The thing about glass ceilings is that there’s always one more to break. Even in 1999, or 16 years after Sally Ride became the first American woman in space, no woman had ever sat in the shuttle’s driver’s seat—commanding the mission from liftoff to wheels-down. That changed when Eileen Collins took Columbia aloft. The mission was noteworthy for what it accomplished scientifically—deploying the Chandra X-Ray Observatory, which greatly expanded astronomers’ view of the universe. But there was no mistaking the significance of who had the conn. Collins actually made similar history the first time she flew, in 1995, when she became the first female copilot. Her two other missions were in 1997 and, poignantly, in 2005—the return-to-flight mission after the extensive grounding that followed the loss of the shuttle Columbia in 2003. Collins did not ground herself until she at last retired from NASA in 2006.