The astronaut ends a 25-year career after his last mission saw him spend much longer than expected on the ISS.

The astronaut is stepping away from NASA shortly after returning from a troubled test flight that left him aboard the ISS months longer than expected.

Wilmore, 62, had already retired from the Navy. Williams, 59, also a retired Navy captain, is still with NASA. She joined Second Lady Usha Vance at Johnson Space Center in Houston earlier this week, taking part in a summer reading challenge for schoolchildren.