wumpus

The unbearable awesomeness of Orion was that it was a fusion (or at least nuclear) powered spacecraft that could be built in the 1960s and provide capability straight out of E. E. Doc Smith. What would make your Orion-car similarly awesome would be to build it in the middle ages. Could you see the Connecticut Yankee smashing through knights with such a thing? Or merely going trading between distant places while outrunning bandits? This is most of the issue with any fixation on using pusher-craft much after mid-21st century: they are simply a primitive beast of a device that harnesses the most extreme power source available in a way that doesn't require any understanding or control of the release of such energy. But merely by working at all the provide a massive boost in capability.

Inspired by Red Dwarf, perhaps? Red Dwarf was a British TV sci-fi comedy that starts with the crew entirely dead and the only survivor released from stasis 3 million years later (once the radiation had all decayed). Somehow I think cryogenic freezing is much more likely. From what I understand, it is already standard practice in heart-bypass surgery (granted, that type of thing allows even greater risk than space flight). While doing that, it is impossible to tell if the patient survived the surgery (and cooling) until they warm the patient up and see if they are still alive. Note that I don't think this involves any crystallization, just temperature near or slightly below 0C.

I'm pretty sure there would be no significant differences between a neutron bomb in a vacuum and in an atmosphere. If anything, the bomb would be worse as none of the neutrons would be absorbed by the atmosphere. Such bombs are a bit specialized, damaging life and little else, so you would have to have significant life (like a population) to even notice the damage of the bomb.

As far as I know, for all eras that could possibly confirm life, there are known fossils. So not only must Earth be a good place for life to originate, it has to be great enough to almost immediately generate. Which would *still* make it odd that life didn't happen on Mars (or possibly Venus, but I'd assume that all fossils have long since melted).

You shouldn't need that, I'm fairly sure the ISS has less area of solar panels than radiators. Running thermal lines around starship might not be fun, but probably easier then making a fold-out scheme like that.

My point was that the limits of the 21st century are unlikely to be constraints that are even considered by the 24th. By that point there is no reason to believe we can't efficiently throw enough argon (or whatever atom you want to yeet) at relativistic speeds out the spaceship to reach the desired thrust. With that, you have arbitrarily large Isp and presumably enough thrust to make any passengers have to decide between length of journey and g-forces they have to withstand during said trip (possibly even using torchship means). And yes, there are other ways to make a torchship. I like the idea of a cyclotron flinging particles, largely because it is an extreme example of current systems (ion drives) and clearly shows that the amount of momentum you can impart on any given mass is only limited by your cyclotron.

And here's the issue with the whole thread. 21st (and 20th) century spacecraft design always considers mass first because of the rocket equation and always try to at least minimize delta-v. But 24th century engineers don't care because they have dilithium crystals and other unimaginable tech. We are like 18th century shipcraft enthusiasts sitting around a coffeehouse wondering how much sail a 21st century ship could take and how that would effect cross oceanic travel. Time becomes the limitation, and it looks nothing like anything NASA would ever consider (or even someone who built those little Enterprise NCC-1701 (no bloody A, B, C...) models that always broke). It also shows that mapping out the real requirements doesn't make sense in fiction. The only reason people care about the engines while flying is that propellers are seen as "the cheap stuff", slow, and likely don't have all the other budgets as the big boys. But jets aren't "jet engines" and haven't been for quite some time. They are [high] bypass turbofans. But that doesn't matter at all to the people with the tickets (and unlikely to even the pilots, but they were certainly taught that at some point).

Ok, is the white part supposed to be enough to cool it? Probably a higher ratio than ISS.

Except that there is no way for Starship to power or cool the equipment inside ISS for very long. You'd need the solar array and cooling radiators. Possibly you could dig a "cooling well" (make a lunarthermal heat pump, similar to a consumer geothermal heat pump) if you are on the Moon, but expect to need batteries (or kilopower class nuclear reactors) capable of month long nights instead of ~20 minute nights on ISS. Or you could move to the polar crater (it is a popular choice for base ideas) so you can have 28/365 solar power and protection from solar radiation (especially flares). But it shouldn't be a surprise that ISS has far more capabilities as a habitat than Starship, although eventually they will have to get it to the point where it can sustain people for the months it takes to get to Mars.

Note that "parking orbit" was a phrase used in the Apollo program, although I don't know if it had escaped into the public by 1966 (the show was canceled 1969). Saturn rockets put the Apollo command module in a low (very low) orbit so they could do some quick "go/no go" checks in a single orbit and then use the Oberth effect to go to the Moon. It wouldn't be a useful term when bringing a 24th century starship to a planet you wanted to be "nearby" a landing party. I'd have to assume that the Enterprise could kill all delta-v needed to rendezvous with a planet (trivial next to flying between stars), fly perpendicular to the atmosphere if they pleased at a fairly high mach number (ships built out of unobtanium hold together much better than plastic models of the original ship), and land arbitrarily fast. Or more likely, just have the enterprise use anti-grav tech (or just 1g thrusters) to hold position and have shuttlecraft land on the planet (same way, kill orbital velocity and straight down. No "reentry" needed). Allegedly, models for shuttlecraft were made for the original series, but were never paid for and thus never used. The transporters were quickly "invented" as a much cheaper and quicker means to show crew members on the planets.

Flight speed record. Look up the X-15 for issues there. I think atmospheric friction was still the issue, go much faster (like re-entry) and you get compressive heating. Ground: limit is the tires. I think current record holders use steel wheels with no tires. Also the latest go at the record had to pack up and quit. Sea surface: the key here is to skim the water, preferably generating lift as a hydrofoil. That assumes you aren't "cheating" by using ground effect aerodynamics to simply fly "cheaply" just off the water. Underwater: once you hit cavitation, I'd expect the power needed to scale badly with speed. There's a reason fast boats use hydrofoils to keep as much of the craft out of water as possible. Space: I think Far Horizons has the record here. And not because just Dawn didn't try, but also that Dawn *can't* use her 10k m/s engines for pure speed. Doing that would take her out of the solar system and her solar panels would stop working with most of the delta-v "in the tank". A similar craft with an RTG could pull maximum delta-v.

Time to de-orbit is largely based on the Enterprise's delta-v and the altitude of the orbit. As far as the 21st century is concerned, the Enterprise has infinite delta-v (even with only "impulse engines") and the distance to the surface is presumably in the hundreds of kilometers (trivial for the enterprise). The only question boils down to whether the location the shuttle wants to land is "close" to where the Enterprise is: it can be a 45 minute delay if it is in an "ISS level orbit" to get around. To land (at such a location) any faster, the shuttle would have to massively accelerate, keep the acceleration going to "orbit" around the planet via thrust (far faster than mere gravity would allow), and then decelerate down to the planet's surface. But then, Star Trek (and similar Sci-Fi) assume that each planet has a uniform surface, and landing at any one point gets you to wherever you want to go.

The point of stratolaunch isn't delta-v, but reduced air pressure on the nozzle of the spacecraft. Launching with something optimized 90% or more closer to vacuum than sea level was presumably worth it for Pegasus and Virgin Orbital. They don't care about the delta-v. I'm only aware of 2 teams that managed to operate near mach 7. Hyshot managed 7.6 (the first with net thrust, the second didn't achieve it), but needed to be started at mach 7. X-43 managed 6.8 (starting below mach 3?) and net thrust (barely) at mach 9.6 (starting at mach 9.6). https://en.wikipedia.org/wiki/NASA_X-43 Check the in-flight picture. The shiny metal part is the X-43 "plane", the white part is "booster". Current tech (let alone 1970s tech) is going to require a booster similar to a Saturn V to boost a 747-sized mach 7 carrier (maybe you can buy an SLS or Superheavy). On the other hand, a Falcon 9 booster is perfectly capable of hitting mach 6-7, delivering an upper booster, and returning for re-use. The only realistic advantage for a scramjet is reduced fuel usage (which has to justify the airframe needed to guide enough air in the intakes to achieve the thrust). The cost of launching a Falcon 9 is in the millions and the cost of the fuel is ~$30k. Perhaps with Starship (or possibly a Rocketlabs competitor or even New Armstrong) rocket, the fuel costs will be enough of a significant ratio to add scramjets (or maybe just air augmentation) to Superheavy. For the 2020s anyway, you want to rent Stratolaunch for things like that. Because you aren't getting the delta-v from an airbreather for remotely acceptable cost.

Even if the US public was united in wanting nuclear power (something the anti-nuke lobby essentially made impossible, even while foreign oil dependency was a strategic threat), the sheer cost of building nuclear plants per current designs and regulations would be unfeasible. I strongly suspect that this is due to the fact that while the regulations (and early reactors) where designed and built, electric power was a publicly regulated utility at publicly regulated prices. That is to say, they provided electricity on a "cost plus" basis. And just like with the military industrial complex, the power utilities were more than happy to add any safety features/regulations that would add to costs. Any stockholder lying awake at night worrying about "too cheap to meter" would soon rest easy. While it is quite possible that the fuel providing companies pushed an anti-nuclear agenda, I can't imagine it would be as remotely effective as insiders happily building multiple levels of redundancy to *everything* inside the plants. The way the electricity is produced and sold is no longer quite "cost plus", but the regulations are long since etched in stone. Obviously, once the plants were built, the power companies hardly wanted them vilified and certainly needed them producing for as long as possible. And it certainly turns out that kicking the "decommissioning can" down the road well into the "freeish market" phase of electricity billing is going to bite them hard. With the size, scope, and effectiveness of today's fossil fuel propaganda arm it is easy to assume that it was always such. But as far as I know, it grew out of the old Tobacco Institute and their message "smoking is good for you". I have little reason to believe it was so effective before that.

I have to suspect that renting out Stratolauncher would be a lot cheaper and roughly as effective than any 1970s tech airplane. There isn't that much delta-v to grab (although the first bit matter the most). Obviously too much of a "not invented here" for China, but in general you are reinventing stratolauncher unless you are using ramjets/scramjets/SABRE.

"Today's tech" would probably be pushing it. If you used rocket engines, the mass of the wings would make a huge disadvantage over retro-propulsion landings of a first stage. If you used some sort of air-breathing first stage (or at least included air-breathing engines for the carrier craft), it would certainly be a stretch even if you hired the design team of the X-43. And of course, re-entry of the orbital stage has all kinds of issues.

Quick note: East Berlin, Pennsylvania predates the division (and later unification) of Berlin. I didn't see a "Berlin" nearby that would otherwise justify the name. Tiny place (small enough that an assumed "Berlin" might have disappeared without a trace). Had a job interview there. It didn't go well (suspect I was disqualified for age on sight. Or something. Don't think I had a chance from the start).

Must be pretty common, here's another: http://radiation.umd.edu/reactor/ Wouldn't be too surprised if many/most have been shut down.

Do they have a rocket? I understand that it was originally going to use an Atlas V, but that rocket has since been launched and there are no other Atlas V rockets being made. There's also the soon-to-be-canceled Delta IV rocket and the still-waiting-for-Vulcan-engines Centaur. Sending up your "proof of safety" mission on an entirely new rocket seems like it defeats the purpose, but this appears to be a pork project anyway (that appears to be costing Boeing far more than the pork is worth.

Feeding a nerva water will net a lower Isp than a chemical hydrolox engine (presumably a solar moth could go a little higher, but not much more). You could split the water with a nuclear reactor (or slowly with PV solar), and then feed the oxygen first and then the hydrogen to your NTR (or solar moth). Of course, the real question would be how much water was available: you might not care about the efficiency and simply load up with more water and not have to deal with fuel lines that need to deal with pure hydrogen and/or pure (extremely hot) oxygen.

Bucky's car used rear wheel steering, front wheel drive (with the engine mounted in the rear), the exact opposite of anything since. Doubt it help much with savings, the whole thing was hand crafted by some serious mechanics/craftsmen, but presumably Ford or similar could take most of the design (layout, streamlining) and build an advanced car for a reasonable price. I suspect trying to figure out the steering during a test drive would kill sales if anyone made one now.

There's also the issue that you get much better stability on a 3-wheeled vehicle if you put 2 wheels up front and 1 behind. The Polaris Slingshot comes to mind as an example, as well as Buckminster Fuller's Dymaxion car (I thought Polaris made a much higher "motocyclish" 2-wheels in front trike, but can't find it). You are vastly more likely to be decelerating while turning than accelerating while turning, so you want your wheels ahead and to the sides.

So in addition to super strength (and super sweat), he can also magically increase the rigidity of whatever he is standing on so that (size 20? US) feet aren't piledriven into the ground while throwing a 65 ton main battle tank... [snip] There's a reason these movies (and source material) aren't worth putting on the "science fiction hall of shame" thread.

Oddly enough, there exists a space game which closely models both newtonian physics is reasonably close to current (and near future) tech. I'm sure there is a link to it on this site.

I've heard it claimed that the Japanese did the math and determined that bombing capital ships was so incredibly dangerous that they would lose less pilots/planes per ship sunk/seriously damaged than using conventional tactics. Of course, the Japanese military was even more rigidly bureaucratic than most militaries, so that once such a decision was made it was etched in stone and attacking capital ships would be done kamikaze style. The US lost 35 torpedo bombers alone at Midway (although shooting them all down meant that the sky was clear for the dive bombers). The kamikaze program might have been tragic, but it wasn't "Charge of the Light Brigade" crazy.