On a trip from Sylva to Desolo, I made an error and flew back to Sylva before I landed and then headed back to Desolo for a second time without landing. The solid-fuel thruster allowed me to do this, but then stranded me on Desolo as I had not visited yet and the thruster broke.
So I went Sylva -> Desolo -(without landing)-> Sylva -(without landing)-> Desolo -> A bad time
I believe this is a bug since the solid-fuel thruster is supposed to make 1 round trip but allowed 3 paths.