Complex sentence: In 2001, Shawyer founded "Satellite Propulsion Research Ltd", in order to work on the EmDrive, a drive that he claimed used a resonant cavity to produce thrust without propellant.
Split into simpler sentences: In 2001, Shawyer founded "Satellite Propulsion Research Ltd", in order to work on the EmDrive. He thought he could produce a drive that used a resonant cavity to produce thrust without propellant.