On Friday, Boeing and United Launch Alliance conducted a number of key tests in preparation for the launch of the Starliner spacecraft later this month.

During this “Integrated Day of Launch,” flight controllers in Houston and Florida monitored data as the spacecraft and its United Launch Alliance rocket practiced fueling as if the booster were about to launch. During this test, the Atlas V rocket was loaded with propellants, and the countdown was taken to the final second at Cape Canaveral Air Force Station.

Boeing and United Launch Alliance said this wet dress rehearsal was successful and that they remain on track for a December 20 launch. This Starliner uncrewed mission is a precursor to a flight with astronauts that will follow several months later.