Two seasoned NASA astronauts, with a total of 500 days of prior space travel experience, were the initial crew to be launched into space aboard Boeing's Starliner space capsule during a test flight on June 5 from Florida. Originally, they were set to return after approximately eight days. However, Barry 'Butch' Wilmore and Sunita 'Suni' Williams, both ex-military test pilots, are now scheduled to return to Earth early next year via a SpaceX vehicle. NASA has deemed the propulsion system issues with the Starliner too risky for the crew's planned return.

The Starliner capsule experienced leaks and some of its thrusters malfunctioned, leading to an extended mission at the International Space Station by several months. Here are additional details about the astronauts:

Wilmore, 61, a retired US Navy captain, has completed four operational deployments, flying fighter jets from aircraft carriers, including 21 combat missions during the first Gulf War in the 1990s. He also served as a Navy test pilot and flight instructor before joining NASA's astronaut corps in 2000. Wilmore first visited the space station as a NASA space shuttle pilot in 2009 and returned in 2014 aboard a Russian Soyuz spacecraft for a long-duration mission, serving as station commander for several months. Prior to his Starliner mission, Wilmore had accumulated 178 days in space and conducted four spacewalks. A Tennessee native and former college football player at Tennessee Tech University, Wilmore holds advanced degrees in electrical engineering and aviation systems. He is married with two daughters.

Williams, 58, a former Navy helicopter pilot who has flown over 30 different rotary aircraft, was deployed during the first Gulf War as part of a helicopter combat support squadron. She later supported Navy disaster relief efforts in Florida after Hurricane Andrew. Williams returned to the naval test pilot school as a rotary aircraft instructor before being selected for NASA's astronaut program in 1998. Similar to Wilmore, she first traveled to the space station aboard a space shuttle and later returned as a Soyuz passenger. Both of her ISS missions, in 2006-2007 and 2012, were long-duration scientific expeditions. After two stays at the outpost, Williams held the world record for the most time spent by a woman in orbit outside a spacecraft, totaling 50 hours and 40 minutes over seven spacewalks, a record later surpassed by astronaut Peggy Whitson. During her second ISS mission in 2012, Williams became the second woman to command the station. An avid athlete, Williams was the first person to complete a marathon in space in 2007 and later the first to complete a triathlon in space in 2012. Before her Starliner mission, Williams had spent a total of 322 days in space and made history as the first woman on the inaugural crewed flight of a new orbital spacecraft. Born in Massachusetts, Williams currently lives in Houston with her husband, a federal police officer and former helicopter pilot.