The covered Delta II second stage arrives at a checkout hangar on Cape Canaveral Air Force Station in Florida.

The covered Delta II second stage arrives at a checkout hangar on Cape Canaveral Air Force Station in Florida in preparation for transfer to Pad 17-B. At the pad, it will be lifted into the mobile service tower and mated with the first stage already in place. The Delta II is the launch vehicle for the THEMIS 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/George Shelton