Development and Validation of a Canfield Joint as a Precision-Pointing System for Deep Space Instrumentation Figure 7. Illustration of the Canfield prototype with labeled components (top) and mass study illustration showing overall dimensions in inches (bottom). Image credit: Balcones Technologies. Figure 6. Prototype with open-loop superstructure. uous rotation without the need for failure-prone and costly slip rings or rotary joints typically found in conventional gimbal arrangements. The resulting three-degree-of-freedom device is capable of continuous full hemispherical plus FOR without keyholing and superior size, weight, and power characteristics. In addition to communications peripherals, the Canfield joint has been explored for pointing of directional thrusters [22]. MASS SAVINGS Since cables may be routed through the center of the Canfield joint rather than around it, the system eliminates the bulky cable management trays and extended wire looms necessary for conventional rotational gimbal systems, offering significant mass savings for the integrated system. The MRO spacecraft is an example ofhow a cable tray adds significant mass to the overall pointing system: the gimbal apparatus used to direct the high-gain antenna, shown in Figure 8. Illustration of the test setup used. As the Canfield joint was moved, the position ofthe laser dot on the quadrature detector changed. The dot's position provided an error signal for the controller, as shown in Figures 10 and 11. 26 IEEE A&E SYSTEMS MAGAZINE JULY 2022