the MOK module model?

No, that was pretty much the mission plan as we envisioned it. It's why Gerry Mitchell is so nervous during that mission. I'm pretty sure we mentioned the use of using thruster packages tied into the AARDV avionics for fine manuevering someplace. You can certainly see the truss ones hiding on the outboardmost of the two "X" sections just beside the center truss module in this @nixonshead render. (Note similar thruster modules leftover on most of the lab modules, too.)

Well, you successfully nerd-sniped me. I see two major drawbacks, and possibly a third depending on a question. First, as Abrecan points out, you have no abort options during the crew launch on the second lander, nor do you have any options for early return if you have to abort during the landing--you'd have to wait in lunar orbit or at L-2 until the Apollo is sent to bring you home. That's a pretty serious problem, since it means that the a far larger number of loss-of-mission incidents have risks of becoming loss-of-crew. For instance, if the Apollo fails to launch on time, the crew could run out of supplies while waiting for it even if everything else goes off as planned--the crew's life is bound to not one launch, but two--the Saturn-without-LES they ride, and the other that separately carries up their capsule. Second, I think the total payload to the surface is a bit lower. I suppose that since it looks like you're using 2xH03 and some medium-with-solids variant there's not a major surprise there, but given the mass tied up in the surface shelter, rovers, surface instruments, ascent stage, and other hardware, the added benefit of 5-10% in payload to the surface has a far larger increase in available surface stay capabilities. Third, and this may be limited more by the Kerbal parts available to you than the mission concept itself, do you only have two crew landing in this mission? You show two figures next to the lander launch and two next to the Apollo launch, with all returning on the capsule, but the ones on the APollo would never have a chance to land. If that's correct, that's a major drawback since it instantly halves your surface science crew-hours.

That array deploy was awesome! Really fun video, and I'm pleased to see that looks as bonkers in execution as it looked in my head. Doable, sure, but still I'd be nervous. Did you have forward thrusters near the radiator end of the truss, or were you flying wholly on the AARDV thrusters?

No, I just lurk this thread because content like Drakenex's really awesome recreation of Challenger and Freedom's first assembly mission blows my mind, but I know very little about mods (I played almost pure stock back when I played a lot) and thus have this tendency to lurk unless spoken about. As mentioned, this video is super awesome!

Not quite. Twin main engines staged combustion kerolox engines of roughly RS-84 design (~4.5 to 4.75 MN sea level each), and two gas gen kerolox engines in the class of the FASTRAC but designed for easy reuse instead of low-cost expendability (~200 kN each, throttle to 70%). Same basic concept, just kerolox.

I'd say we were pretty good about trying to keep to what might be possible in a practical budget. Several times we were inclined to put a finger on the scale and steer the TL in a direction we preferred rather than perhaps the most plausible path. For instance, the Saturn IC and Multibody based on it are fun rockets and feasible, but probably not great approaches at the times they're approved, and the entire period 1970-1973 or so is one giant handwave over the politics. There's alternate options that'd be more sensible, either equally capable and cost-effective per flight as Saturn IC while having lower upfront cost of development (even options that aren't Titan, something like cost-reduced volume production of Saturn IB, perhaps with boosters), or more capable for similar development cost (something like introducing a multicore 6.6m kerolox rocket right from the start, perhaps even in a version with 2xF-1A based on some of the Boeing Saturn V LRB concepts). Of course, either would involve such rewrites and butterflies it'd be a totally different timeline. The launch vehicles in the early timeline are probably the biggest issue, but there's a few other subtle ones: Space Station Freedom moves pretty freaking quick in development, as does the lunar landing program in the 90s, but on the whole I'm still proud of it.