United Launch Alliance teams have started the countdown for launch of an Atlas 5 rocket Thursday from pad 41 at Cape Canaveral Air Force Station with NASA’s Mars 2020 Perseverance rover. The two-hour launch window opens at 7:50 a.m. EDT (1150 GMT).

LIVE COVERAGE: https://spaceflightnow.com/2020/07/28/atlas-5-av-088-mission-status-center/