[guepe]

Ah! That “well” is exactly what I couldn’t understand from ion thrusters, where they shed electrons as they expulsé ionized gas. All I could find was “to keep the same charge”, but since there is no absolute ground, what’s the problem?

You just explained it :)

[sbdhzjd]

Np. I remember first coming to that realization.

Fun thought experiment: what happens to a beta emitter in outer space?