
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.
More than 100 people gathered under a gray sky at Kennedy Space Center to remember not only Columbia’s crew of seven, but the 18 other astronauts killed in the line of duty. NASA’s two shuttle accidents account for more than half of the names carved into the black granite of the Space Mirror Memorial; plane crashes are to blame for the rest.