The first stage of a United Launch Alliance Delta II rocket moves into place in front of at the mobile service tower in Florida.

The first stage of a United Launch Alliance Delta II rocket moves into place in front of at the mobile service tower on Launch Pad 17-B at Cape Canaveral Air Force Station in Florida. The rocket will be raised to a vertical position and lifted into the tower. The rocket is the launch vehicle for the THEMIS spacecraft, consisting 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. After the first stage is in the mobile service tower on the pad, nine solid rocket boosters will be placed around the base of the first stage and attached in sets of three. THEMIS is scheduled to launch aboard the Delta II at 6:07 p.m. EST on Feb. 15. Photo credit: NASA/George Shelton