wumpus

Personally, I suspect that if an alien world wanted to conquer the Earth, the first we would notice it would be during the terraforming phase. Possibly simply a probe injecting new life forms to adjust the atmosphere as necessary and prevent any lifeforms from interfering with said change. Aliens capable of crossing interstellar distances would be as interested in "conquering" us as we are interested in "conquering" ants. One possible example would be to add humans to a planet with carbon-based energy sources near the surface. - this wouldn't be true, especially seeing that an ice age would be a good time to "adjust" humans.

There should probably be some sort of computer science law that states that the code is always more speghettified than you think, especially if the code is written in a language that allows object orientation.

I'd assume that any such separation has to be done outside the atmosphere. Whether this means using air breathing engines that need oxidizer added past a certain altitude (SABRE), auxiliary rocket engines (traditional KSP spaceplanes), or use the second stage to drag them both out of the atmosphere (requires far too large a vacuum engine, and almost certainly asparagus plumbing). None of these are very good, and the choice between these and atmospheric separation help keep spaceplane designs on paper. I also have to question the very concept of using an aerospike as a second stage engine. A classic de Naval nozzle will be more efficient in vacuum, and almost certainly more efficient in such low atmospheric pressures such as a spaceplane's ceiling (an ideal "vacuum de Naval" nozzle requires an infinitely long nozzle, so any real nozzle will be designed for at least some atmospheric pressure). The X-33 only made sense as a first stage, and would require considerable rework as a second stage.

The Sun basically emits light two ways, first by direct fusion which pretty much goes however it will. Second through blackbody radiation of its 15million degree Celsius heat. Convince a plasma to somehow "turn black/white" in opposite direction and the sun will have significant thrust (while the fusion energy will certainly far exceed the blackbody radiation, the blackbody radiation should be more than enough to get it moving fast). While this only uses a small fraction of the Sun's energy, it at least is an idea of how to harness such power.

That's somewhat similar to the argument of bringing a lot of platinum. You might crash the market, but you'll likely drive up the demand for semi-cheap platinum (for catalysts and whatever else they want it for) and you'd have a (short term) near-monopoly on the stuff. I doubt diamonds would find such a use.

If you have anything like the output power of the Sun, you should be thinking interstellar flight and not the wimpy little delta-vs needed for orbital velocity and hohmann transfers. Change the albedo of the Sun (or ideally some other expendable star) and you might get it to move in a specific direction. Wait long enough and it should achieve relativistic velocities (hopefully your albedo changing doping didn't cause the fusion process to change too drastically) under somewhat iffy control. What you have is a single-use death star, only one that likely gives away its approach long before it crashes into your sun/planet/whatever. PS: you want to give the bright/exhaust side a "dark albedo" and the other side a "white albedo". Why? Because black bodies in black body radiation radiate the most energy. Colors absorb and transmit light at similar rates.

Platinum is sufficiently useful (for things like catalysts) and gold's inability to oxidize would probably be wildly more useful at a lower price (not to mention conductivity, and use for connectors). But any "space mining for Earth" would almost certainly have to come from the asteroid belt: the vast costs of dragging something out of even the Moon's gravity well would cost more than any Earth extraction. I think the cannonical example was that even if the surface of Mars was covered with gem-grade diamonds it wouldn't justify the costs to pick them up and bring home (and I'm fairly sure those prices are true after taking into account just how much mass Falcon Heavy can "cheaply" throw to Mars intercept).

How do you get down at 30,000ft?

Considering that a cruise missile's mission is primarily flying low across a long range of terrain and has a single use engine, it takes some pretty exotic fuel to nudge the price of the project at all, no matter how many you make. U-235? Since such a thing would presumably be carrying nuclear weapons anyway, I'd assume that putting fairly refined uranium into a device that occasionally gets shot down isn't *that* stupid, but sooner or later some joker of a president will want to use one for a conventional payload in a place where Iran (or similar nation with nuclear ambitions) might get one. I thought the "uranium bomber" was supposed to be manned. And polluting the country it flew over was assumed a plus, at least until somebody asked how you would train the flight crew (it may have originally been conceived as a cruise missile, but before the guidance systems needed for such things were developed).

Designing an F-1 before Apollo would have similar criticisms to SLS today: it was an engine to nowhere. Obviously R&D groups have a place for such things, but there would never be the funding to fix its combustion instability (perhaps using the Soviet solution of more combustion chambers). Perhaps a better example would be the Saturn 1 (aka "clusters last stand"). The thing had a first stage of 8 H-1 engines (apparently an on going design like the F-1) and fuel tanks from Redstone and Juno missiles. The upper stage was another cluster of 6 RL-10s (replaced by a single J-2 in the Saturn IB). All of these were clearly cobbled together from projects before the Kennedy speech, but the Saturn IB was still the primary means for putting men in orbit (when you don't need a heavy lift) until the Shuttle (used for Skylab and Apollo-Soyuz). Still, the project employed something like 50,000 people over 10 years (I assume there was a ramp-up and ramp-down on the total), even a combination of trying to play "KSP with real parts*" and developing those parts into exactly what they needed took mind boggling amounts of labor. One thing the Smithsonian emphasises at the Enola Gay exhibit was that designing/building the B-29 that dropped the bomb (and had already flattened much of Japan) was a *bigger* project than the Manhattan Project itself. I can only imagine what it took to build the B-52 (and civilian jets as well). As an engineer, I'm fairly surprised that Elon Musk could try to use Silicon Valley style engineering and management for aerospace and auto development, but it appears to work. I suspect that Paypal had to be significantly more secure than your typical web page or windows app, and he insists on a stronger engineering foundation than typical in San Jose. In any event, it certainly understands "rapid development and deployment" in a way that aerospace (and particularly the military-industrial side of things that typically runs space projects in the USA) has largely forgotten. * "KSP with real parts" appears to be Orbital/Northrup's main line of work. Just look at how they've made rockets since Pegasus.

What you got was the X-43 project (I've posted quite a bit on that, but I doubt this forum has a good way to search for them). It did show that sustained flight at mach 6.8 was a real possibility. I forgot the whole range of flight, but this one proved somewhat realistic (assuming a "payload" containing just enough hydrogen to produce the required acceleration is enough). It also showed that mach 9.6 was a real possibility, although to get there it had to be boosted to mach 9.6 and have the center of the error bars of the acceleration *just* on the positive side of zero. Don't expect to actually hit mach 9.6 from barely supersonic speed without a ton of R&D. This project begat the X-51 project, which appears (as an Air Force project expect most of it to be classified) to get to mach ~6 on "jet fuel". Unfortunately this jet fuel is JP-7, the cost is best described as "similar to a good scotch". I don't know if that is the scotch the technicians drink, or the scotch the Air Force generals drink when being liquored up by beltway bandits. Either way, it is far, far, more expensive than hydrogen (although it might even fit in a reasonable fuel tank).

True, but a month or two ago I would have thought SpaceX certainly had the lead in man rating. I suspect ULA holds the lead for American human [orbital] ratings right now.

If you can predict when a radioactive nucleus will decay by some means superior to taking its half-life and plugging it into a Poisson distribution, there's a Nobel Prize in it for you*. There are even devices that generate random numbers this way for cryptography. Here's a link to an example of the difference between classical and quantum computing: https://en.wikipedia.org/wiki/Shor's_algorithm Note there is another class of "quantum computers" out there made by D-Wave. I have no idea if they have solved a problem faster than traditional machines, but it looks likely. You might want to change the name of the thread if you want to discuss optical and/or analog computing. * I'm aware that Einstein went to his grave convinced that quantum physics (at least without a hidden variable) was simply wrong. But even he couldn't find a way to explain the universe any better than quantum mechanics. Then quantum electrodynamics improved on that, and more quantum theory beyond that. And assuming that IBM managed to do exactly what they said they did in 2001 (by factoring 15 into 5 and 3) quantum physics appears to operate close enough to what quantum computer designers expect it to do (i.e. probablistically and not deterministicly).

Why do I get the feeling that "partnering" means "spreading around the pork"?

Reminds me of the quote "I never, never want to be a pioneer" by none other than Seymour Cray (a man responsible for the fastest computers in the world from 1960s-1980s, often holding the title until his next computer eclipsed the old one). Still, Apollo simply had to push a lot of tech in a lot of directions. And developing things like the F-1 engine (which was far beyond a simple scale up of the old systems) might as well been a research project on its own (they blew up an amazing number of combustion chambers trying to find a means of combustion stability). To be honest, I think the idea of massive monolithic SRBs died when Apollo decided they didn't need them. Certainly there are some hefty boosters left with 1 minute burns, but nothing quite like the Aerojet260s. One potential fit might be using something like the SR118 (Peacekeeper first stage) for a large rocket's auxiliary boosters (they burn for 56.6s). Orbital/Northrop has considerable experience using them for the Minotaur rockets, so could potentially try something like that (I doubt that anyone else would be interested).

I'd have to wonder just how large the device to induce and measure the spin of individual electrons would be. Hard drives gradually shrunk in size from dishwasher sized (when initially developed, storing I believe 30MB on a *lot* of platters) to the 5.25" drive of the 1980s and 3.5" drive from the 90s- (in desktops and now typically servers) and the 2.5" (slightly later, but only in mobile). There was an attempt by IBM to make a hard drive roughly the size of a [US] quarter, it may have shipped in some Ipods but was quickly outpaced by flash. Optical media has stayed constant since reducing in size from laser disc [analog video] to CD. Flash storage doesn't appear to have size limitations. As far as I know, even microSDXC has extra size for humans to have something to hold and manually insert. I wouldn't be surprised if electron spin based storage has hard limitations in size, but might be directly done by a chip (and who knows, possibly a "nanomachine" rotating plate). Also the "memory"/"storage" dichotomy can get a little rough at the edges: memory needs to be accessed in groups of 512 bits (one 64-byte cacheline) while storage needs to be accessed in 32kbit groups (one 4k page). Latency also makes a big difference between the two, and I'd expect that dealing with individual electron spins would be so noisy as to require something more like what modern systems use with the 32kbit arrays: LDPC or similar iterated error correction schemes that require at least considerable nanoseconds of extra delay. For a real world example, Intel is trying to sandwich their (well theirs and Micron's) new 3dXP memory as being able to be used for either (and selling the "512bit DDR-like interface" this year).

True, but many of those problem could be reduced by using 4 smaller SRBs (perhaps Aerojet200s?, where 200~=260*sin(pi/4)). I'd expect that this was a valid course of action, and if the lunar rendezvous wasn't the plan they would probably have used something descended from the Aerojet260. As long as the F-1 could get there (and I don't see a single Aerojet260 replacing it, although that might be a good plan for smaller cargo craft) and you needed the F-1, there was no reason to develop some other means of blowing up your rocket. - Edit: Anybody know how they determined the size of the Aerojet260? Did they want two boosters so they only had to worry about a single dimension for their gimbals? I'd assume that four boosters would average out the errors more (and that X-rays could get a good idea of how much thrust each booster would produce. You can X-ray them without ignition, right?). "They would have required an expensive and extensive R&D program to a TRL where they could be considered ready for flight": pretty much the description of the entire Apollo program (although some of it was proven in Gemini, but the whole point of Gemini was to prove things for Apollo).

In Texas? Maybe Californian instincts die hard.

Actually computers had more or less hit the physical limits by then and were only saved by photolithography (the means to make a chip). The issue was soldering just so many transistors to a board with zero failure. This was called the "tyranny of the numbers" and it looked like the CDC7600 was simply the most power computer you could reasonably build (although I think the Cray 1 may have required primitive chips). Photolithography meant you could have thousands (70s), millions (80s,90s), or billions (21st century) of active parts with zero failures* (of course chip size was limited. There are bad chips, and the bigger the chip the more likely to include a fabrication error. But if you have enough duplicate parts (say a memory, or a modern GPU) you can often only disable the tiny portion around the error and keep going. This was difficult in the days of discrete transistors. I think the "tyranny of the numbers" was more an IBM thing (they wanted to mass produce the things after all, and couldn't afford the techs needed to make zero defects possible), but it was definitely a thing until the chip showed up and saved the progress of computers. Had the technologists been watching, they might have also noticed just how hard a fast moving industry can ram into a hard limit. * The chip also has a curious property that makes all Denning principles useless because there is no way to tell a good chip from a bad chip until you finish the job and test it. Oddly enough, the only place I learned about the tyranny of the numbers wasted far too many chapters on Denning principles (which were entirely orthogonal, but presumably the author didn't find out until writing all those chapters). I can assure you that if you put thousands of transistors on boards to build a computer 1960s style the MTBF (mean time between failure) will quickly plunge to zero (worse if you use tubes).

Except that the first chips were developed for ICBMs. While you get to space on limited computers, it always helped to make what little you needed lighter and lighter. The other point was just how accurate Moore's law has been, and that it dates from 1965. Anything that assumes Congress will keep increasing NASA's budget while the Viet Nam war continued, not to mention new Great Society costs as well as the up and coming stagflation was simply absurd. But SST didn't appear to depend so much on NASA's budget (although I'm sure some money seeped through). A better way would be to spec a supersonic bomber that could also be reworked into a bomber and see that Boeing got the contract. In the end, Boeing picked plan B: the 747 and laughed all the way to the bank.

Gordon Moore's eponymous law was 1965. It held strong until the last few years (and you can argue that NAND flash is still obeying it). Hard drive storage might have been growing at an increased exponential rate compared to transistors for most of that period. Other predictions: Anything on air travel that ignores the sound barrier (both increased fuel consumption and sonic booms). Anything that assumes that fuel will get cheaper and cheaper (also auto predictions). Auto predictions: Anything that completely misses that the price of oil could be effectively controlled by Saudi Arabia (and to a lesser extent the rest of OPEC) Anything that ignored Ralph Nader's "Unsafe at any Speed" (reading it you remember that "just because you are crazy, doesn't mean they aren't out to get you". Ralph Nader saw passenger killing conspiracies everywhere, but that didn't mean that the car industry fundamentally didn't want safer cars (not ignoring car buyers not wanting to think about crashing and dying in their new cars). From decades later, it seemed like the only technological expansion in 1960s automobiles was in displacement (probably a non-trivial tech) and sheetmetal. It seemed like nearly all automotive innovation was lead by Japan until the 1990s. Automation predictions: Robots are hard. Robots are even harder if all you have are 1960s computers. Wait around for 20th century GPUs to smooth out the inputs (and do some AI stuff with them) and you might have something. Social predictions: Using a dartboard was likely to have better results. Robert Heinlein might have managed the "death of traditional marriage" prediction, but he seemed to think that the size of a marriage would increase. Instead, it seems limited to two, only with fewer and fewer restrictions on who those two are. Most of what impressed me about RAH's predictions were that most of them were for 2000 (from 1950) and a few were true by 1960. Of the few not true by 1980, one was "proof of life after death" (although at least one researcher has done tremendous work on kids with memories "from reincarnation" that show high accuracy and little tampering) and another one was the fall of communism (which RAH decided to stand with, although there was little hope in 1980). Re: the Saturn V. Looks like you could get two shuttle launches for the price of a Sat V launch. So as long as you had Sat I available for small (just crew?) missions and the Sat V for the big jobs (toss half the ISS up at once) you could probably do better than the shuttle program. Just don't count on getting ~200 launches.

I'd go so far as to claim that Capitalism requires IP law (and local branding monopolies) to maintain scarcity. IP, by definition, has no scarcity. Any physical products might have IP in their designs, and it is often clear that an identical copy can be produced for an order of magnitude less by those unconcerned with IP law. I'd suspect that China or India could manage such a trick by ignoring IP law for quite some time (note that the US rise to power coincided with a period of ignoring UK IP*). The biggest difficulty would be to somehow produce their own IP once they ran out of stuff to help themselves to. Using Socialism would be a start, but I'd guess that the feedback mechanisms of the free market would work much better than some commissar deciding who should work on what IP. How that feedback mechanism would work (raw downloads? Cycle counts of software (by library call)? Likes?) is beyond me. Finally, this isn't quite "zero scarcity". Just "zero artificial scarcity" and wildly higher effective wealth. And there still is the issue about everybody wanting the same bit of land**. * you can similarly trace Western technology all the way back to Egypt and Mesopotamia copying off each other. ** perhaps that IP production is the only way to get the best land?

$20G is one fifth before or after the divorce? I think he's been spending about $1G/year on space, but with a single rocket to show for it. But if Bezos wants to spend his money, I'd expect him to spend it on his own schedule and rockets, not spend most of it on SLS and not to try to meet NASA's crash schedule. And there is no way $20 Billion will cover the Artemis project (as seen on the slide) through the 2024 landing, let alone the rest. NASA expects to pay at least $8.9G on SLS (block 1) through 2021 (assuming they launch on schedule), *then* they have to go through the same procedure for block 1b. This ignores all the other issues building all the spacecraft needed to actually orbit and land on the Moon. It is entirely possible that in the exceedingly unlikely event that Jeff Bezos attempted to fund NASA's vision of Artemis, he would manage to bankrupt himself. Back in the 1980s or so I learned that Congress deals with budgets in billions to one decimal place (i.e. in amounts no less than $100,000,000.00) and as far as I know, that hasn't changed (while costs have changed dramatically). So funding $20G isn't that hard for Congress, it is mostly an issue of explaining to constituents why they are spending such money (and more importantly, making sure "their side" is getting it's share of the pork. A Senate seat costs about a billion dollars (spent by both sides to only elect one), so you need lobbyists to believe that you are a good investment). And the other issue is that NASA's $1.6G/yr budget request is so much obviously a lowball that it makes Congress have to reopen the question every time NASA blows the budget and has to ask for more (if setting aside $20G is hard now, how will it look later. This works well for things like the Shuttle, where the costs explode *after* the thing flies (and also wars, which *always* cost more in lives and money than even the most pessimistic would believe), but not for things where the costs keep creeping before the rocket is even completed. There's always money to throw good money after bad, but there isn't always money to invest in our future. https://oig.nasa.gov/docs/IG-19-001.pdf (source for the $8.9 billion)

In another thread (which is in danger of being locked for political discussions, please don't pollute either thread) I pointed out that the "CLV" (previously called "CaLV" in Constellation, then Ares V as well) needs to be either a Falcon Heavy or a Delta-IV. The Falcon Heavy can deliver twice the mass to GTO (and thus presumably LTI) but I'm fairly sure the Delta-IV has more generous envelope constraints. Starship and New Glen are still paper, so can't meet this crash schedule. Designing and building another rocket in addition to the SLS seems absurd. I guess using a silhouette that resembles my two candidates would look too close to SLS (although both use three identical* boosters at ground level while SLS uses substantially different side and center ones). Expecting an uncrewed flight from SLS in 2020 is a stretch, followed by a crewed flight in 2020 and a block 1B flight in 2024? That's far, far faster development on SLS than we've ever seen from Boeing. SpaceX would presumably have to build a few Falcon Heavy boosters to be ready to launch 18 flights including 4 in one year (I'd expect they'd have to share with Delta-IV anyway). But I can't see ULA+Boeing building 18 Delta (especially Delta-IV Heavy) rockets *while* getting SLS back on schedule. PS: I've always thought this is what NASA should have planned with post-Apollo 11 missions. Use one Saturn V to deliver a much heavier lander to lunar (probably high lunar orbit for easier docking) orbit and use the other to bring the crew back and forth (it can be more spacious for the guy left in space thanks to not bringing along a lander). Of course this means in hindsight that without a lander or means to perform an orbital insertion burn and dock with one, the crew of Apollo 13 would certainly die. * not *quite* identical, but true enough for the purposes of a poster.

Note that while SpaceX might be Musk's vanity project, without it and Telsa he likely wouldn't crack the Forbes 500 richest Americans. Hardly "nothing left to conquer but the sky". Nitpick: the first real operational "computer" was likely the Z3. This computer was built more as an "art project" and had to be kept secret from the [censored German] government, or they'd take all the components as a "misuse of war materials". Shortly later the ABC computer was built, presumably as an academic research project (note, the ABC was neither programmable nor Turing complete). The ABC lead directly to the famous ENIAC (Mauchly had a good look at the ABC computer before building ENIAC). ENIAC (and most computers to follow) was most certainly built for governments (as was Colossus, a British computer built to crack codes a little after the Z3). After Eniac/Univac decided they could sell 3 computer to the government to fill the nations [electronic] computing needs, IBM (and the seven dwarfs) starting building computers for large companies. Eventually one "dwarf", Digital, decided to build computers for smaller companies and launched the minicomputer. One of these (the PDP-9) was so cheap to make Steve Wozniak wonder if he could buy one (could have happened any time between 1965-1975). He was quite disappointed when his father told him it cost as much as his house (Silicon Vally housing prices hadn't taken off yet). Steve wouldn't be able to make computers for people until he saw MOS technologies selling 6502s for $25 a pop (1975?). Finally, as much as SpaceX has managed to drop the price of entry into space (and don't think for a minute NASA has been trying since 1969, although Orbital did make some progress), it is still staggering. And even if you look at only the fuel costs (a tiny portion of the cost to go into space), it is still sky-high. It will be decades before all the low hanging fruit will be plucked before things air-augmented boosters and ramjets will be suggested to lower the cost into space (assuming those who make such decisions still care about such things), and possibly make space available to the general public (assumes that the wealth distribution will maintain constant, any discussion of the probability or desirability of such should be scrubbed). To get back on topic: NASA really doesn't build anything, they give specifications to contractors and let the contractors subcontract things out and provide something to that specification. Thus it has been since at least Apollo and I'm sure NASA/NACA didn't have the massive infrastructure when it was new to build Mercury, so it did the same thing the DoD does: put out a spec and let contractors bid on it. What has changed drastically is that things like "commercial crew" has a spec like "get three astronauts to orbit with a high (specified) margin of safety" instead of their usual "block diagram level + plenty of physical envelope dimensions" that micromanage the contractors. I've mentioned that Falcon Heavy looks ideal for "cargo launch vehicle", Delta-IV heavy also exists, but can get only half the mass to GTO (and thus presumably LTO). Starship and New Glenn are still paper, so can't be considered. No idea if the Falcon Heavy or Delta-IV can deliver Blue Moon to the Moon (Falcon Heavy has nasty envelope issues, Delta-IV has mass issues), but it is almost certainly paper and could presumably be made to fit whichever restriction needed. I'm not sure why, but for Apollo the Command module was the "glory contract" of the Apollo program, although the lander seems the coolest part. I imagine that Bezos would do what it takes to get Blue Moon to the Moon. Atkins Rule of space design: 39. Any exploration program which "just happens" to include a new launch vehicle is, de facto, a launch vehicle program. Artemis is fundamentally a job program for SLS, so it already is a single launch vehicle program, it doesn't need to design another. https://www.youtube.com/watch?v=ouRbkBAOGEw Link goes to JFK's speech at Rice University "we choose to go to the Moon". The money was never there for Apollo for science. The money was always there "to beat the ruskies", it was just that science happened to be a good way to beat them. The US government can hardly be convinced that it needs to go to space for science (how many elected officials will publicly agree that "evolution is an obviously proven scientific fact that the entire field of biology depends on" and then imagine the same crew spending billions "just for science".) Note that corporate support for science hasn't always been negative. Bell Labs was legendary in their scientific output (being a regulated monopoly had a lot to do with that. Do we have any of those anymore?). While Claude Shannon did invent information theory (and everything Bell Labs needed to go digital in 40 years or so, and thanks to their replacement schedule needed that timeframe), plenty of general science was done. With Bill Gates showing himself to be the ultimate philanthropist in terms of lives saved and general well being improved, I have to wonder if the next multi-billionaire might want to try to personally fund science (Warren Buffet's wife pretty much single handedly funds reproductive science R&D). On the other hand, the Tobacco Institute showed corporations just how profitable and effective anti-science could be.