Radar, or radio waves, sweep the sky every 12 seconds transmitting images of approaching aircraft that can then be viewed by controllers onscreen in a series of centers spanning the nation.

FORBES: Magazine Article

The ISS has suffered a series of glitches since Tuesday that left ground controllers with only tentative command.

CNN: Space tourist feels 'great' in orbit

He is justifying his behaviour first to Customer Dave and then to Mike Krahulik on that one day, in a series of emails between the morning (threatening to block Dave from cancelling and reordering the controllers) and late evening (threatening Penny Arcade with a smear campaign).

FORBES: Conclusion