Yep. Vacuum is an excellent insulator, so you can build up quite an impressive charge. This is a serious concern for spacecraft and astronauts, especially those operating in low Earth orbit where they interact with the Earth's ionosphere (the tenuous upper reaches of the atmosphere, comprised of charged particles). There are experiments on board the ISS to study the electrostatic environment around the ISS to better understand this risk and work out how to cope with it. <div class="Discussion_UserSignature"> <p> </p><p><font color="#666699"><em>"People assume that time is a strict progression of cause to effect, but actually from a non-linear, non-subjective viewpoint it's more like a big ball of wibbly wobbly . . . timey wimey . . . stuff."</em> -- The Tenth Doctor, "Blink"</font></p> </div>