Christa McAuliffe

Late Space Shuttle Challenger teacher/astronaut Christa McAuliffe of Concord.

Divers from a documentary crew looking for the wreckage of a World War II aircraft off the coast of Florida found a 20-foot section of the space shuttle Challenger, which exploded and broke apart shortly after its launch in 1986, NASA said Thursday.

The divers contacted NASA after spotting a large, clearly modern object mostly covered in sand at the bottom of the ocean and bearing the shuttle’s distinctive tiles, the space agency said in a written statement.