Watch live as NASA announces astronaut crews for new U.S. spacecraft

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.

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.

SpaceX has filed a protest challenging a nearly $150 million NASA contract awarded to United Launch Alliance last month to send a robotic asteroid probe into space.