# Space Planes You can “skip” off of the atmosphere a few times at hypersonic speeds ### Questions * Why have military prototypes of this failed/not happened * Contra [[Reusable Rockets]] [Web URL for this note](http://notes.benjaminreinhardt.com/Space+Planes) [Comment on this note](http://via.hypothes.is/http://notes.benjaminreinhardt.com/Space+Planes)