wumpus

Well they could blow it up and say "oops, it exploded". It might cause a budget hiccup, but not so much. The point of my post was that there are clear legal reasons that NASA doesn't have any say over how budgets are spent (at least in buckets of $100,000,000). Congresscritters will hear the squealing the moment the properly connected don't get their pork.

Much like the original plan to use parachutes to return rockets to Earth (and then switched to the less obvious retro-rocket), Space-x originally planned on using LH2/LO2 for the MCT. For whatever reason (I'd guess boiloff, but LH2 isn't friendly stuff) they gave up and moved on to methane. To be honest, I doubt we will be able to draw any conclusions from this unless Space-x either switches again (and we learn that methane wasn't the right choice) or builds a third engine using methane (thus proving they really liked it). Some issues: * First stage is too big if you stick to all LH2/LO2. Has anybody ever made a first stage *pure* LH2/O2? The shuttle left the pad with H2, but was mostly carried at first by those SRBs. It might just be too big to make. Everybody that I can think of that used LH2 also used something else as well. Space-x likes single fuel types: note that they might not think of the shuttle the same way. SRBs are simply transported (full, heavy, and dangerous) to the launchpad. Once they are there they don't have to bother with them any more. I don't think space-x ever considered SRBs, but it would be interesting to know why. * Boiloff. A huge issue if you plan on leaving your craft in Earth orbit while its under construction. Not that LO2 and LCH4 don't have boiloff issues, but LH2 has the most of any material. Three parasols (light/heat shields) should be enough to block the solar heating. Expect another shield for earthshine. Don't ask what sort of insulation effect combination have (Webb will be at L2 and won't have significant earthshine). Note that even LH2 leaks (through all known materials) and will require a few percent more fuel to cover losses, although I doubt this covers the Isp advantage (but Isp, plus bioff, plus big-honkin-extra-size...) * cryogenics: I wonder if they started the deepcryo program before or after switching fuels. They might not have been willing to bet the farm on LH2 cryogenics but might have made a different decision now (and find it too late to profitably change).

How many times do you hear the term "weightless" with respect to orbiting bodies? And how many people know just how "close" the ISS is (you might know gravity decays at an inverse square, and think it just decayed until you are blatantly shown how close LEO is to Earth). Sure, most KSP players likely already knew the difference between hitting space (yay!) and staying in orbit. But did you learn a lot more (like Randal Monroe)? I honestly thought that "escape velocity" meant "an infinite distance from Earth" (and to be honest, Scott Manley said a similar thing in a early KSP video. Of course that was before "the Sun"/Kerbol was included so may have been right on a technicality). First time out of Kerbin SOI, "oh look. Looks like my 'infinite distance' maxes out at 2AU".

Can they just make a bunch of power point slides, build a facade around a "real" rocket (even space is optional, it just has to go up, look impressive, and come down in the Atlantic out of site)? And spend the money on things NASA needs? Or to be less obvious, perhaps giving "priority" to multi-use technologies desperately needed elsewhere (*of course* this is criminal in government contracting. Don't think it hasn't been tried plenty of times since France was financing the US government). It isn't even their call to cancel it. I think it was a SCOTUS decision in the Nixon administration that said the government is required to spend all money congress earmarks for it (that was a political decision, not a technical one, but as far as the Constitution is concerned congress's political concerns are the law).

Unless you can make multi-tesla magnets with only helium*, you are going to scatter neutrons into matter that is going to get radioactive. At some point we will have to get over the idea that diffusing pollution is always better than concentrating pollution (is it better to litter than throw you trash in a landfill?). While I'm not against chasing fusion, we really need to do more with fission and less with coal. * for Tokomak-style reactors. The national ignition facility laser confinement might be able to pull this off.

Space-X also gets certain NRE advantages in having a single type of engine (in vacuum and non-vacuum models). Using a straight F-1 has issues similar to using an RD-180 design straight out of the 1970s (as opposed to whatever they are using now), it is built assuming 1960s parts and skills. My understanding is that NASA recently built an F-1 by using (ultra-high-tech metal additive) 3d printing, as the welding costs (and inspection) required would have been prohibitive. Don't underestimate engine-out issues. If you have any hope of manned launches or plan on lifting vehicles that cost more than the launch costs (i.e. nearly all the existing market) you will need extreme reliability. Allowing a single engine-out changes your reliability from roughly the reliability of the engine to the reliability of the engine squared (unless, of course a bracket fails in your fuel/oxidizer tank).

Unfortunately, the only way the shuttle ever made sense was to smuggle that one very large satellite back down to the ground. We also know that neither actually happened, because such a launch had to happen at Vandenburg (which never launched a shuttle. And there is simply no way to keep a shuttle launch secret. This is why I don't understand your entire premise. This threads has a bunch of holes: 1. You assume that the shuttle's cargo bay could be smaller and cargo could use fairings like every other rocket. At this point the biggest design failure of the shuttle disappears and of course you could build a better vehicle. The shuttle was a remarkable craft assuming you needed to schlep 5-7 astronauts and 100Tons of orbiter every mission whether you needed them or not. Congress, DoD, and NASA liked this idea, thus the shuttle. 2. Assuming you can vertically land a Saturn, and/or you can reuse an F-1 engine. NASA considered engine re-use from Mercury and abandoned it every time up until the Shuttle. The SSME engines were designed to be reusable (and used non-sooty fuel) and still were more expensive to refurbish than to launch a single use rocket (presumably without the 100T returning penalty). You would need to redesign the entire engine to throttle (Saturn emulated "throttling" by turning off an engine) and somehow create the autonomous computers out of 1970s tech (hint, plenty of computers were built using discrete transistors at the time). 3. If you want to go for re-use, the DC-3 appeared the way to go. Get rid of the pointless specs that the Apollo-Shuttle needs, and the DC-3 is suddenly viable. The only real question is why the DC-3 hauls jet engines into space while the flown shuttle didn't need them (hopefully they could have done without them and had more cargo room). 4. If Congress/DoD/NASA are willing to ditch the cargo bay (and make the entire orbiter 30T), you open some new possibilities for the actual shuttle design. An "regular" shuttle (as designed, but considerably scaled down to 30T launches), and a "heavy" shuttle, with two more (Buran-style) SRBs and presumably a somewhat larger fuel tank (plus another 30-50T inside a fairing). Note that this gives you *real* re-use (wildly easier than anything made out of Apollo parts, but still limited to Shuttle-level reuse. i.e refill the steel SRBs and rebuild the SSMEs). I'm really liking this idea and am seriously wondering if "blocking the pilot's view" killed it , was the Spirit of St. Louis (another famous vehicle that blocked all forward visibility) on display near the capitol (the Smithsonian Air and Space museum didn't open until 6 years after the Shuttle was started. Some of the exhibits were in the Castle, but I was extremely young when I visited then).

I was assuming that the uranium would shield the plasma from the magnets, causing the plasma to escape and destroy the reactor. I'm not sure there is really a difference between the two explanations (there is an academic difference if the uranium atoms don't move, if they do they are the same). My guess is that you would have to make the magnetic generators out of uranium* and actually have them react while conducting all the electricity and generating the necessary fields. Very non-linear design, very difficult, but assuming all the likely showstoppers (starting with getting the uranium to conduct electricity) don't stop the show, it might be something (although there are likely millions of more likely ways to make a fusion reactor. Learn the issues first...) Er, as far as I know, while you can get the temperature and pressure for fusion, the problems with energy production mostly come from getting it to sustain itself (tritium and neutron issues are for later). This is certainly a means of producing said temperatures economically, while getting the pressures is going to be another story (thus all the issues I mentioned about magnetics. I seem to recall my chemistry professor mentioning that heat wasn't a big issue in chemical engineering, but pressure was the huge cost. Now think in terms of pressures higher than any chemical reaction needs...). If you really like this idea (I like it, I just can't see any way to maintain the pressure), find out when it was proposed in the 1940s and 50s (or possibly in the 60s) and all the arguments against it (there really isn't anything new under Kerbol, there is just stuff that there wasn't infrastructure and failed and stuff that there was infrastructure for that worked). Try to figure out how modern technology can get around those arguments in ways that were inconceivable in that era. Then propose it again. * I'm assuming some sort of alloy. Pretty much all U, and expect to need more U235 to replace both the U235 and U238 that the alloy stuff for conduction is replacing. Also conduction goes down with heat, so don't even think this will ever work.

This should be the end of my short restart of 1.0.5. Lessons learned: Forget anything you knew about going into space pre-1.0.x. It isn't hard, but all the problems are encountered coming down. Expect kerbals to die due to this. The kickers may or may not be all that valuable. The 75k cost to upgrade the landing pad isn't bad. The 90 science costs to unlock them is another story (if you can get them as experimental, go and unlock the pad). The ability of a kicker to replace multiple parts (cost to unlock >30 parts: 337k) is invaluable (in funds, you still could begrudge the science costs). I'm curious as what Squad uses for goals of career mode. Since starting with the science unlocks, it seems that they have made it more for experienced KSP hands to have new goals with KSP. Once they added the part limits (and made things like the "open the tech tree in two missions" effectively impossible, it seems like it is more for beginners. Currently, it looks like there are two obvious paths. The first is the beginner's path, which follows the contracts. The second is the NASA path, which follows the abilities of the rockets (the "milestone" bonuses help build this path). My main issue is with the "beginner's path", mainly because it wants to go to Mun first, and also because that it puts an artificial "450k Mun-tax" to block you from a kerballed landing (and soil sample). The "NASA path" [how I ran this game]: [optional] probes to Minmus/Mun (strongly recommend for beginners) [make sure you have thermometers and barometers before going to Duna]. probes to Duna/Eve (barely any more delta-v than Minmus/Mun, but complications and need for external websites and examples make them less than beginner friendly). [Duna unlocked ~500 science, and I botched the landing.] kerballed mission to Minmus [monster/unwieldy kicker plus 2 liquid stages and tons of delta-v gave me 5 different landings on Minmus (not beginner friendly, especially that rocket. Still had pretty wasteful landings) full science dance=>3000 science.] kerballed mission to Mun [quit before this. Basically the tech tree is unlocked enough to no longer be "starting out"] However, the contract system gives us these in roughly the opposite order. To add to the injury, the cost to unlock soil samples is 450k funds, which is quite a lot at that level (but you should cover it after a Duna probe). There isn't much point landing a kerbal on Mun/Minmus without unlocking this level. This might not be much of a bug. You probably need to learn enough about orbital mechanics via "put a satellite in this orbit" missions to go to the Mun by the time you can afford the soil samples. My real objection is putting Mun first, mostly because the lack of flat areas and the high delta-v requirements (landing on Minmus is beginner friendly, not so Mun). Note that NASA fired Mariners1-7 (all to Mars) before launching Apollo-11 (to Moon). The Soviets fired plenty of interplanetary probes in that time as well (but presumably they knew the issues and were willing to do *lots* of hand/slipstick calculating on paper).

I've seen KSP Minmus landers that did this (land on wheels and set the brakes to minimal. Presumably only useful for landing on the Great Flats). Unfortunately when I tried it myself the hanger insisted I wanted VAB symmetry. As far as "outside the box", it looks like a carrier-style landing with a loooong deck (think railroad, not carrier deck). Not manned*, and the tailhook isn't going anywhere (unlike on a carrier), so maybe it might work. For extra bonus kerbality, add magnets and try to generate power from the tailhook and use it for a railgun launcher (no way you can store that power). * Note that considering the huge infrastructure costs, accounting probably wouldn't notice the loss of life. You still don't want to cause the second great space mutiny.

I'm still wondering what assumptions you are making and how you are grading these devices. My understanding is that ISPs tend to be 4000 or less, and there isn't much point in going higher. Also expected burn times should be in months or years (at least one such drive fired for several years in the lab). If the problem is that the mass of the solar panel dominates the mass, you need a smaller solar panel (and a smaller, presumably already designed ion drive) and more xenon (xenon is expensive, so try making the solar panels smaller before using too much xenon. Or use argon (and much get much less Isp). One thing that keeps getting ignored in such calculations is just how are you going through the Van Allen belts. My guess is that the ship will be built in LEO, slowly trudge through the Van Allen belts and not be boarded until ready for Mars intercept (i.e. 3/4 of the burn to Mars). [This gives at least one mission for SLS, or simply use Dragon/Orion/Soyez connected to some booster sent up that doesn't have boiloff issues (possibly by docking/burning fast enough).]

I prefer unmanned for career, but would probably use kerbals exclusively in tutorials. And I would try to encourage tutorial use before career (I think there are issues with career difficulty which might be best fixed by tutorial usage). In practice, the current system appears to work (if you have the skills): Kerballed launch (nowhere) [could be unmanned if you had the tech] Kerballed [Bob or other scientist] launch to space. Do the science dance. Kerballeld launch to orbit [Jeb or Val for SAS, science dance already done] grab all the "EVA over biomes". (optional) unmanned launch to Mun and/or Minmus unmanned launch to Duna and/or Eve (Duna's window pops up first). manned [use Bob or other scientist. SAS can be provided by octo-core] to Minmus. Extreme science dancing. Note that not only the probes can get to Duna/Eve with barely more delta-v than needed for Mun/Minmus, you don't want to send a Kerbal there until you can unlock soil samples (which costs 675,000 kerbucks to unlock).

Did you measure crowd levels of protest, or simply media reports of peep level. NASA could have said "look, shiny!*" and the peeps would have gone for naught. * or more appropriately "look, blood!" (it bleeds it leads).

Two orbits then. Sounds like they weren't leaking LH2 all that badly.

Yeah, that's why I suggested looking long and hard at why you want an OS in your system. Any code *you* haven't debugged isn't debugged for your code. If you can do the job more simply with less code (even if you have to debug a little more of your own code) it should be better. Of course, for the things that want something like Linux, you better hope that you can reboot that computer *anytime* and not rely on it for real-time operation (I'd assume that the payload parts will be the things that need something as complex as Linux and be willing to deal with those issues, while the booster/navigation/landing systems need to be bulletproof).

Have you seen the xkcd "time vs. understanding of orbital mechanics" yet? Most people aren't up to the level of "high school physics" yet (and easily well behind Randal Monroe-types before HS physics at that). Guess who buys Hollywood tickets? Things I didn't understand about orbits before KSP: Escape velocity != infinite distance. Escape velocity gets you <=2AU distance from Earth, maximum (you're orbiting the Sun at 1AU until you spend more delta-v). Even Scott Manley blew this in an early KSP video (of course, I don't think KSP included Kerbol in that one, so technically he was "right"). How to get to Mars (and any other planet). Yes, I *knew* about Keplar's laws, I just didn't *get* that you needed to burn (once) to a new ellipse and map it onto the trajectories of Earth and Mars (then capture). That was pretty obvious, in retrospec. That nearly all (0th order mechanics) could be summed at "burn at perigee: raise apogee". Once you learn that, all else are details.

A lot depends on passenger travel. I suspect the value of high-speed China-US-EU travel to be pretty huge. On the other hand, this is obviously optimized for orbital and beyond (no idea if you could lose less than 88% by doing an escape burn right after leaving the atmosphere but before circularization). You need a huge percentage of the orbital velocity to get a significant suborbital flight (much beyond the Concorde's NYC-Paris range). And people wonder why throwing a rockets makes sense. This has to be the most workable means of getting into orbit I've seen. I wonder how much a 200WM maser really costs, anyway? Too little for NASA, too much for private industry?

Trying to get a non-trivial boiloff for the Earth departure won't be easy. ISS resupply missions tend to take *days* to dock with the ISS (then again, nothing there is boiling off). A low boiloff mission pretty much means launch, circularize, rendezvous, dock, light the engines and go to Mars in as few orbits as possible (preferably one). This just doesn't seem to fit the slow count down and launch that would charecterize such an operation (although I'd assume that the full checkout less fuel would be done prior to fuel launch). I don't think Apollo 11 did more than a single orbit in their "parking orbit" (it was pretty low, they wanted that Obereth effect), so there is presumably some precedence for such a quick check and go (which was boiling off H2 as well, wasn't it). You could presumably do such a "last minute fuel launch", but it would be a white knuckle thing. Steely eyed missile men need only apply. Anybody know what the Chinese think about nuclear power? NASA isn't the only game in town, and I've never heard of congress planning on giving them a budget to Mars, nor a president willing to follow a previous president's space plan (Johnson got a lot of mileage out of following the "martyred" Kennedy in other areas, so presumably was willing to maintain Apollo. Nixon put a halt to things as soon as possible). As far as the hostility to nukes dying down, I can only hope that it has something to do with the fact that nukes replace coal plants and don't contribute (significantly) to global warming. I don't really believe that, but the idea of giving guys from Enron the keys to a nuke plant does not give me the warm fuzzies either.

Good question. I think space-x has mentioned using linux. Note that if you go with rad-hard (which typically involves using saphire and even more exotic compounds) you are probably using a microcontroller from the 1990s that doesn't have room for an OS, even one from that era. You might want to think about what an OS is, and why exactly you want one. For multitasking? Just how much latency do you want on the "real time stuff", anyway? Do you need your memory managed? Do you *really* want the OS to decide which page it is going to swap out? Do you want your peripherals abstracted? If so, why? I'm guessing that some sort of "RT Linux" is used a lot, because the programmers can get right in and rip all the parts they don't want out of the thing. Just remember, throwing hardware at the problem works for a lot of problems, but has trouble with some issues (latency being the one that matters in rocket science, although scaling and other issues probably come up as well). Just remember that every time the OS steps in and offers to do something for you, that's a lot of code to check *exactly* what it is doing for you (and how long it will take). Insert "real programmers" story here, and how NASA employs "real programmers".

Luckily for us, Claw was just hired as an official developer. Hopefully that means that bugfixes like this *will* show up in the next official release.

You have to remember that adding something like antenna range means you not only have to debug antenna range, you have to debug it with everything else. Adding even a little bit breaks things in other places. My only problem with the antennas is that there are multiple types, with no advantage for all but the earliest one. Are the "stupidity" and "bravery" traits ever going to be used? Or are they just going to be silly shout outs to all the earlier editions? I really can't see any possible way to use them, especially if leveled kerbals have no difference in actual flight (delta-v and such). I think I would miss seeing such choices, especially as long as we can choose which kerbals we are going to make astronauts. It adds a little personality, otherwise all we have are the (mostly random) names.

Because mass in space is cheap, and platinum on Earth is not. Not sure what to do about mass hysteria. Not even sure if there is any way to be sure you could hit something the size of the Australian outback. Maybe try the bits of the Indian Ocean MH370 was lost in (presumably low on ships as well as other populations), or even the Indian Ocean well under the equator (probably too deep to dig the rocks out). I'm assuming the whole point of asteroid mining is to get rare stuff to Earth, which means *something* gets de-orbited, and putting it inside a spacecraft means huge costs in getting the spacecraft up (consider the shuttle...). The second most common would probably just grabbing some mass for shielding, and finally some sort of fuel grab (presumably water for cracking. But methane should be out there). I wonder if you could smelt an asteroid in place (presumably using rotation to separate densities) and then wind up with a perfect sphere? That might be something you could easily calculate de-orbiting landing zones (although not to Luxembourg-level of accuracy). Does platinum crack water as well, or at least help crack methane better? I'm a big basher of "hydrogen economy" ideas, but would have to re-evaluate the idea from start to finish if such an important catalyst as platinum was suddenly cheap.

Any explanation on how they are going to do the mining? My assumption would be that the first "mined asteroids" would be to find an asteroid with a lot of platinum (or something else that would *still* be valuable if you had an asteroid's worth) and drag the thing (warning: Rosetta-Plilae's "grabber" didn't work. It's harder than it looks) back via ion-thrusters. De-orbit the thing with a semi-controlled area on Earth (guessing where an asteroid hits won't be easy, just don't do it anywhere inhabited). Then go collect your platinum. The big problem with this approach is that Luxembourg is one of the last countries in the world to make such a strategy work. Sure, there are the oceans, but all that means is that anyone else who gets to "your" asteroid can claim them under maritime law as salvage. Your best countries to claim an asteroid would be Australia, Canada, Russia with countries along the Sahara also a good bet (assuming you could hit one of the countries you have claims with and that they could keep other claim jumpers from getting to "your" asteroid first). It might make great PR copy, but I don't see any advantage to file a claim with Luxembourg. You need mostly uninhabited spaces and fairly significant law enforcement, these are things that historically don't go well with each other.

There are a bunch of factors to consider: Delta-v for all rockets going there: anything over 70km will cost more. You also get more Obereth effect *leaving* the station for parts beyond LKO from 70km. 70km allows for 4> (50*) time warp. 120km allows for 5> (100*). 240km allows for 6> (1000*) Eccentric orbits allow for easier "brute force" docking because of the low velocity near apogee. I think I'll try this for other cases (Munar docking and what not), but I don't think many players do this for space stations. This even allows tricks like Munar insertion, (wait till the Mun is aligned with where you are going), and deinsertion for the right ejection angles to get your Obereth effect back for going to different planets, but that is a little odd. Generally, a more or less circular 120km looks like your best bet. If you have a contract, check that. Typically you want to fulfill the contract, then move it where you want.

Anybody start with 1.0.5? I'm curious how many brave kerbals died learning the various tricks to get into space. After fussing around with it a bit more, it looks like using two SRBs* (with the second one set to half of maximum thrust) and two decouplers. It takes an *immediate* pitchover (if you wait past ~300m/s, you can't change your attitude). Coming down from a ~45degree angle will save your kerbal (and give you a generous ~10 seconds to hit the space bar and open your parachutes). Hopefully new players can either see the importance of liquid rockets or figure out how to change thrust on SRBs. Hopefully squad is checking things like Steam's "hours played" and not noticing a sudden peak of players who have played for more than 10 minutes but less than an hour or two (of course, that might be common across all Steam games, but I'd be worried about *that*one*mission being such a problem. I'm not sure if my feelings about orbit should be the same. I suppose that my feelings that "space should be easy" come from starting the game before 1.0 and too much space-x propaganda (look at how many X-prize competitors fell by the wayside), but it really feels like getting into orbit is easier than surviving the return from space (largely because coming back from orbit *forces* you into a survivable angle of descent. * PS: The "three hammers" trick didn't seem to work for me. I seemed to be stuck with ~30,000m tops. I was afraid to use less angles, and thus wound up with the two hammers and two stages rocket.