Snapshots from Atlas 5 launch

A 12,000-pound Mexican mobile communications satellite was hoisted atop its Atlas 5 rocket today as crews finished assembling the vehicle for United Launch Alliance’s 100th liftoff next week.

In a major shakeup at NASA Headquarters, agency Administrator Jim Bridenstine said Wednesday that Bill Gerstenmaier, the widely respected director of human spaceflight, has been replaced in the midst of an ambitious push to meet the Trump administration’s directive to send astronauts back to the moon within five years.

Plans to launch a Navy communications satellite aboard an Atlas 5 rocket early Monday have been interrupted by Tropical Storm Erika, an unpredictable cyclone with its sights on Florida.