NASA is gearing up for an intense few weeks of work aboard the International Space Station, staging three spacewalks, moving a docking port from one module to another to support commercial crew ferry ships and capturing an Orbital ATK Cygnus cargo ship carrying nearly 4 tons of equipment and supplies.
The United Launch Alliance Delta 4 rocket, standing 217 feet tall and weighing 900,000 pounds, unleashes 1.8 million pounds of thrust from its main engine and four side-mounted boosters at 8:18 p.m. EDT Saturday (0018 GMT Sunday) to launch the ninth Wideband Global SATCOM satellite for U.S. military and allied communications.
The 330-foot-tall mobile service tower is rolled away from the United Launch Alliance Delta 4 rocket at Cape Canaveral’s pad 37B in the hours before the scheduled liftoff. The 9-million-pound gantry was retracted the length of a football field in preparation for launch of the Air Force’s WGS 9 communications satellite into Earth orbit.
The U.S. Air Force this week awarded SpaceX a contract to launch a Global Positioning System satellite in early 2019, concluding the second of as many as 15 competitions the military plans to run over the next year to pit SpaceX against United Launch Alliance for rights to lift defense and intelligence-gathering payloads into orbit.