Q&A with Tory Bruno, ULA’s chief executive

The last flight of United Launch Alliance’s Delta 4-Medium rocket lifted off Aug. 22 from Cape Canaveral Air Force Station in Florida, riding more than 1.2 million pounds of thrust from a hydrogen-fueled main engine and two strap-on solid rocket motors.

This is the ascent timeline to be followed by the Atlas 5 rocket’s ascent into orbit from Vandenberg Air Force Base in California with the commercial WorldView 4 Earth-imaging satellite for DigitalGlobe. Launch is scheduled for Friday at 11:30 a.m. local time (2:30 p.m. EDT; 1830 GMT).

A package of communications and tech demo satellites for the U.S. Air Force rode a United Launch Alliance Atlas 5 rocket into an orbit more than 20,000 miles over the equator after liftoff from Cape Canaveral Saturday evening.