Video: Orion flight highlights

The booster rocket that will launch NASA’s next-generation Orion space capsule on a two-orbit, four-hour shakedown cruise in December has been rolled to the launch pad at Cape Canaveral.

United Launch Alliance called off the planned liftoff of a Delta 4-Heavy rocket and a classified National Reconnaissance Office spy satellite from Vandenberg Air Force Base in California on Wednesday after indications of elevated hydrogen concentrations around one of the launcher’s main engines. Three previous launch attempts were scrubbed by technical concerns and bad weather.