Gemini Lander Engine is good, but very low-thrust. Makes it all but useless on bodies that aren't moons, even when using many multiples of the engine.
I have two wishes for engines that I haven't found yet:
- High-thrust, much larger version of that Gemini engine for landing heavy payloads and also for deep-space heavy-payload maneuvers. There is one high-thrust hypergolic engine in the game but it can only be fired once and no throttle. The only other real option is the Apollo Service Engine but it is unthrottleable and the thrust is still very low for heavy payloads (anything bigger than an Apollo mission), so there isn't really any option for manned deep-space missions right now.
- Super-high-thrust 1st-stage engine - something as big and powerful and expensive as 20x F-1A's, for launching really big payloads. The lag from huge numbers of F1's right now makes it impossible to launch very large vehicles like this. Would love to see something like the Sea Dragon Rocket engine made compatible with RO.
Are there any 3rd-party options compatible with Real Fuels for either of these scenarios?
Also, I can't get the NERVA to work properly. I understand it has limited use cases, but its Isp in practice seems to be closer to 250 in a vacuum rather than the claimed 900+, at least according to Kerbal Engineer when building the vehicle. I can't find any usage scenario - even high-dV - where it would outperform any conventional engine. And I wish it allowed fuels other than Hydrogen, like real nuclear engines (they are flexible in fuels), so they could be used with less/no boiloff for deep space maneuvers (the only scenario they should be useful for, anyway).
And one last thing... the ion engine is useless. The RO wiki suggests using it in conjunction with the Orbit Manipulator mod, but that mod doesn't seem to exist anymore for recent versions of KSP, making the engine unusable.
