wumpus

I have to question the advantage of quarantine. In hunter/gatherer society, their just isn't a sufficiently large population for human-to-human infection to be a primary disease vector. Any communicable diseases came directly from animals. It might work in a neolithic farming society, but you would need a pretty big village and nearby villages (with plenty of contact) before diseases could spread at all. Hygine should be critical, but don't be surprised if "the old ways" work better for reasons that aren't obvious to a modern type. Good luck identifying natural medicine, the shaman probably knows more than than most professors specializing in the field (especially since he can concentrate on local plants)*. In an agricultural neo-lithic society, human-to-human diseases may be possible, but you should be able to culture some penicillin (remember: it is the brown mold, not any others. And don't be surprised if you first few brown molds don't work). * Jared Diamond mentioned as an aside that modern hunter gathers appear to have PhD level botany skills when it comes to edible plants (and these were the guys/hunters knowing what anthropologists would list as "women's work"), you don't last long in the bush while passing up food.

I haven't built a "science car" since I downloaded "For Science!" (a mod that collects the science without the required "science dance"). I came to the conclusion that it was faster to simply go to Minmus and grab the science there. If you really want to unlock the tech tree, hit all the Minmus biomes (should take well under 1k delta-v, easy if you left a fuel tank in orbit that you can refuel at). Driving around with "for science" ought to unlock plenty and do it quickly, not sure if it helps to science the same biome before and after an upgrade.

BFR seems to be going along quite well. That should be able to lift whatever you want to send to Mars to Mars. I don't see any work on the habitat you need to get to Mars, nor the habitat you will live in on Mars for something like a minimum of 2.5 years. Not only that, but there have been plenty of attempts to make this type of thing: Skylab, MIR, ISS, all the other Soviet space stations, and they all fall apart roughly as fast as the Astronauts can repair them (MIR was worse). Building BFR is just one piece of the puzzle, but even cheapish heavy lift to orbit should change plenty of space calculations. I'd be curious if anybody thinks ITS will be able to fire its engines when the window opens from Mars to Earth, or if any work has started on that issue (sounds like they plan on leaving the first batch there. Not quite as bad as Mars One, but close (well, actually your odds are much better with Mars One, as they just took your money and left you on Earth. ITS still sounds like a quick way to die).

While a single F1b has a bit more thrust than 4 RS-25s (1.8Mlb vs. 1.6Mlb), that doesn't seem likely to cover the additional mass thanks to the switch from hydrolox to kerolox. A "twin boar" F1b might be a monster, and I have to wonder how effective a (possibly single) RS-25 would be as a second stage [are they even rated for ignition in vacuum?]. Sometime I'll have to load up RSS/RO and fiddle with possible SLS configurations (I suspect that it will depress me).

Throws cash? Even more than his (annual?) billion dollar checks? I guess if your competition is pulling away from a field that is fueled by defense budgets you can expect to spend a lot of money.

While we certainly aren't in a post scarcity society, we are certainly in a state where legally mandated artificial scarcity takes up much more of the economy than anything actually scarce. Compare current goods with exact knockoffs and you will quickly see the shear scale of the artificial scarcity. On the other hand, the only other attempted way to create all that IP involves central command driven socialism, which isn't always known to be better (perhaps un-command driven works in the EU). I'm convinced some sort of decentralized evolutionary-driven system would work better, but really don't have any answers.

12 year old me went to The Air Force museum in Dayton and was only mildly impressed. I was spoiled by plenty of time in the Smithsonian museums (and that was long before Udvar-Hazy [the Dulles extension] opened), although obviously Dayton had many more planes.

From a quick look at the wikipedia explanation of "gas core", I don't think there's much difference between a 1970s NTR and anything with a pebble bed (except the 1970s designed worked better and at least had the possibility of shutting down for a second burn). You also need to look at how Isp is defined. The moment you switch from hydrogen to methane, you might as well be using hydrolox. If you have any uranium in your exhaust, forget about having any Isp (you can't afford to be throwing the heavy stuff away). Note that for any temperature that doesn't melt the pebbles (why being cooled with the exhaust hydrogen), don't expect much Isp. The other issue with pebbles is avoiding a meltdown when you stop ejecting the cooling hydrogen. [back to spacex] Note that even starting a nuclear R&D program requires being on good terms with the military industrial complex (possibly civilian types in less nuclear armed nations, but that isn't a realistic option for spacex). This might take awhile and I suspect that BO has the inside track on MIC friends. Obviously this wouldn't be a problem for ULA, but they aren't going to do anything like this.

I would assume that any "rocket tube" would have to be base on kerolox (or methalox) as you are unlikely to gain any effect once the thing goes supersonic. Of course, going straight up with a TWR<1.5, this might take a few km, but I'd have to assume that you would lay pipe at a steep angle up the western face of a mountain so you would accelerate a bit faster. It would take significant TWR to run out of mountain before you went supersonic. It might make sense to use pressurized water tanks to allow high pressure to build up at much lower temperature, although I'd be curious how you eject things likely stored above the engine once you clear the tube (probably the same way rocket labs ejects spent batteries). It would also take an enormous fleet of rockets to justify this before building an air-augmented rocket. I strongly suspect that air augmented rockets are the next step, and should improve things to 20km, not just up a mountain ramp.

Unsurprisingly, the Oracle of of all things Kerbal, Scott Manley, has already had his say on this: https://www.youtube.com/watch?v=Moo5nuLWtHs As mentioned above, acceleration-limited loads (such as astronauts and passengers) require completely unfeasible gun lenghts. Either limit cargo to fuel and similar (fuel would be sufficient to justify such a thing) or have an additional stage (presumably SRB for ruggedness), and of course you will always need a circularization stage to keep anything in orbit. That said, if Musk ever builds a NY-Chicago hyperloop, that's roughly the size needed to fling passengers into orbital velocity (except that it would require adding power the entire length of the track, which is probably vastly more expensive than a standard hyperloop). As originally noted: "maintaining constant pressure" is the kicker. Traditionally, this involved carefully firing additional powder in cylinders the projectile was passing in order to maintain such pressure. If you wanted an "ice gun", I assume that it would be possible to do both this and build turbopumps pumping in liquid nitrogen that would quickly boil and push the projectile. My guess is that one look at the price for this would send you back to using artillery powder.

Presumably this is done right before ignition much a hydrogen-cooled rocket. Otherwise there doesn't appear to be anywhere that could work to radiate the heat.

The SR-71 is basically a ramjet with a compressor to get it started and to operate at slow speeds (such as when being fueled by a tanker). By the time it gets moving, there's enough air bypassing the compressor to fly the plane and I'm not even sure the compressor can survive the blast from the intake. There's also the issue of the fuel: JP-7, which is said to cost as much as "a fine scotch". No idea if this is a tech writer's, engineer's, or a general's idea of "a fine scotch", but it sounds too expensive for a fuel used in fleetwide aircraft in any case. I really don't think the engines used on the blackbird have been used anywhere else, which is doubly tragic as they are said to have "consumed most of the career" of the engineer who designed them.

My understanding is that these "compressor fans" really do most of the work in modern passenger "jets". The actual term is "high bypass turbofan" and they appear to act largely similar to a (shrouded) turboprop + jet (compressed air + fuel) engine. Just don't discount the way the bypassed compressed air (previously called "turboprop" action) adds to the jet engine similar to an air augmented rocket (or the other way around with high bypass turbofans). The result is extremely efficient up to transsonic speeds. It should also be obvious that you can't get a ramjet to work at all at slow speed (this is said to work out to ~mach .9 for ramjets designed for supersonic flight), and the efficiency improves as speed increases.

One RUD in flight. One RUD during fueling. Not sure what you are counting as the other, the cargo that failed to launch when put into the correct trajectory? The extra cargo sacrificed on an early launch that had a merlin failure (the primary cargo was delivered, but the primary customer also demanded the reserve fuel kept in reserve and not spent on delivering the extra cargo)?

Does that rely on fins/spin stablization? I've always wondered just how exact the burn lengths on parallel staging had to be, and suspected that would be a problem. It also just hit me that I think I had a water rocket that was designed to accept the "standard" water rocket as a top stage. My neighbor had a "standard" rocket, and I'm wondering if we could have put them together... This was way back in the 1970s so my memory is rather iffy. I'd be that the upper stage would drift waaaaay further off course than we'd ever expect, and our favorite launch site wasn't all that big.

The change from going from "cost plus" to "fixed, firm price" requires as much change on the customer end as the contractor. Government customers are worse than any homeowner when it comes to making changes. Gods help you if you are talking about software: the housing customer has at least been inside a house, the software customer hasn't a clue of what he is asking for. JWST (and F-35) probably take many more hours of software than mechanical and hardware design. I was in the industry when they were switching form pure mil-spec to COTS and it wasn't pretty (we also had to deal with fixed firm prices and wildly changing requirements). If the government bought a gold plated toilet seat, it is entirely likely that hidden deep in the specs there was a requirement for gold plated toilet seats (must be highly conductive and absolutely non corrosive when tested against the following acids...). This forum has plenty of threads bashing the shuttle, but I'm not aware of any proposed designs that met all the specs NASA had and could be built with 1970s technology aside from the produced shuttle. Granted, sometimes company policy to protect said company from dangerous contracts can bite back on you. I watched the company try to sell the Navy a laptop loaded with Red Hat Linux to work as an easy Unix maintenance tool. Simple? Should have been, but company policy wouldn't let you buy untested laptops for sale and by the time you got done testing the laptop, it was no longer for sale. Loop 4-6 times... And don't even think about slashing the rules that got us here. While some of the rules were likely in there to drive the cost up (I'm convinced half the nuclear regulations are there because some power executive took "not worth metering" seriously - and it was a cost plus industry when they were all enacted), most of them are there because somebody ripped off the government in some legal way without them. "Shoddy" still means unacceptable quality 150 years after it was used to make Civil War uniforms that lasted a week or two in the field (definitions of exactly what "shoddy" was varies, and probably was different for every contractor/purchase depending on the materials at hand. The only thing they can agree on is that it quickly fell apart (and typically looked good when new)).

That's a good explanation and would probably impress anyone who hasn't had the tyranny of the rocket equation hammered into them. By saying you merely need to triple your delta-v simply ignores that bit of the rocket equation that says "ln()". On the other hand, using it as an upper stage makes all kinds of sense and is one of the oldest tricks in rocketry (going back to the V2-bumper).

The space shuttle launched 135 times with 5 shuttles. Each one launched far more time than any Falcon 9 ever has and I doubt that any block 5 will get to those numbers. The Shuttle's problem wasn't "not launching enough", although that would certainly harm most programs. The shuttle's most obvious issue was the shear cost to refurbish the shuttle to launch condition. [scrubs spacex rant, replaces with more on thread topic] A better example would be the X-15, which flew 199 missions on 3 air/spacecraft. I suspect the whole budget is still classified, but it had to be less the 135 shuttle flights. All 199 missions were completed in 9 years (actually only 177 were powered, but more flights than the shuttle ever tried. Note most were speed runs with few going into space).

So for a Falcon 9 (so far the cadence champ) that is ~$100k. There are amusement park rides that do this to ~100kmh and presumably can't be much more expensive than a few years of Falcon 9 fuel. Scaling it up to 1600kmh is a bigger question. If the cost of fuel became a limiting factor (presumably a post BFR/New Armstrong ship), I'd recommend scaling this up to ~mach 1, then using a scramjet to get up to as fast as possible (NASA data shows somewhere between mach 6 and mach 10). Note: acceleration to high speed really should be done at elevation, but you might get away with a low-TWR rocket merely maintaining velocity and by the time it leaves the atmosphere it has burned enough fuel to accelerate. Using a scramjet also involves a stage separation (not cheap) and presumably recovery. Reuse of scramjets may also require de-rating that speed quite a bit. I'd recommend enough SRBs to get the TWR to 1.5 (if only for a little way) for now.

NASA/US regulations are quite strict in what is allowed to land on Mars and any other planet (no idea if this includes the Moon, they know it doesn't have life). I really don't think you could sufficiently sterilize a Telsa and put it back together. There also was no desire to build a rocket for insertion burns nor any other landing system (I think the latest round of rovers put NASA's landing success over 50%, but landing on Mars is *hard*). That Tesla probably weighs more than Curiosity, making landing almost as difficult as the upgrade from Falcon 9 to Falcon Heavy. High speed Mars impact would be the only means to "send it to Mars" even with NASA's permission. That and the whole "circularize at GSO orbit *then* burn to Mars" is painfully inefficient. If you want to go to Mars, you don't use the trajectory Falcon Heavy used. If you want to test/show off its power, you follow their path.

Can you even do a halo orbit in KSP? I suspect an iterative process where if you find yourself beating against the limits of KSP you fire up RSS, and if that doesn't work include principia (there are reasons you might not want principia in your RO/RSS stack).

Early shuttle plans assumed landing the primary booster as a Shuttle itself, but this still has a ton of problems involving mounting (and compounds all the shuttle problems of side mounts with multiple side mounts) and staging. Had spacex tried to recover the booster (starting with parachutes) even in the 1990s, I'd be surprised if they could succeed with a hoverslam. My point is that typically where NASA appears "wrong", it is typically merely that such a plan is risky and likely exorbitantly expensive if done on NASA cost schedules. It took 4 landing failures and 4 more "no attempts" during that time before Spacex finally landed a booster, I'd assume that any NASA plan would be canceled long before such success. The more I look at all the constraints the Shuttle had to fulfill, the more I think it was a miracle of engineering to cover all those points. I really don't think a "flyable first stage" would have worked as well as the end result (assuming all the rest of the requirements still need to be met). The other example (fancy gravity tricks) showed NASA being wrong in much the same ways the "NASA is ignoring my brilliant plan that works in KSP" conspiracy theorists insist it is wrong: sometimes it happens, but don't expect to come up with many more examples.

The earliest flights were completely automatic (Vostok, Mercury flights were designed automatic and obviously did so with the earliest primate crew) so that puts a huge damper on available means to discover prograde (GPS, stars, etc). Gyroscopes were obviously available, and I'd hope that a means of tracking the Sun was possible (I'd expect liftoff to coincide with enough time so that the Sun was visible until orbital insertion) for gyroscopic correction. Also if the Sun was visible, certainly the Earth was as well (Astronauts could obviously see the Earth at night, but I'd wonder about 1950s sensors). Astronauts in the Apollo missions did check the stars while traveling to the Moon and updating the computers. There's some question as to whether or not this was necessary or an improvement (which may have been pure propaganda, telling the Soviets that US missiles were uncannily accurate). https://www.youtube.com/watch?v=X2J-5QJC1qc [Vintage space discusses the need to wear eyepatches thanks to this procedure].

Everytime? For high visibility projects such as the Shuttle and SLS, many of the decisions come from Congress and outside of NASA which leads to decision that have very little with "doing it right". Googling "NASA SSTO" gives 60k+ hits. While many of them have nothing to do with NASA, there are pockets in NASA that simply won't give up on an obviously broken plan. On the other hand, the converse, that there exists an obvious solution that NASA is ignoring is almost certainly wrong. I'd go so far as to say the exceptions prove the rule, such as Spacex's example that saving the first stage booster is key (reusing the orbiter might be gravy, but the first stage is key) is *hard* and provably non-obvious. There was also pushback from NASA on using more advanced gravity tricks than "slingshots" as they wanted to stay "in the big rocket business" (this is harder to justify, and shows that NASA isn't a simple monolithic supply of excellence. This might also be pushing all those stupid SSTO plans).

Considering the "runway" is much worse to launch/land aircraft on than the unimproved grass beside it, I'm not sure what you were expecting. The "level 0" runway comes pre-destroyed. Note that if you plan on landing on the grass, you probably want to make an aircraft capable of making it up the lip of the "runway" so you aren't charged fees to return to KSC.