On Pad 17-B at Cape Canaveral Air Force Station, workers attach an overhead crane to the Delta II second stage in order to raise it to vertical. 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.