RO/RP-1 Engines not thrusting

[Micah Gallantz]

Hi, 

I have somewhat recently begun using KSP with Real Solar System, Realism Overhaul, and Realistic Progression 1(As well as a the dependencies). It has been going well, and I am at the point that orbital launches are routine and reliable. But, then all my upper stages stopped working. I separate from the booster, and it can go one of 2 ways: 1. the decoupler goes off, but the second stage does not move. RCS engines make plumes but do not make any thrust. I try to ignite the Second stage engine, and the plume starts up, but it does not make any thrust. The other thing that sometimes happens, is that the decoupler separates,  and the RCS thrusters work and ullage the rocket, but when I ignite the engine, the same thing happens with a plume but no thrust. I have tried this on 2 different second stages, different engines, different boosters, and I have reinstalled RO engines, but the same thing happens. Can anyone help with this? Am I not Ullageing enough? Is one of the mods not working?

[jimmymcgoochie]

Can you provide a video of the problem? Or if not, some screenshots of the rocket at the point where the stage separates, with the PAW (right click menu) for the second stage engine pinned open. Which engines have you tried?

Check your MechJeb settings to ensure that you have ‘prevent unsafe ignitions’ on so that engines only start when 100% ullaged, and that you’re using the right propellant mix for each engine or RCS thruster. Check your avionics limits too, if your rocket is too heavy for the avionics then you won’t have control.

It might be worth getting the most recent master branches of RO and RP-1 from GitHub and installing those, as there might be a bug fix for the problem you’re having. If none of that helps, ask in the RO/RP-1 discord channel as you’re more likely to get help there than here on the forums.