Live coverage of the countdown and launch of a Virgin Orbit LauncherOne rocket. The air-launched rocket will climb into orbit with seven small satellites after release from a Boeing 747 carrier aircraft southwest of Los Angeles. Text updates will appear automatically below. Follow us on Twitter.
EDITOR’S NOTE: Virgin’s live webcast begins at 5:30 a.m. PDT (8:30 a.m. EDT; 1230 GMT).