How is the mass discharged?
A space qualified charge control system, similar in concept to the proposed STEP system, has been built for GP-B. Essentially it shines an ultraviolet light into the gap between the mass and its housing, creating a cloud of free electrons from both surfaces. A small steering voltage on nearby electrodes causes the electrons to move on or off of the mass. This current is used for discharge, and is much larger than that expected from particle radiation.
