Question Spacecraft3 MAIN_THRUST - SL or Vac?

[mjanicki]

Hi, all. I'm in the process of modifying a Spacecraft3 style launcher and couldn't find an answer to my question in the S3 docs. Hopefully someone else might have some information.

For the MAIN_THRUST setting of this launcher I'm obtaining my values from Lockheed-Martin documentation. However, the manufacturer's specs list two values for thrust -- one value at Sea Level, the other in Vacuum. Does anyone happen to know which of these values would be more appropriate to use for the Spacecraft3 configuration?

Thanks very much.

-- Mike

 

[mjanicki]

Found an answer myself so thought I'd post the info in case anyone else is interested. My answer came from the Orbiter SDK docs when I looked up the definition of Vessel::CreateThruster()

From there it is apparent that max thrust is expected to indicate maximum vacuum thrust rating. Coupled with ISP and a reference pressure, it looks possible to setup just about any conditions desired for non-vacuum thrust. I don't believe Spacecraft3 is doing this when it defines thrusters so just max thrust in vacuum will suffice for my purposes.

I suppose I could monitor the vessel with Vessel::GetThrusterMax() to see what's happening at sea level, but for now it's useful just to know that I should be using max rated thrust in vacuum for the configuration.

Thanks to anyone who took an interest and I hope someone finds this answer useful.