I am Jessica Jorgens, and I was an intern at Marshall Space Flight Center, NASA, for spring term 2020. My main project was creating a Canfield joint for gimbaled thrusters. Currently, spacecraft use 16 or more fixed-position air thrusters for direction changes in orbit; my project’s purpose was to decrease the number of thrusters and increase efficiency by creating a mounted thruster that can point in many directions. A Canfield joint consists of a top plate attached to three hinged servo arms that allow the mounted thruster to point in a full hemisphere of directions.
A gaming controller was programmed to move the servos in the canfield joints to point to any combination of twelve preset radial directions and three pitch angles. Our initial plan included building a final joint out of 3-D printed parts to decrease weight and allow for vertical mounting of the joint instead of just horizontal, but without access to a machine shop or proper tools due to the Covid-19 shutdown of NASA campuses, our work ended here. Just before being quarantined, we were able to gather supplies to work on the programming from home: one fully assembled prototype, the parts for a second, circuitry supplies, and a few hand tools.
While they still need adjustments, these Canfield mounted thruster prototypes can already decrease the number of mounted thrusters by three to one, increase directional accuracy, and increase overall efficiency of direction changes in orbit.