We've all seen images of astronauts in their spaceship cabins at zero gravity. Moving freely through the interior space, nothing inhibits them but the insubstantial friction of the air. Now imagine that they are repelled by the cabin walls. Instead of freely floating around, the hapless space travellers would be pushed to the place that is farthest away from all the walls. There they would be stuck, captured in a repulsive trap. Reporting in this issue (page 692), Krishnan et al.1 describe the realization of this scenario at the nanometre scale: an electrostatic trap for nanoparticles.