Workable Goblin

Space launches aren't usually aimed at other countries, which suborbital transports usually will be. Anyway, this is something that people in the field have said is a challenge, so I believe them. Not really. A Mars base could do almost anything that the ISS could do (aside from that dealing with microgravity--but then, it would be able to do research in partial gravity, which has not been studied at all...), plus it could do a lot of planetary science, obviously. So it would clearly be more scientifically productive. You would get more science, however you want to define that, out for every dollar you put in, if the costs were comparable. Absolutely untrue. Humans might not be particularly efficient at, say, astronomical observations, but they're much better than machines in some other fields, particularly planetary science. If you compare the Soviet Lunas to the Apollos, the only actual example of competition, the latter were clearly far more cost effective--they cost something like ten to a hundred times as much (on the order of $100 billion versus on the order of $1-10 billion) but returned a thousand times more samples (380 kilograms versus 326 grams), those samples were recovered from multiple locations (the Soviet sample return spacecraft could only return samples from one position), they emplaced five ALSEP surface science stations that lasted until 1977 (the Soviets landed no such long-term experiments), they traveled farther altogether than both Lunokhods put together, they traveled faster than either Lunokhod (sure, Lunokhod 2 traveled 39 kilometers to about 36 on Apollo 17, but the latter did it in 3 days, while the former took five months), and so on and so forth. The Apollo missions cost a lot more upfront, sure, but they were so much more scientifically productive that they were cheaper for the science than the Luna missions were. Now, I know you're going to come back, "Ah, that's crappy 1960s Soviet-era technology, modern tech would be so much better!" Well...no. Relevantly, take a look at Mars sample return. During the last decadal survey, JPL proposed (warning, PDF) an ascent vehicle design that would be able to lift 5 kilograms of payload into orbit, including a sample containment device. The decadal survey itself estimated that the caching rover (for finding the samples) would cost $2.5 billion (if you just dropped the ESA involvement, which was more or less what happened...), although the actual implementation of that (Mars 2020) is currently running at about $2.1 billion. Considering that the MAV and sample return orbiter are just as important and less technically mature, I doubt either would cost much less, so optimistically you're looking at a cost of at least $6 billion or so for the full mission. Now, by contrast, consider a human mission. Most realistic estimates put the cost of building up a humans to Mars capability in the range $100 billion to $1 trillion, and most mission plans that I've seen envision returning about a metric ton of samples. Assuming that the cost of the first mission is at the very high end of that range, you end up paying almost the same for each kilogram of samples--about a billion dollars--as you did with the robotic mission...and if the cost of the robotic mission is higher or the cost of the human mission is lower or both, the humans come out ahead. And that's not mentioning the fact that humans don't need to be babied by Mission Control as much as rovers, so they're likely going to be able to travel farther, collect a more diverse set of samples, and so on than the robots, so you would get more out of your billion dollars per kilogram than with the robots. The main reason why robots are in fact better than people is that it's practically impossible to get anyone to spend a trillion dollars on putting people on Mars, whereas it's only very difficult to get them to spend six billion on putting robots on Mars. If it only cost six billion to do the human mission, somehow, then you would very definitely rather have the humans, and they would very definitely be more efficient than robots. Anyway, this is all rather beside the point of this thread, I believe.

Actually, they almost certainly wouldn't. Yes, the Antarctic Treaty exists, but Antarctica is a very harsh environment which is extremely difficult and expensive to extract resources from, to the point where it is not economically viable. Just look at the trouble Shell has had trying to do offshore drilling in the Arctic, and remember that the Arctic is easier than the Antarctic--there are permanent inhabitants, for one, there are fairly well-established transport routes, they actually do on-shore drilling there so they have a base of experienced people, and so on--yet they just couldn't make it work out, and ended up spending billions of dollars and writing off billions more in assets once they gave up. Resource extraction from Antarctica is not viable because of the economics, not the Treaty, so countries are only establishing scientific stations so that if it does become viable they have a shot at making some money from it, not because they're just waiting for the Treaty to expire so they can start taking that sweet Antarctic oil. But you could say the same about Mars. Currently, extracting resources (or performing any other economic activity) on Mars doesn't make any sense. There's always the possibility that something might emerge that would change that, though, so there's an incentive to stake a claim (Outer Space Treaty or no), just in case and, hey, Mars bases do have some scientific and propaganda value in the shorter term, just like Antarctic bases. Right now, even that would cost a tremendous amount of money, so no one has done it (or even staked a claim on the Moon, which is obviously much easier in a lot of ways). If costs can come down, though...well, as I said, if you could bring them down to space station levels, then it becomes conceivable. A Mars base would be much more scientifically useful than a space station...

There would also be the issue that it would look like an ICBM launch (because, well, it pretty much would be an ICBM launch. Only the missile carries people instead of bombs). Setting up systems to make sure that no one accidentally starts a nuclear war because they mistook your transpacific hop for a nuclear attack would be...interesting.

No, it's highly relevant, because it's basically the only form of colonization that is actually happening in today's world. And it's not that small a number of people, nor is it really a "few exceptions" case--there are Antarctic bases from thirty countries, and they host a thousand or so people year round. That's quite comparable to the early phases of any historical case of colonization--Plymouth only had about a hundred people to start with for instance--and there have been children (a fair number, actually) born in Antarctica. It's hardly something to dismiss out of hand. There is a reason why I emphasized the if. Really. I am pretty aware of the economics of space flight. Er, ever heard of the ISS? Or Tiangong (1 or 2)? I thought it was pretty obvious that I was talking about governments, given that I specifically mentioned multiple government stations when talking about Antarctica and I was discussing a colonization model which obviously depends on the government (more so than usual, anyway) to function at all. The point was that if you could really build a Mars base for about the cost of a space station, the United States and China, at least, probably would, and the ESA and Japan might, either by themselves or together with the United States. India or Russia might or might not join in, they have smaller budgets than the other four. And there might be others that would ride on coattails. So Mars would become like Antarctica, and have permanent settlements (but not inhabitants).

That's not actually true anymore, sort of. Since about 1950, a third "colonization" model has sprung up--the scientific outpost, a habitat which is inhabited permanently but by rotating crews to conduct some kind of scientific research, like in Antarctica or with space stations. Governments have, collectively, spent billions of dollars on these over a few decades even discounting the ISS (the US alone spends about $300 million per year on Antarctica, and there are a lot of countries with Antarctic bases), so clearly they're willing to dump money into them "just because". Admittedly, in Antartica there are shades of the second point as well--Australian bases in the AAT, Chilean and Argentinean bases in their claims, and so on--and we know there is stuff there that could be mined. But we know the same thing about Mars, too, and it makes about as much sense to set up a Mars base to do research and establish a seat at the table if something that could make doing stuff on Mars profitable emerges as it does to establish an Antarctic base to do research and establish a seat at the table for Treaty revisions if something that could make doing stuff in Antarctica profitable emerges. At least, if the cost is reasonable, which if Elon can get his cost figures to where he wants would pretty much be the case--the delivery of payload to the Martian surface would have to cost less than about $2,000 per kilogram for a ticket to cost $200,000, which is about the same as what it costs to deliver payload to orbit today, or less. Thus, it would cost about the same or less to operate a Mars base as to operate a space station even with minimal ISRU and, well, there are a couple of groups doing space stations. Of course, the trouble is that this isn't what most people think of when they say "colonization". Nor is the other probable model of space "colonization," which is oil rig-like asteroid mines (which would also be much more plausible if the ITS works out), because in both cases you just have people traveling out somewhere for a limited time before returning to Earth, and making no attempt to permanently inhabit the area. But it is, nevertheless, a method of colonizing an area, and certainly some kind of a step into space.

I specifically mentioned that I am not on 1.2, since that doesn't work on the latest version of macOS, so I don't have the science container. As I lamented, since it's a pretty awesome part! Also, I know how to play the game (I have, uh, 483 hours in it...); I just hate having science data I could have collected but didn't lying around, so it's extremely difficult for me to not grind that out (same as in every other game). Anyway, I changed my mind and decided to grind Kerbin/KSC science later, now that I've gotten most of the most accessible sources. Instead, I have a probe that just flew by the Mun and is current on its way to Minmus en route to solar orbit. I've got another probe getting ready for Munar orbit, and a bunch of satellite contracts just waiting for action. And a new capsule that can do rendezvous and docking...

I started a new career with an eye towards 1.2 (which I can't play right now owing to the issue with Sierra), after thinking about it a lot recently. So far I've gone through most of the really early game and have my second orbital flight going on. I just unlocked Aviation, so I've been grinding through KSC science with my new science plane, and I'm going to start working on Kerbin science once I've wrapped that up (mostly just need to eke out the last drops of Materials/Goo science now). Once that's done I'll start thinking about the Mun and Minmus... The thing I miss most from 1.2 is the experiment capsule (and the ordering of science parts). It's surprisingly annoying to have to EVA or return experiments to get full value.

Well, I dunno about other people, but sometimes I'll start playing and get distracted build airplanes and rovers and things like that, which obviously have some trouble getting off of Kerbin, or I'll start playing a more spaceflight-oriented game but have to quit for some reason or another and then not get back to it for a long time, so when I do get back I want to start over. And so I play a lot (in total) but don't get to the Mun.

Heck I've been playing over 400, and I've never gotten to the Mun. Well, okay, that's not true, but it's approximately true...0 and, I think, five or so are almost the same...

It wasn't. It was being thrown around as an example of whether or not repairing at all was economical.

I, too, am noodling around in career with pre-1.2 while planning a proper career for the final version (with mods), and this is...kind of the exact opposite of my experience? I designed a launch vehicle which was basically identical to the second vehicle you describe, except with a liquid upper stage replacing the Hammer and Thumper, and it was awful. It basically did whatever it wanted while taking off until you managed to get through the first and second stages (that is, the four Thumpers and the two Thumpers), by which point it had usually lofted you high enough that you had time to line up for the final solid burn and final orbital injection on the liquid stage. Not to mention it was far too heavy to launch off of a T1 launch pad, so you had to upgrade that before you could do anything with it. Then I designed another all-liquid vehicle which works a lot better. It's just a few TL-400s stacked on top of each other (I don't have the TL-800 yet, haven't got the science for it; rushed probes...) with a Swivel as a boost engine and a second stage that's a TL-200 and TL-100 plus an LV-909. It'll pretty reliably lift a capsule or probe to LKO, and I'm pretty sure it could do a Munar or Minmus flyby mission with a light probe (certainly it could with a few boosters). It's not noodly or wriggly at all.

@NathanKell: Thanks, that solved the VAB/SPH issues! The main menu is still a bit squirrely, but that doesn't matter as much for obvious reasons...

I saw this thread today and said, "Hey, it's been a while since I knocked together an air-breathing SSTO, I should do that again!" So I put one together in about five minutes, took it up, flew it around the world, and landed back on the runway. Then I said..."I should do that again and take pictures!" So...I did. Presenting the QS-1 Needletail light SSTO (intended mainly for very long range Kerbin survey work, maybe applicable to Laythe too). Made in 1.2 prerelease, no mods of course. The Needletail lined up on the runway, ready to take off. Accelerating upward. It took me a while to figure out how to coax it upwards in speed, it wasn't quite as easy as with the first version. By this point, I had figured out how to make it get up and go... ...so I went until my apoapsis hit 75 km. Did a bit of closed-cycle burning once I hit about Mach 3 and 22,000 meters. Once I hit the top of the arc I lit up the engines again and burned into a nice orbit... Apoapsis of 83 km... ...periapsis of 75. Then I had to stay in orbit for a while, since as you might have noticed it was night at the KSC and I wasn't going to try landing in that. In the meantime... ...I got some glamor shots of the plane lit up... ...including one flying over KSC. Well, it's daytime now, so I made a little deorbit burn and waved goodbye to the Mun as I hit the atmosphere... ...and start a shallow glide for KSC. Some parts get a little toasty as I descend below 50,000 meters, but none of them come even close to overheating. I keep gliding until I have KSC in sight... ...then turn the engine back on as I fall towards Mach 1. I have to admit that getting to the runway was pretty tricky and I was too busy to take any screenshots until I touched down. Actually, that was my third touchdown. The first two times I bounced (did I mention I was busy? Also that the landing wasn't perfect?). At least I managed to stay on the runway... (I did slide off, but I managed to get back on! That counts as a runway landing, right?) I just noticed this, but I never opened up that cargo bay for inspection. Didn't cross my mind because it was empty, honest.

You're missing my point. Yes, they might happen to look similar. Yes, they might happen to have similarly-sized mirrors. Yes, they might even happen to have a lot of the same guts. That doesn't actually mean that they are similar, because the missions they're meant to fulfill are quite different and tend to evolve differently. Well, it's funny you should mention Eyes, honestly... That was what I meant by mass production as well. It does not work for scientific satellites because it's completely missing the point of scientific satellites and the whole structure of science, which is borne out by the utter flaming failure of the concept the few time it's been tried (as I mentioned, the Planetary Observers and Mariner Mark II programs were supposed to be exactly this, and led to one of the most expensive planetary science missions ever launched, Cassini, and the expensive and failed Mars Observer). Science builds on itself, so you never want to just keep building the same vehicle again and again once you've launched it once. You want to change it and alter it to meet new demands and new goals. Once you start looking, really looking, at what using new instruments means, it's obvious that for all but relatively minor changes you end up needing a whole new vehicle, not just a tweaked version of the old one. Which, as I've said, plunges you back into the world of new programs and the resulting costs and delays. There's also the very important fact that while Congress (or the Politburo, or whoever) is probably willing to pay for a few spy satellites at a time, so they can be built in batches, they are probably not willing to pay for a few telescopes at a time. And if you're waiting on each launch to find out whether you're building the next telescope, you're really not going to be seeing any benefits relative to...well, waiting on each launch to figure out what the next telescope is going to be. As I have pointed out twice now, even if you use the $1.5 billion figure the cost of launching a service mission was no greater than launching a new telescope, and quite possibly less depending on how well development went. There are plenty of cases where "simply" "reusing" existing designs for a new missions turns out to blow up in people's faces and demand far more money than a new whatever would, and it's quite probable in such a case as this where astronomers would be demanding quite significant changes to continue supporting your continuing multi-billion dollar new telescope program.

I play exclusively on Macs, and it's worked fine for me since 1.0.2 or some such. Right now 1.2 is a little funky, there's a weird momentary graphical glitch when loading the VAB (and I assume the SPH, but I haven't tried it yet) and the menu and VAB screens lag pretty noticeably for me (which didn't happen with 1.1.3), but once you get into the actual game everything works fine. 1.1.3 definitely works fine on Macs, given that you have sufficient horsepower. Don't expect silky-smooth gameplay on a MacBook displaying on a 4K external monitor, but for recent iMacs, at least, you ought to be fine.

No, there are a series of possible counterfactuals here: NASA builds Shuttle, NASA repairs Hubble. Reality, in other words. NASA builds Shuttle, NASA does not repair Hubble. NASA launches Hubble replacement later, on Shuttle. NASA does not build Shuttle, NASA repairs Hubble. NASA does not build Shuttle, NASA does not repair Hubble. NASA launches Hubble replacement later, on a different LV. It is perfectly possible that NASA builds Shuttle, launches Hubble on Shuttle, and then doesn't repair Hubble. It would take some subtle work to justify, but it is possible. And going by what you actually said, which is that NASA doesn't repair Hubble, not NASA doesn't build Shuttle, you were talking about (2). Anyway, as I pointed out the conclusion is the same if you compare (1) to (4) as if you compare (1) to (2); servicing Hubble was not more expensive than building new telescopes. You cannot extrapolate from spy satellites to astronomical telescopes, they are entirely different beasts even if they happen to share a form factor and have similar optical trains. The key problem is that science marches on. That is, every observatory resolves some astronomical questions and opens up new ones. For example, in the 1970s, when Hubble was designed, no one was considering extrasolar planets and so Hubble was not designed with them as a factor, but in the 1990s and 2000s, when James Webb was, they were one of the hottest topics in astronomy (and still are), so they had a major impact on the telescope's design. To address these new questions, new instruments and possibly different designs are needed, which in turn means that you're not just building a copy of an old telescope with a few tweaks, but a new telescope, meaning that you've gone right back to the beginning. And astronomers are a pretty well-organized and influential political community, for a bunch of scientists, so they're going to push for new telescopes and probably get them (they may regret getting them, but they will probably get them). None of this is true of spy satellites, the basic questions that a spy satellite is supposed to answer (where are the missiles? Where are the tanks? Are the tanks getting ready to roll?) are much more constant than astronomical questions so the only reason to change them up is technical advances. By contrast, every observatory is asking new questions from the one before it, and that almost inevitably means it will have a new design. For that matter, all kinds of scientific satellites have the same basic issue that makes proposals to "mass produce" them unrealistic and absurd. It's extremely unusual to see serial production of identical scientific satellites in the modern world, with the marginal exception of weather satellites (for the obvious reason that you need more than one to see very much of the world reliably). The only cases tend to involve launch failures (as with OCO2), in which case obviously science can't march on. In any case where it is desirable to include new instruments or alter existing ones, it tends to happen--and the result is that savings are very marginal or non-existent. In the similar (in terms of costs, and scientific control) planetary science program, the Mars 2020 rover, which is a copy of Curiosity with new instruments, is estimated to only save about $400 million relative to the cost of Curiosity, whereas the 1980s Planetary Observer/Mariner Mark II program--an effort by NASA to do precisely what you're suggesting in planetary science by designing a common probe chassis and reusing it in a bunch of missions--was a complete and miserable failure, mostly because a one-size-fits-all chassis fit absolutely nothing and had to be customized to each mission anyway. Anyway, taking the 2 billion a pop cost and 8-9 year construction time at face value you're...still spending just as much on building new telescopes as you would have repairing Hubble, and you're spending more time on each new telescope than they actually did on the repairs. Yay?

No, in this case it's precisely the opposite. Your claim was that it would have made more economic sense to throw away Hubble and build a new one than to repair it. You didn't specify, "In a counterfactual where NASA didn't develop the Space Shuttle and therefore couldn't repair it," so it's totally fair to assume that in either case the Space Shuttle does in fact exist and NASA has in fact spent the money needed to develop it and all the various fixed costs associated with it. In that case, the proper comparison is between the costs that NASA actually did incur as a result of launching the servicing missions--that is, the marginal costs of launching the servicing missions--and the costs of building and launching a new telescope, that is the marginal costs of that option. Anyway, even if you take the fully-burdened $1.5 billion (in 2011 dollars) cost of launching a shuttle mission to Hubble and add the additional billion to the other costs of the servicing mission, you get $2.2 billion (again, in 2011 dollars). The cost of developing Chandra exclusive the launch was $1.65 billion in 2000 dollars, or $2.15 billion in 2011 dollars (inflated with CPI, which isn't really right but is still better than using 2000 dollars); the cost of James Webb exclusive the launch was estimated to be $8.6 billion (in 2011 dollars); and the cost of Hubble itself exclusive the launch was $4.2 billion (see page 10), also in 2011 dollars. I couldn't find equally reliable costing data for Compton, unfortunately, just some websites saying it cost $617 million without specifying what year or breaking it down into development, launch, and operations. Each of these three observatories also took about twenty years to go from initial proposal to launch (projected launch in the case of James Webb, of course). So for observatories comparable to Hubble, that is big observatories that require Shuttle or Titan or similarly large launch vehicles, the cost of developing the observatory--that is, everything except launching (and operating)--is, in fact, comparable to the cost of launching a servicing mission, even using the fully burdened launch cost, and can be much larger. In the best case, Chandra, a free launch would have allowed the overall mission to cost about the same amount as one servicing mission, with fully burdened launch costs. In other words, it would still at best cost about the same to build and launch a new telescope as to service Hubble, not less--and with the rather obvious and considerable risk that your new telescope suffers a launch failure and goes precisely nowhere. At least if a servicing mission fails, the telescope is still there and you can keep using it for a time, perhaps long enough to try to service it again. In the best case, Chandra-like development costs, maybe (though it would have taken 40 or 50 years to actually launch "a few" Hubble replacements, so it's still questionably advantageous). In the worst case, James Webb-like costs, absolutely not. You'd be paying just as much to build the new telescope as you would have to launch service missions...several service missions, in fact. Robots can require repairs, too... And thank goodness for that, actually. I used to play BARIS (because, er, KSP didn't exist...), and that has a miserably punishing failure system. I prefer being punished for design errors not random component failures, thank you very much.

That's not actually true, in two ways. First and least interestingly, there were a number of satellite servicing missions before Hubble was even launched; SolarMax, Palapa B2, Westar 6, Syncom IV-3, and Intelsat 603 all had Shuttle missions partially or entirely dedicated to dealing with their malfunctions, all of which were at least partially successful. Of course, except for Intelsat 603 all of those were pre-Challenger missions, so they don't say much about the economics, but they happened. Second, it just isn't true that it would have been cheaper to throw Hubble away and send a new one. The overall Hubble program, including servicing missions, has cost about $10 billion to date. $4 billion of that was for construction and launch, which means each service mission averaged around $1 billion in marginal costs (including instruments, launch, extra operations time, and so on). Major observatories like Hubble tend to take fifteen to twenty years to develop and launch, and I can't find any that cost less than $3 billion (Chandra). The one telescope that was actually developed as a Hubble replacement, James Webb, has had infamous budgetary overruns and is currently projected to cost around $9 billion for construction, launch, and five years of operations, not significantly less than Hubble itself with servicing. It wasn't possible to just build and launch a second Hubble in 1991, and anyway it wouldn't have been desirable, since astronomy and technology had moved on since the design was finalized in the 1970s and the astronomers would inevitably have wanted new instruments. Assuming that they would just build a second Hubble and send it up on the next shuttle (which a lot of people who say this seem to think) is extremely unrealistic; launching clones of particular vehicles has been very rare since the 1970s due to increasing costs and build times. (And yes, all those are real dollars and hence comparable) For the case under consideration (servicing GEO power satellites), all of that is quite reasonably economical. Such satellites are much too big to build on the ground and launch into space, so they're going to need assembly stations in orbit to put them together. Such stations will, by definition, have a lot of satellite parts on board--spares, in other words. Such satellites are in fact of marginal economic viability for any reasonable (and many unreasonable) reductions in launch costs from Earth, so they very nearly require space-based manufacturing to make sense. In that case, obviously the spare parts are made in space, so it would likely be more costly to fly them down to Earth to supply Earth-based servicing missions. Since such satellites require infrastructure that makes moving people and supplies through considerable delta-Vs cheap and easy, it wouldn't be much trouble to ship them around for repair missions, either. And as far as propellant boil-off...well, use storable propellants. Sure, they're toxic, but that just means you have to isolate them from crew quarters. Such services might also come along with other roles. For example, the spacecraft used to ship crews and parts up to satellites that need repairing might also launch satellites and beyond Earth orbit missions, or the station might also be a propellant depot that stores enough fuel and oxidizer to ship anything to anywhere anyway.

It really isn't. Scale is not just a minor detail here, it's completely dominant. A good comparison is computers on Earth. Suppose you have a cheap smartphone, something that costs $100 or less. If it breaks it probably makes more sense for you to get a new one than to try to repair it, just because it would cost nearly as much to fix as it did for you to buy it in the first place. The same is true of cheap tablets, cheap laptops, and other cheap consumer computers. Now compare to someone who has a big, dedicated cluster or mainframe or similarly high-powered computers. In that case, fixing the computer if it breaks totally makes sense; that kind of hardware costs millions of dollars and months or years to put together, and often does millions of dollars worth of "work" every day (whether that be scientific computations or processing financial transactions or any other computationally demanding task), whereas it costs much less and takes much less time to repair it. Many such computers even have dedicated staff on hand who can fix problems as they arise, which would be obviously silly for even very expensive consumer gear. Obviously different conditions apply, such that saying "it's exactly the same, computer service!" is completely wrong and misleading. More or less is true of satellites today versus the kind of giant solar power satellite that linuxgurugamer is talking about. Satellites today aren't cheap, exactly, but they have a construction and launch cost which is comparable to the cost of servicing, and it would probably take about as long to put together a servicing mission as to build and launch a new satellite, nowadays. So it doesn't make any economical sense to service satellites. A huge solar power satellite, though, would be enormously costly and require a long time to build, not to mention that there's physically less room available for such satellites than for modern communications satellites (and since they want to live at GEO, space is actually a concern). When combined with the fact that building such satellites economically would necessarily require a large, costly infrastructure that would make it cheaper to travel to GEO and LEO in the first place, it it much more likely that it would make sense to repair such a satellite than to repair modern-day satellites, just as it makes more sense for big companies to repair the giant computers they use for processing-intensive tasks than for consumers to repair their tablets and smartphones and laptops and so on, perhaps even to the point where it makes sense to permanently station maintenance staff at the satellite in case of any problems.

Now these I can answer right off the top of my head. The S-IE is roughly (note the word) the same size as the S-IB, that is the Saturn IB's first stage; it works out that one F-1A has roughly the same sea-level thrust as eight H-1s, so the stages end up being roughly the same size (this is why we went with this even though using the F-1A and introducing a new lower stage were extremely unlikely in reality). The F-1A does have a rather higher ISP, though, so you end up with more payload. Now, you ask about the two versions of the Saturn IC. That vehicle is replaced in the 1980s, in our timeline, by a modified version called the Saturn Multibody which incorporates a number of design revisions to further increase payload, including the ability to add boosters, both solids (which are shown in the second image you link) and liquid cores (which are shown in both). The positioning of the words in the first image makes it appear that the Saturn IC designation might encompass both single-core boosters, but in fact it only describes the original version, which might be called the 'all-white' version (as we've been discussing). The upper stages on the vehicles are all versions of the S-IVB, though modified to use a J-2S (also enabling more payload). The multi-core versions of the Multibody also have the option to use a new upper stage called the S-IVC, which is the same diameter as the S-IVB (hence, as Nathan notes, could use the same tooling) but stretched to 'fill the thrust' and equipped with a second J-2S for increased thrust/weight ratio. This provides a major payload boost compared to using the S-IVB on such a large lower stage as the multi-core versions possess. There are also two prominent optional third stages; all versions may be equipped with what is essentially a Centaur-G (in terms of size) for beyond-Earth-orbit payloads, while the heavier versions of the multi body might be equipped with a Pegasus stage, which is essentially a new version of the S-IV or a '90s version of ACES, depending on your perspective, and used for large lunar payloads. Hypothetically it would probably be possible to build a four-stage vehicle using these two upper stages (or beyond, if you threw in solid kick stages), but this has not actually been done and would require a new fairing to actually fit payloads on the rocket.

Our main thought, from what I recall, was that NASA would be discarding the optical tracking system that they used during Apollo by the late 1970s or early 1980s (as they historically did) and then stop painting the tanks to save weight (as they historically did). I don't think either of us thought about the foam or lack of on the kerosene tank, so if that shouldn't be cryo orange that's probably an error on our parts. @eofpi might remember better, though.

Ah, I was talking about MechJeb's Spaceplane Guidance autoland 'feature.' Does a great job of lining up, but it really, really, really wants to touch down at the runway threshold, which is no good. Especially because it thinks the runway threshold is underground due to KSC's facilities being elevated above ground level. Oh, and it will ignore terrain if it happens to get in the way of the glideslope. (It's very dangerous to use this 'feature' with the island runway) Like I said, great at lining up, but requires a firm hand on the stick or it will crash straight into the ground.

I am. Sort of. Pilot Assistant does a pretty good job of flying the things, but you still have to know your flight profiles to tell it what to do. (Also, I fid MechJeb does a terrible job of landing planes; it always wants to plow them into the runway threshold. You have to really keep a firm hand on it to keep it from crashing every single time)

Did you use a parachute? Amusingly, falling too slowly is a problem on real gas giant probe proposals (though for rather different reasons, of course; there the goal is to get to a certain depth before the relay mothership goes over the horizon), and to deal with this they plan on cutting the parachute at a certain point. I would expect on Jool that you could simply get away with not having a parachute at all...that would obviously make it take less time to reach the depths. Though it would still take a while.

@Speeding Mullet, I like it, looks like the Shuttle II designs JSC was working on in the early '90s. Very similar crew compartment design.