Brotoro

I can't find such a file. Where is it hidden?

Umm. No. Do you mean in real life, or in KSP? Either way, the answer is no. There are no technical reasons we couldn't do interplanetary travel in real life, and it certainly is doable in KSP.

The Apollo Lunar Module's electronics were cooled by evaporating a water-glycol mixture. And, yes, other than that, an active cooling system is going to need a radiator, ultimately (unless we are talking about a heat pump system that's meant to move heat quickly to other parts of he ship...which effectively become the radiators). Agree. The engines are dumping too much heat into the ships.

Regex is correct here.

Well, somebody has been changing some of the numbers already. I appreciate anybody who does that, but if they could please add to the parts description what the 1.0 changes were, it would be clearer what are old numbers and what are new numbers. Thank you!

If you want to consider real fuels that could be used in KSP, I prefer the idea of going with methane/LOX. You can use methane in rocket engines and jet engines, and you can use it in a NERVA with an Isp of 644 seconds. You can make these propellants and find them in space (from water ice, CO2, and methane deposits). Both liquids are moderately cryogenic (compared to LH2), and the overly massive tanks we have in KSP could be because of the insulation and refrigeration systems needed to prevent boil off (engineers say they can make an LH2 tank system for Mars missions that include refrigeration systems that won't have significant boil off). But I don't expect Squad will do this. - - - Updated - - - Lale is correct.

I was looking at some graphs that I had saved as images on my iPad for reference (because the original document is a long PDF that takes a while to download, so it's not handy to quickly look up stuff). The information comes from the NERVA Detail Specification, Performance/Design and Qualification Requirements document. Lots of fiddly bits and requirements. The nice diagrams and graphs are in the last half of the document. Oh...and the engine operating temperatures are specified degrees Rankine (the absolute temperature scale that uses Fahrenheit-sized degrees). Ah, the bad old days. - - - Updated - - - And I apologize for the tangent. But I love KSP because it gives us the opportunity to teach people about rocketry, so I'm sad that Squad is getting this particular aspect of rocketry wrong, and making the nuclear engine have crazy overheating. So I like to take the opportunity to correct people's misconceptions about how a solid-core NTR operates. Maybe Squad will even take notice. So...yes, radiators would be interesting. Temperature control is a very important aspect of spaceflight. But having to add radiator parts to solve a problem that shouldn't exist in the first place annoys me. (And these details about NTRs gets put in just to explain WHY it annoys me, and it's not just because of rage at a change in the program).

Oh, yes. I'm not recommending it be included in stock KSP because it WOULD make the gameplay more difficult, and people wouldn't like it (just like I have trouble with the jet engine spool-down lag when I'm trying to land a ship vertically on jet engines). Besides...if I want to play with a spool-up/spool-down lag, I could edit that into the config file for the NERV and have fun...I don't want to rain on anybody else's parade.

Yes...the propellant used during the shutdown phase gets expended at a lower Isp. So long burns are more efficient for a NERVA.

In real-life, the NERVA could be used for precision burns requiring a certain impulse...you just need to factor in the impulse you get during the shutdown. What we have in KSP is a simplification (just like real chemical engines can't be instantly throttle from 0% to 100% with unlimited restarts). I always thought it would be fun if the nukes in KSP had a spool-up/spool-down lag like the jet engines do. The shutdown phase of a NERVA engine took 45 seconds. This is where most of the tail off thrust occurs. This was followed by the cool down phase (with much lower thrust) that lasts anywhere from 9 seconds (if the main burn was 49 seconds long) to 158 seconds (if the main burn was 1497 seconds long)...or so the table says.

The fuel elements of the NERVA (the parts that get to 3000K when the engine is running) were uranium dioxide embedded in graphite coated with niobium carbide. Later tests were done with zirconium carbide coatings. To shutdown the NERVA, first the fission in the reactor core is stopped by rotating the control drums into position so that the neutron-absorbing sides face the core. Liquid hydrogen continues to run through the core for a while as the reactor core cools down (and the engine produces a decreasing amount of thrust during this phase). When shutdown (after cooldown), the temperature of the core is below 505 Celsius (according to the design documents), and generates less and less heat as the short-half-lived nuclides in the core decay away. All the heat spreads out to the rest of the engine's surface, its temperature will be even lower (not even red hot). During the operation of the engine, the outer parts of the engine will not be very hot because of the regenerative cooling by the liquid hydrogen, just like with a chemical engine (except for the nozzle, which is radiatively cooled).

Nobody said the exhaust of the NERVA is hotter than its core. In fact, I said just the opposite in my last post: "The exhaust is always cooler than the temperature in the combustion chamber for any rocket engine because part of what the nozzle does is speed up the exhaust gasses, and it does this at the expense of heat energy in the exhaust gasses." The walls of the NERVA engine's 'combustion' chamber, just like the walls of the SSME chemical engine's combustion chamber, use regenerative cooling.

I'm often impressed with the strength of the docking port magnets in a new version of KSP...but that's because I'm usually testing them out with a little ship, and not trying to dock a huge ship or payload like I normally do in my game.

No. Look up the numbers. The hottest end of the core of a NERVA is at 3,000 Kelvin. The combustion going on in the SSME gets up to 3588 Kelvin. The exhaust is always cooler than the temperature in the combustion chamber for any rocket engine because part of what the nozzle does is speed up the exhaust gasses, and it does this at the expense of heat energy in the exhaust gasses.

Yes, it's goofy. But you should have seen how goofy it was in 1.0. - - - Updated - - - No, the exhaust of a NERVA engine is COOLER than the exhaust of a chemical engine like the Space Shuttle Main Engines. The core of the NERVA is solid material, which limits how hot you can let it get. The combustion gasses in a chemical engine can be hotter (you just need to keep the walls of the combustion chamber cool enough to not fail).

What's with all you "throttle-half-empty" complainers? Aren't there any "throttle-half-full" guys around here?? Yeah...100% would be best.

Sounds good. Thanks.

How does one do drop tanks under this new system? Say you have a plane with a bunch of tanks all over, but you want to use up the fuel in your wing-mounted drop tanks first (so, like, they can be dropped).

Wow. I never would have guessed that. Are these supposed to represent some real technology?

I'm confused. Are precoolers air intakes? I put mine BEHIND other air intakes. If they aren't air intakes, then why wiuld I care if they have less drag than an intake?

Are they? Can you explain exactly WHY they are good? Are they worth their weight? I'm not disagreeing... My spaceplane worked after I added them. I just want to better understand WHAT they do. - - - Updated - - - Hahahaha! I echoed the Slash man.

I suggest a new strategy: Let the wookie have his way.

Correct. Do you have an example of such a compound that we can find out in space?

I don't think I am missing the point. If you have some LFO to start with, you can use the energy from reacting it in a fuel cell to chemically separate ore into LFO. You should NOT get more LFO than you started with (you should get LESS because no process can be perfect). The reason we can do this with oil is because we are reacting the oil we extract with oxygen in the air. And that oxygen is given to us from hard-working photosynthetic lifeforms that captured the solar energy in the first place. You don't have that free input with the ISRU situation.

Yes. And if you have to chemically separate the ore into fuel and oxidizer, that will require energy. You can get the same amount of energy back when you burn the fuel and oxidizer. But there will always be net losses in the system. Look, I haven't played with the resources system yet, but this sounds seriously goofy.