Why two astronauts are stuck in space

Nearly two months after launch and almost 50 days after they were initially supposed to return to Earth, two astronauts stuck at the International Space Station finally appear to be closer to their homeward voyage. That they were trapped by troubles with their Boeing Starliner spacecraft has only raised fresh doubts about the company’s technological and engineering capabilities as it weathers several major scandals.

The two astronauts who made the journey on the Starliner, Barry “Butch” Wilmore and Sunita “Suni” Williams, have been at the ISS longer than initially intended,...