Cape Canaveral, Florida
Twenty-five years ago, seven astronauts died aboard space shuttle Challenger when it exploded shortly after liftoff.
NASA officials will gather at Florida's Kennedy Space Center on Friday morning to mark the somber anniversary. Special guests include the widow of Challenger's commander, June Scobee Rodgers.
She'll be the featured speaker at the outdoor ceremony. Her husband, Dick Scobee, died along with his six crewmates on Jan. 28, 1986. Schoolteacher Christa McAuliffe was among the dead.
Rodgers was instrumental in establishing the Challenger Center for Space Science Education.
The ceremony will take place at the Space Mirror Memorial, a granite monument bearing the names of all 24 astronauts who have died in the line of duty.