# Reactionless Drives Space engines that can produce momentum without expelling fuel [Quantum vacuum thruster - Wikipedia](https://en.wikipedia.org/wiki/Quantum_vacuum_thruster#:~:text=The%20Casimir%20effect%20is%20a,point%20energy%20of%20the%20vacuum.&text=Several%20scientists%20including%20White%20have,related%20%22dynamical%20Casimir%20effect%22.) <!-- #case-study/possible-gem --> [Web URL for this note](http://notes.benjaminreinhardt.com/Reactionless+Drives) [Comment on this note](http://via.hypothes.is/http://notes.benjaminreinhardt.com/Reactionless+Drives)