Photos: Atlas 5/MMS launch gallery

A $1.8 billion U.S. Air Force communications satellite rode a United Launch Alliance Atlas 5 rocket into orbit Wednesday from Cape Canaveral, joining three similar craft perched more than 22,000 miles above Earth to ensure government leaders can remain in contact with military commanders in the worst-case scenario of nuclear war.

Crew Dragon commander Mike Hopkins, pilot Victor Glover, and mission specialists Shannon Walker and Soichi Noguchi flew to the Kennedy Space Center on a NASA-chartered private jet Sunday, ready for a final week of training, refresher courses, and some time off before their launch to the International Space Station.

Vaulting away from Cape Canaveral on an unusual southerly trajectory, a Falcon 9 rocket dodged stormy weather and successfully placed an Argentine radar observation satellite into an orbit over Earth’s poles Sunday on SpaceX’s 100th launch.