Solid rocket boosters are clustered around the base of the United Launch Alliance Delta II rocket.

Solid rocket boosters are clustered around the base of the United Launch Alliance Delta II rocket. A total of nine will assist in the launch of the THEMIS integrated spacecraft. 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/Jack Pfaller