Photos: Delta 4-Heavy with Orion on eve of launch

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 three-minute test flight Tuesday morning over Cape Canaveral will help ensure NASA’s Orion crew capsule — the vehicle being built to carry astronauts back to the moon — can safely escape from a catastrophic failure on launch.

NASA’s Orion spacecraft achieved all but two of 87 demo objectives on its first orbital flight last month, but details on the capsule’s performance will require dismantling the spaceship’s outer skin in a careful procedure designed to keep most of the Orion prototype intact for future testing.