Tributes to fallen astronauts dwell throughout NASA.
Trees bear names of the dead outside the Johnson Space Center in Houston. Inscribed plaques of missions that met tragedy hang on the walls inside conference rooms. At Cape Canaveral, a mirrored monument elevates into the sky the name of every astronaut who died venturing into space.
Even after decades, these astronauts’ presences linger, along with the lessons that their deaths taught the …