So we all know that there are lots of engineering processes that are made 100 times better by negligible gravity, and that certain engineering process need to be performed in a vacuum (electron beam welding comes to mind for some reason).
However, are there any processes that require an atmosphere, or at least significantly benefit from one? I'm only talking about vacuum v non-vacuum here, so micro-gravity is fine. Also I'm really only interested in processes the specifically relate to satellite/space vehicle construction. This is a pretty general question (which is bad I know! :/) so I'll try and pin it down a little more:
What processes are required to produce satellites/space vehicles that would directly benefit from a low gravity/microgravity environment but are significantly hindered by a vacuum?