Nasa funds the power beaming competitions to power the climbers up the future space tether, right. Why can't they just transmit the power through the cable itself? If need be they could send it positive one way and have a parrallel cable being negative, with an insulator in between, right? remember carbon nano tubes are conductive right? It seems like the obsticles to such a system (the van Allen Belts) could be easily overcome, right?