A satellite propulsion system which includes a 3D printed titanium piston, the MPS-120 is designed with a chassis is not much bigger than a coffee mug. Aerojet Rocketdyne just completed a hot-fire test of the MPS-120 CubeSat High-Impulse Adaptable Modular Propulsion System this week, and it's the first 3D printed, hydrazine integrated propulsion system. It's designed to provide propulsion for tiny CubeSats. You can read all the details about the project here: http://3dprint.com/31305/titanium-3d...pulsion-system