At Astrotech Space Operations, one of the five THEMIS probes is lifted from a scale. It will be moved to a probe carrier for installation, along with its four mates, and then undergo spin-balance testing. THEMIS consists of five identical probes, the largest number of scientific satellites ever launched into orbit aboard a single rocket. This unique constellation of satellites will resolve the tantalizing mystery of what causes the spectacular sudden brightening of the aurora borealis and aurora australis - the fiery skies over the Earth's northern and southern polar regions. THEMIS is scheduled to launch Feb. 15 from Cape Canaveral Air Force Station.