wumpus

There's only so many ways to say "the laws of physics say so". Admittedly, while the theory behind "speed of causality" largely depends on veneration of Maxwell's Equations*, experimental results keep pounding away that it really works that way. * this made all kinds of sense when Special Relativity was published, but hasn't really been the supreme work of physics for quite some time. Nevertheless, its complete indifference to frame of reference has been shown to be true even while quantum level electrodynamics had to be rewritten a number of times.

Actually the "eternal September" started in September 1993 (mostly a coincidence, the name comes from the similarity to the wave of freshman discovering the internet each September), while "All Good Things" (last TNG episodes) aired May 1994. Altavista would start the year after. So the public was already discovering this "internet" thing, although plenty may have thought it part of AOL.

They [the dynamite] aren't required. Engineering installs them (and cuts out the seat belts) to keep line officers from requiring too much abuse of the ship. Either the Line officers haven't realized it, or they simply can't stop the continual insertion of dynamite included parts in the ship. By TNG times, the tradition is so ingrained it might as well be required. I'm pretty sure TNG was over before google existed (although maybe alta-vista popped it up and they stopped).

I'd assume docking. Whenever docking, I'm always wondering why I'm not using a controller. I'd assume that a joystick would work best for normal flight. If so, that was odd timing. Consoles still had a bit of an advantage thanks to RISC architecture and directx overhead (and general microsoft kludgyness in directx). But I guess there isn't much point in "console shaming" now that it generally takes a fps/detail hit to play on console.

Oh, I'm sure somebody got their pork every time. There seems to be a myth that the Apollo program was pitched as anything but "we will show that the USA is better than the Ruskis". But if you listen to Kennedy's speech, that was precisely why we should "choose to go to the Moon". Before that, the original 7 simply flew on rockets based on ICBMs (Redstone and Atlas were both ICBMs, the switch to solids happened after that). Since then, getting Congress to budget for "human exploration" has been difficult. - Note: I've only heard the clips from Bob Fitch's excellent KSP recreation of Apollo 11, and not the whole 17 minute speech. https://www.youtube.com/watch?v=_4GG_ZyXvJw But it is pretty clear that the "political stunt" is the real goal/reason for funding.

I'd be surprised if this were really true. I'd expect "lost" feathers to be part of the "dead code" of DNA, and thus make "neofeathers" based off of mutations of the old feather code to be wildly more likely than entirely new feathers. There are likely a lot of ways to not express a gene, completely removing all traces of the DNA seems an unlikely one. That said, it hardly means that such evolution will actually happen regardless of the need for feathers and the existence of "feather DNA" in the genes. As far as I know, a whale fetus has gills (as do other mammals), but such are lost by the time they are calves. No evolution of whales have allowed them to retain gills.

It comes down to two reasons. First F=dp/dt which traditionally looks like ma, but thanks to the Lorentz transformation goes asymptotically to the speed of light. No known means of accelerating mass will reach the speed of light. The second is that much of Einstein's reasoning behind the "absolute speed limit" involves casuality (effects only happening after the cause). While the "twins paradox" may *appear* to be a paradox, "shooting your father before you were born" would be a real paradox. Assuming that Einstein is correct and that a photon effectively travels over zero time, exceeding the speed of a photon would change the "past". All attempts to get quantum effects to transmit information faster than light have failed (something to point out when people claim to always look to quantum mechanics when it disagrees with general relativity), making this appear to be true. I don't think Star Trek intentionally included "traveling in time and changing the past" because it would be possible in a universe that allows warp drive, but it does balance that bit out (although in reality they would be causing "grasshopper wing" effects *all* the time).

Downsides include needing radiators for both producing and consuming electricity. For sufficiently small values of RTG and ion drives, such is already feasible (and might even be done for a "Voyager III" probe that needs a bit of help for the grand tour), but only if you really need "burns" beyond Mars (otherwise you would simply bounce around the inner planets while gaining delta-v from solar panels). From the sound of it, VASIMIR might be able to consume more power than an RTG can supply. But the real problem is that unlike nuclear plants, you don't have a river or ocean nearby. You have to provide both cooling to the reactor and a "cold side" to your heat engine in vacuum. This is how you get radiators the size of aircraft carriers...

I'm pretty sure you would get some measurable delta-v by strapping a nuke to an asteroid and setting it off. Hopefully within time that such would be enough to miss the Earth (the key is always early detection). I doubt that chemical rockets could provide as much delta-v, although in the end time frames would be pretty similar (you would need months if not years in advance to nudge the orbit enough). I love pushing ion engines, but while they might manage more delta-v, expect it to take years to apply such (it takes years to apply those massive delta-vs to tiny probes, tiny delta-vs to massive asteroids could even take longer).

Bipropellant: pumps are almost certainly right out unless you have a massive budget. It would almost have to be pressurized (pretty sure that peroxide needs similar). I noted in the "amature orbital" thread that propane and nitrous oxide are not only readily available (probably about the *most* available fuels you can find), they are hypergolic (don't expect much sea level Isp, but it is higher than peroxide). link: https://tfaws.nasa.gov/TFAWS06/Proceedings/Aerothermal-Propulsion/Papers/TFAWS06-1026_Paper_Herdy.pdf 600m/s? NASA has a competition to hit 500m/s (after gravity and aero losses): the only serious attempt to show up on this forum quoted a budget of $60,000 (don't forget that 500m/s was specifically chosen to avoid regulations: 600m/s (after losses) might involve paperwork NASA isn't interested in for multiple sub$100k projects). Are you building a liquid engine or a rocket? If you are building a liquid engine, I'd not care about mass and such (much of the reason that the mention budget gets so high) and simply build for a test jig. Building a rocket seems to be putting the cart before the horse, and seems to be so many steps ahead that you can assume the final engine looks nothing like you are expecting now.

The level of acceleration is going to be tiny (although far more than slows down the ISS), so it isn't likely to be an issue at all for mylar mirrors. Presumably you will need similar (possibly dyed black) mylar radiators facing away from the sun as radiators. No idea how well they conduct heat (is mylar used as ESD packaging material? That would put it as "low, but not quite an insulator"). Don't underestimate just how little mass you can get away with for a space-assembled structure. Stretching out the acceleration is always an option (Dawn used micro-gees of acceleration). - Note: if this is too slow for you, you can always use the solar sails to deliver chemical fuel/oxidizer. Use micro-g acceleration for cargo and high power for humans.

How small is the sub-scale New Glenn? I've been surprised at the sudden switch to massive rockets, but for all I know they could be starting with a scale edition.

The whole concept of a monopropellant is incredibly dangerous. The stuff simply *must* be able to break down more or less by itself and recombine energetically. While H2O2 presumably needs a catalyst (and hopefully limit exploding on its own), it is hardly safe. Mixing fuel and oxidizer might be wildly more complicated, but it is used for a good reason.

Eh? Most things I've grumped about pretty much comes down to moving mods into stock. It hardly requires a full redesign. I'd like the level 1 VAB to be a barn (I didn't play back when it was, I just love the image). As noted in the current (as of 10/4/2017) thread, Bill and Bob's names should be reversed (I didn't notice until the thread pointed it out).

Hydrolox is great stuff, but I don't think you can realistically split hydrogen faster than boiloff, so some form of zero-boiloff will be needed. I'd also expect you to purify/store the water, then only split it when a rocket is coming for refueling (no realistic way of avoiding leakage). I'd expect lunar Al/O combinations to happen first (unless we find an available comet or similar). As far as "pinch fission" the problems include "building a 2km superconducting ring" and "expensive fuel isotopes". I'm really wondering how this could be an advantage over a classical Orion (especially one based on H-bombs).

Long term it might have a chance, but how do you manufacture the "uranium" such that it isn't easily set off by other means. While I wouldn't expect weapons grade, having a meltdown thanks to a crash (and resulting high acceleration and compression of uranium) wouldn't be great. "Uranium" in quotes as I doubt that your typical fuel rod compresses well under magnetic pinching. No idea how it works.

Presumably any civilization without [instant] teleportation or similar tech (like the inside of the TARDIS) would have some sort of real estate scarcity (while the American Indians might not have accepted land "ownership", I suspect there were limits to sharing tribal hunting/fishing areas). Not all areas will have equal value, and the time needed to travel will have value. That said, it is scary how much of the global economy (and moreso the US) relies on the artificial scarcity of IP laws. Very few products can't be counterfeited at equal quality at a fraction of the cost (and how many services rely on using such goods?).

And this is for [scribbles using equations unused for decades] 500m/s delta-v? There's a reason that Copenhagen Suborbitals hasn't put anything into orbit (even though they are working with turbopumps). Are you making a big deal about guidance systems (plenty here assume it is critical)? * For 45,000 feet, I'd rather use a weather balloon. If there was ever a reason for balloon-launch, this is it. I suspect that launching at 30,000 and trying to get 75,000 feet would be easier. Or possibly 73,000 feet thanks to Edward's elevation (since the rules state two liquid fuels).

I don't think they let just anyone blow things up at Aberdeen proving grounds. I'd also be rather careful in asking questions about doing anything like that. My guess is that your biggest concerns are having enough measurements so you can be far away for the duration of the burn, making sure that there is no way for the test to ignite a wildfire (not nearly the concern in Maryland as the West), and far enough away from anyone to avoid making noise (that freaks out neighbors).

The difference between building stations and interplanetary vehicles is mostly engines (especially around the Moon where you need the same shielding as an interplanetary vessel).

"Beating a NASA launch from Earth to Mars" isn't hard (for equal launch windows) but requires an extreme amount of energy&reaction mass to do so. As far as solar thermal, any word on [real] transparent aluminum, or other transparent materials with high melting points? I'm assuming things like quartz and flint crystal would make a good combustion chamber (unlike NTR, you can heat the reaction mass higher than the melting point of the combustion chamber). Don't expect to go much further than the asteroid belt, but the belt is probably the only place in space with a positive return on financial investment. And once again I should point out that you can transport chemical fuels via high-Isp and gravity "cheats" as efficiently as you need, and then let humans get where they need to go in a hurry (ideally re-fueling after each burn or escape/capture pair). Getting fuel from LEO to beyond the Van Allen belts is an issue, which is why you don't hear it suggested in going to Mars, but if you had some easier space access to rocket chemicals it should work well. A "conventional Orion" is likely to only make sense as an air-breather to orbit (I might be wrong, but I think the Isp of nitrogen-based oxidation is pretty bad). There has been some work on the idea, but it doesn't seem to go anywhere. In practice, expect something more like a "pulse-jet" engine that detonates instead of combusts. This gives a higher Ve, but it also tends to destroy the engine. It is also one of the loudest noises ever, possibly worse than supersonic propellers.

In that case we want Big Funded Rocket

My googling has been weak, but I understand that EULAs are at least 100 years old. The point was that copyright law wasn't settled and record companies had to license (but not sell) their records to prevent anyone from copying their records (why you couldn't do that with books/sheet music is beyond me, but courts have made stranger decisions). I'm not that certain that EULAs were all that popular in 1986. I don't recall seeing any on any 8-bit machine, and only saw them when I moved on to PCs.

Mass Transit and the United States is pretty complicated. I'm not at all convinced that moving the amount of vehicles needed for proper mass transit is remotely efficient, especially considering how much reserve capacity you need. An unmanned uber/lyft prius/leaf is almost certainly going to be more efficient especially considering inperfections of planning 20 years ahead of time. "The things that make life worth living..." this is a topic for another board and one I could easily fill. Suffice it to say that "imaginary property" [IP] makes up a huge amount of the modern economy and simply breaks all the laws of supply and demand. It isn't an exaggeration to say that IP has shown capitalism to be obsolescent. Edible landscaping is unlikely to go over well in the US. Simply trying to stop areas from using legal pressure to force lawns on homeowners in places completely unsuitable for such things (Southern California and Arizona for a start) would be a good place to start. I'm not sure there really are many restrictions on height (although I will rant about my state [Maryland, which borders Washington DC] requiring about half the land set aside for homes built on one acre [4000 sq. meters] of land. This is effectively a massive mansion subsidy). There is a hard limit in Washington DC, but considering I've stood at the top of the Sears tower [no idea the current name] and looked *way* down on what was a massive steeple in Victorian times, I don't expect anyone to allow the same to be done to Federal buildings. Those who need fancy buildings near DC can [and do] build in Arlington, Bethesda, and Silver Spring. Invest big money in sustainable materials. While I'm sure some of this money will create some tech that will escape out of the lab, I like to claim that there is no greater R&D project for sustainable energy than the billions [trillions?] being spent on mobile phones and other tech. Build a better battery and Apple, Samsung, and Google will be at your door bearing gifts.

SLS isn't flying now, but that hasn't stopped this thread. I'm reasonably sure that an unmanned SLS will fly at least once, but I wouldn't be at all surprised if funding continued for 20 more years whether or not they launch a second rocket. I wouldn't be at all surprised if one of the reasons Blue Origin built a facility out at Marshal Flight Center (Alabama) was to try to scoop up some SLS funding. If you can convince the Senate that SLS needs to go to Mars to keep the pork going, then SLS will be funded for Mars. Since the thing is simply overpowered for almost any other use (it looks like what happens when a KSP player simply designs for delta-v without looking at any mission requirements), this might just work (or it might kill SLS. You never know how things work out in Congress).