/technologies/sensor-technology/b/blog/posts/mit-researchers-3d-print-sensors-for-spacecraft-in-low-earth-orbitMIT researchers 3D-printed RPAs for orbiting satellites. These operate similarly to expensive semiconductor sensors. (Image Credit: MIT) MIT researchers developed 3D-printed plasma sensors , also called retarding potential analyzers (RPAs) for ...en-USTelligent Community 12