* Sorry bad english *
Hello, nice to see this mod revived. I don't play with it since the original author abandoned it so today I'm trying it out for the first time.
Unfortunately I'm having some issues that have already been commented by other people here. The Ranger battery is drained very, very fast. I have to set a very low thrust to be able to fly it for a long period of time, but can't make an orbit.
Problems with Lander too. It tends to point down, so I'm also unable to fly it at full thrust. By the way, the model seen from the back is not very accurate: https://www.dropbox.com/s/84gwubajmugnxux/LanderComparation.png?dl=0 (the KSP screenshot is not deformed, Landers engines are actually modeled with egg shape... I suppose that by mistake)
Tested with no other mods (just ModuleManager.2.6.25).
Log file: https://www.dropbox.com/s/eiksctaut167e2z/KSP.log?dl=0
Also, something that I always wanted to propose: Ranger engines should not work like RAPIER engines. As the Interstellar wiki says (http://interstellarfilm.wikia.com/wiki/Ranger), the Ranger has electric air jets (powered by twin miniaturized tokamak fusion reactors) wich enables the Ranger to propel itself through a planetary atmosphere. When there's no atmosphere, it uses chemical rockets which exhaust is ionized into plasma and magnetically accelerated to very high velocities.
So, basically, could you make the Cooper engines to consume no fuel and not needing oxygen when in air breathing mode? and also delete the particle effects, as air jets obviously don't produce flames.