The United Launch Alliance Delta IV port booster is being mated to the core booster inside the Horizontal Integration Facility.

The United Launch Alliance Delta IV port booster is being mated to the core booster inside the Horizontal Integration Facility at Space Launch Complex 37 on Cape Canaveral Air Force Station in Florida. The Delta IV Heavy rocket will launch an uncrewed Orion spacecraft on Exploration Flight Test-1.

During the mission, Orion will travel farther into space than any human spacecraft has gone in more than 40 years. The data gathered during the flight will influence design decisions, validate existing computer models and innovative new approaches to space systems development, as well as reduce overall mission risks and costs for later Orion flights. Liftoff of Orion on the first flight test is planned for December 2014. Photo credit: NASA/Ben Smegelsky