At Astrotech Space Operations technicians guide one of the THEMIS probes into position on the probe carrier.

At Astrotech Space Operations, technicians guide one of the THEMIS probes into position on the probe carrier. When all five probes are in place, the carrier will 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. Photo credit: NASA/George Shelton