Requia

People keep saying this, but its not true, it CAN'T be true in stock KSP. High TWR rockets are capable of a high enough LKO payload fraction (over 24%) that it would be impossible for a low TWR rocket to make it to orbit even if its fuel tanks and engines had no mass at all (mods with cryo engines might be an exception, as those very much can get to orbit with lower fuel ratio). The cost thing is more complicated and not subject to simple disproof, but that people keep repeating it alongside the mass thing suggests that whoever originated the idea didn't know what they were talking about.

Is there anything to suggest that it was ever part of the plan to make the service module or heat shield re-usable?

It is reusable. Which suggests that the other stuff may have been added back as well.

I do wish he had pissed his way into obit but I guess you can't put chemistry in a Hollywood movie.

It blocks radiation but so do things like an atmosphere (even a wimpy mars one) or thousands of kilometers of rock which tends to reduce the radiation by very close to 50%.

A) They flew 2 of the early model and 13 of the finished model. that doesn't at all support the 'we'll fly it once then cancel it' paranoia. Also 68? The last one flew in 75. the Saturn V was developed on a drastically short timetable, paid for by overengineering everything right down to the screws in order to reduce the amount of time spent testing components. The result is that there was to be no significant price reduction in future Saturn Vs (to get a handle on this, 17 were built and 15 were flown at a inflation adjust cost of 40 billion), they'd have to have essentially started over in the design process to get the price down. SLS doesn't have that problem because its being built on a normal timetable.

As you point out, earth temperatures are very deep on Saturn, if you have a Earthlike temperature inside compared to very cold temps outside you don't need to use inherently lighter gases, because the high temperature gives you lower density at the same pressure. A hot air balloon instead of a blimp. Though I'm not sure why you would. All you're doing is settling down into a gravity well instead of orbiting.

The problem with fated linearity is its trivial to come up with a situation where things HAVE to change. Build a time machine that sends radio signals back in time and set it up to only turn on if it doesn't receive a radio signal. If it doesn't receive a signal, it sends the signal back in time, if it receives the signal from the future, it doesn't send it. Run the experiment a million times, is some fantastic coincidence going to break it for unrelated reasons every time?

Our history suggests military minds aren't usually great when faced with new technology, there are some very brilliant exceptions, but a lot of WWI generals were stumbling around in the dark with how to attack a position defended by barbed wire.

The 21st century designs (not actually flown) are water based systems. Debris is only a concern if you plan to stay in LEO.

Logistics. Even if we can't make anything that aliens can't make, you (normally) have to bring everything with you in space. We could essentially be a ready made supply point for whatever it is their ships need (food, fuel etc), even things we can't currently make but could soon with assistance.

There are no real political barriers, except to the extent that politicians screw with NASA in general, Prometheus (a full project to create a 200kWe nuclear spacecraft) was killed in order to fund other NASA projects, not because people objected to the reactor. It's quite a bit safer than RTGs, so anybody who tried to object would look like a fool once its pointed out that if the reactor crashes into the ocean, exactly nothing would happen if it hasn't been turned on yet.

AM 241 is *really* radioactive relative to its heat output, radiation shield mass is a concern even for unmanned spacecraft. If you need the heavy shield and 'do not let this reenter under any circumstances' protocol you may as well use a proper reactor on a manned vessel (for unmanned there's a problem with needing to refuel, though Prometheus was targeting a 20 year mission so its still possible). Doubt you can beat solar in LEO though. - - - Updated - - - That optonuclear thing is pretty neat looking, the decay chain of strontium 90 is almost entirely beta radiation, the gamma is pretty much insignificant. Solves the shielding problem nicely since the whole goal is to capture the energy of the beta radiation anyway.

The RS-25 has an overdrive, not the 109% operation, that's just normal operation at this point, but it CAN hit 111% in an emergency, its just not considered reliable at that level.

Concerning relative velocity: relative velocities like that don't exist in the same orbital plane, unless you add that much v. (exception for suborbitals on the same plane, since you do that by not adding v). If you want to get huge relative velocities, you either need to add the speed, or be starting from a way different orbit. A satellite with a BB gun can't do anything to something entering its orbit, but it might be able to waste a polar spy satellite (low odds of a hit, but if you have a thousand aimed shots...)

Then why exactly did they go through all the trouble to test sabatier reactor on the ISS? That sounds like a pretty serious ISRU push, given the minimal benefit over CO2 scrubbing+electrolysis this close to Earth.

I heard 29t, if its 40t that's a hell of a lot better, we can use that. Well, its mostly a paperweight, but the heat shield is sortof the reason you'd bother to lug it to mars, even if you plan to aerocapture the main SC for reuse its waaaay easier to clear that plan if nobody is going to be inside it.

Except of course that falcon heavy without crossfeed barely even qualifies as a heavy lift vehicle, let alone a superheavy (disclaimer that given SPaceXs history I expect them to get around to it). As for that document, it assumes a 30 billion development cost... which is either completely made up or mistoook a budget proposal that includes dozens of launches for development only.

We deal with the same thing with terrestrial battles, WWI claimed its (hopefully) last victim in 1998.

Nah, those are possible, to an extent, sandwhiching plasma between two magnetic fields has a similar effect. Beyond current state of the art to actually hold it, but there's already an anti explosive prototype that works by detecting the explosion before the shockwave hits then pulsing a wave of plasma (also a good option). Ships won't explode with antimatter either, antimatter doesnt explode. It makes a ton of gamma radiation, that penetrates pretty much anything, so the vast majority of the energy will pass through the ship. It'll kill crew and fry electronics in the process though,

Oh, I just realized the problem is with the launch system, not the orbital end. Start with a mammoth and 2 or 3 14400s, then add liquid fuelled boosters in asparagus configuration.

Do you need the fuel tank to be full when you get there, or will you be hauling some ore up? a Kerbodyne 7200 drained of all oxidizer + 4 LVNs will get you an extra ~95 tons of payload to play with, launching 115t stock isn't too hard iirc.

A) SpaceX is charging ~125 million on average per ISS delivery, and that's not even the full payload for at least some of those. I really really doubt given that number the Falcon Heavy is only 100 million a launch. Probably that figure is the estimate assuming successful recovery. Those Falcon 9 1.2 upgrades are probably a long way off. Certainly not this spring. C) Densified propellants? Kerosene is Kerosene.

Why? We've got a more realistic possibility of doing both a manned mars mission and much more in depth outer system robotic missions on the path we're on now, we just don't get to have them for a couple decades. More importantly we'll maintain that capability. No more 3 billion dollar rockets that never fly again after the race is over.

I would in all honesty consider the Ares V to have been a resurrected Saturn V with boosters strapped on. Not that we went that route, but it would have had the same basic structure, modernized variants of the same engines, etc. So I don't know that its impossible (I don't know enough about the Russian industry to be sure it's possible either). But on the other hand why would you seriously want to do that? the cost didn't work out, and with the ISS we don't need regular manned flights anyway, we can do months worth of work on a single flight. If you just want the cargo configuration... well that's basically SLS. I mean its the same thing, they just had the foresight to realize their shuttle tech could be reconfigured to a superheavy launcher, instead of waiting for the whole thing to shut down to try it.