CST-100 Starliner launch preparations, December 2019. United Launch Alliance Atlas V rocket being prepared to launch the Boeing CST-100 Starliner spacecraft from Cape Canaveral Air Force Station's Space Launch Complex 41, Florida, USA. The rocket's booster and Centaur upper stage are being filled with propellants for a launch rehearsal. This uncrewed Orbital Flight Test is part of the Crew Space Transportation (CST) programme. It launched on 20 December 2019 on Starliner's maiden mission to the International Space Station (ISS), part of NASA's Commercial Crew Program. The mission is intended to test the system's capabilities. Photographed on 5 December 2019.