Apologies for the late response, work has been getting in the way lately... but thanks for the help! Your response resolved my issue and makes sense! Also appreciate all the time and effort you have put into this MOD, really opens the door to do some really cool stuff in KSP. Plus it's a fun platform to learn python and a good use for my raspberry pi. I'm currently working on a Mun landing script and one of the critical data streams is the ships vertical speed. The following code is attempting to setup a stream to access my vertical speed and is based off the syntax used to setup the altitude (which is also from the flight class). Unfortunately the current setup always returns 0 for my vertical speed. I belive i am making the correct class call but not sure why it's always zero... Vertical_Speed = conn.add_stream(getattr, vessel.flight(), 'vertical_speed') print ('\nVertical Speed = %d' % Vertical_Speed()) Thanks,