AntaresMC

UN is made with UF4 and NH3. U233 has to be cheated or bought fromthe VAB

The umbrella rad can not be deployed outside the VAB, its like multiple configurations. Idk if bug or feature tho. Im curious if this is intended, do you know @FreeThinker?

About your first overheating issue, you need more mass flow, so more intakes and precoolers. A radiator or two to tank the first seconds with barely any intake air helps. Then, fusion reactors need power to self sustain, and MJ can be turned to electricity, so it might be a mix of those. About the thermal generator, its efficiency is maxEff×(1-coreTemp/radTemp), you have very little rads, so efficiency is gonna be low even at low power usage, and nuke reactors cant throttle below 20% I think

MOAR PRECOOLAHS. That or a ramjet nozzle

Try again with a reactor. I realized it was alredy answered in the next page (this one). How do I delete this?

I think there is work alredy done for mH engines. Although I agree it wont be a really big deal, as these engines are basicly overthrusted NTRs. I guess it will help with TWR in super heavy launchers...

You can try and cover it in skin radiators, the trick works with supersonic heating, I havent tried re entry. What I meant is that you test if it survives re entry in particular and activate IgnoreMaxTemp. It heats up too much its weird... Maybe if you tweak its thermal mass in the confing...

Precoolers also work like radiators, and facing intake first at huge speeds and crazy small densities, its normal for it to be working in excess, and maybe doesnt realize its cooling nothing. In a nutshell: it looks like its a bug, test without precoolers to see if it survives, and if it does, ignoreMaxTemp

It works fine. You need a certain amount of pressure to overcome air pressure, if not, you just heat air in the best case scenario, and hot stuff recirculates into the cryotanks causing R.U.D. in the funniest case scenario (sadly not simulated in KSPIE). Anyway, going offtopic, if there isnt enough pressure (essentially thrust although not exactly proportional), its not gonna do anything. H2 gives basicly no thrust so you need a lot of power for it to work at low atmo, and its trash at launch vehicles, just use a denser, thrustier one.

try having them both of the same size and forget the fuel lines, not needed. In theory anything with ThermalPower should work. Do you have appropiate propellant and beam coverage?

A bit offtopic, but you spent a ton of science in it, wouldnt it be well done enough to not be suicidal? Also you have to be good to blow up a reactor, they usually malfuction when too hot. Unless its antimatter...

You spend 1000sci to create a conscious AI that cant pilot your ship but gives you a bit of science over time as if it was a lab You just go and hail your new machine overlord

You didnt have fuel (U233 in this case), LF is propellant (and the worst in the mod along with stock Oxidizer, change it to whatever else if possible). The fuel gives the geat and the propellant the remass, its mostly semantics XD The engine uses U and prop, so it may be that uses the same module as jet engines with IntakeAir and fuel, just a hypothesys

You dont have fuel XD Regarding the air for combustion thing, idk, but its NOT an air breathing engine, at all (sadly). Where does it ask for air, am I blind?

No real idea on who is causing the problem, but KSPIE (and all mods Ive recognized, about 2/3 XD) works in earlier versions, maybe its that?