NASA paid tribute to all the late astronauts who died over the years when it commemorated the 20th anniversary of the space shuttle Columbia tragedy.

NASA marked the 20th anniversary of the space shuttle Columbia tragedy with somber ceremonies and remembrances during its annual tribute to fallen astronauts on Thursday.

CAPE CANAVERAL, Fla. (AP) — NASA marked the 20th anniversary of the space shuttle Columbia tragedy with somber ceremonies and remembrances during its annual tribute to fallen astronauts on Thursday.

NASA marked the 20th anniversary of the space shuttle Columbia tragedy with somber ceremonies and remembrances during its annual tribute to fallen astronauts on Thursday.

Feb. 1 marks the 20th anniversary of the tragic accident of the space shuttle Columbia, which killed seven astronauts. NASA's Kennedy Space Center in Florida paid its respects to the crew and ...

NASA is marking the 20th anniversary of the space shuttle Columbia tragedy with somber ceremonies during its annual tribute to fallen astronauts.