Live coverage: Delta 2 launches

SpaceX has pushed back the liftoff of a Bulgarian television broadcast satellite on the company’s second previously-flown Falcon 9 rocket until at least Friday, giving ground crews time to replace a valve on the launcher inside a hangar at its Florida launch pad.

Less than three months after rocketing into space, the commercial WorldView 4 Earth-imagery satellite has finished in-orbit testing and calibration to begin operations for DigitalGlobe.

Three fresh crew members lifted off at 1541 GMT (11:41 a.m. EDT) Friday on a six-hour trip to the International Space Station, riding a Soyuz spaceship from the Baikonur Cosmodrome in Kazakhstan. The trio hails from Russia, the United States and Italy and boosted the station’s crew back to a full complement of six. Docking occurred at 2154 GMT (5:54 p.m. EDT).