Live coverage: Atlas 5 countdown and launch journal

This is the launch timeline to be followed by the Atlas 5 rocket’s ascent into orbit from Cape Canaveral with the SBIRS GEO Flight 3 satellite for U.S. military infrared reconnaissance. Launch is scheduled for Thursday at 7:46 p.m. EST (0046 GMT).

The Airbus-built Solar Orbiter spacecraft has been closed up inside the payload fairing of a United Launch Alliance Atlas 5 rocket in preparation for liftoff from Cape Canaveral in February on a joint mission between the European Space Agency and NASA.

United Launch Alliance will need to lure commercial customers to ensure the economic viability of its new Vulcan rocket, which is set to debut in 2019 just as the rate of U.S. military satellite launches is due to take a dip.