While debate rages in the U.S. over drone surveillance of its citizens, drones were pressed into service over London on Saturday for a less contentious purpose: To promote the upcoming Star Trek movie. Ars Electronica Futurelab, an Austria-based media art lab, collaborated with German quadrocopter manufacturer Ascending Technologies to give Paramount Pictures publicity via "spaxel."

Thirty autonomous, LED-equipped "Hummingbird" drones took to London's evening skies, then self-assembled into the Star Trek logo, which then rotated as a whole. If that sounds simple, it sure ain't; Futurelab's software has to keep the drones from crashing into each other while they take off and find their positions, and the matter was complicated by both wind and snow, the former affecting the navigation and the latter affecting the drone-to-drone communication. Nevertheless, they were able to pull it off:

You can read more about how Futurelab and AT set this up here.