What concerns are keeping Starliner astronauts from returning to Earth?

NASA has a plan to bring back Butch Wilmore and Suni Williams, the two astronauts who took the troubled Boeing Starliner to the International Space Station, but it means they'll need to stay in space another six months. Wilmore and Williams are now slated to return on a SpaceX capsule in February, extending what was supposed to be a week-long mission to more than eight months. CBS News space consultant Bill Harwood has more on what issues are keeping Wilmore and Williams from returning.