Photos: Delta 4 lights up the sky for night owl launch

Days after SpaceX opened preorders for Starlink internet service, two more Falcon 9 rockets are set to launch from Florida’s Space Coast as soon as Sunday night and Wednesday morning — weather permitting — to help push the network closer to commercial operations.

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.

Boeing’s Starliner capsule, carrying an instrumented astronaut test dummy nicknamed “Rosie,” is on track for launch Friday on an unpiloted test flight to the International Space Station, mission managers said Tuesday. The flight is a major milestone in NASA’s push to resume launching U.S. crews from American soil.