Remnants of the Space Shuttle Challenger, which exploded shortly after take-off in 1986, were found off the east coast of Florida.
The debris was discovered by a TV documentary crew that was looking for Second World War aircraft wreckage.
Instead, the divers found parts of the Challenger, which exploded 37 years ago killing all seven crew members on board.
“While it has been nearly 37 years since seven daring and brave explorers lost their lives aboard Challenger, this tragedy will forever be seared in the collective memory of our country,” Nasa administrator Bill Nelson said.
“For millions around the globe, myself included, January 28, 1986 still feels like yesterday.
“This discovery gives us an opportunity to pause once again, to uplift the legacies of the seven pioneers we lost, and to reflect on how this tragedy changed us.”
A major malfunction 73 seconds after lift-off resulted in the loss of Challenger and the crew on board.
An agency investigation later showed unexpectedly cold temperatures affected the integrity of O-ring seals in the solid rocket booster segment joints.
Some space shuttle programme employees had raised concerns when they noticed ice forming on the shuttle.
The spacecraft had waited overnight on a launch pad at the Kennedy Space Centre in Florida, where a cold front brought freezing temperatures.
Despite concerns, managers cleared the mission for the launch.
The mission was commanded by Francis Scobee and piloted by Michael Smith.
The other crew members on board were mission specialists Ronald McNair, Ellison Onizuka, Judith Resnik, payload specialist Gregory Jarvis and teacher Christa McAuliffe.
Nasa’s Columbia mission in 2003 also failed, killing seven astronauts on board. The spacecraft broke up on re-entry over the western US.
The History Channel documentary depicting the discovery of the Challenger debris is scheduled to air on November 22.
The episode will appear as part of a series about the Bermuda Triangle.