Photos: Falcon 9 launch from Press Site

The last unflown variant of United Launch Alliance’s Atlas 5 launcher — fitted with a five-meter fairing and a single strap-on solid rocket booster — will carry a pair of U.S. military space surveillance satellites toward geosynchronous orbit from Cape Canaveral late this year, according to a Space Force spokesperson.

A SpaceX Falcon 9 rocket arrived at launch pad 39A on Florida’s Space Coast on Sunday, a day before liftoff with a powerhouse Inmarsat communications satellite designed to spread broadband beams connecting airline passengers, maritime crews and U.S. and international military units with Internet and data services.

This video captures the final portion of the launch countdown and follows the Atlas 5 rocket’s flight through arrival in the preliminary orbit carrying the Curiosity rover headed for Mars. (Membership Required)