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.

Astronaut and University of Tennessee graduate Barry "Butch" Wilmore has announced his retirement from NASA. The news comes months after he and fellow Astronaut Suni Williams returned to Earth from a nine-month stay aboard the International Space Station that made world news.

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.