It's been 25 years since the seven astronauts died when the Challenger Space Shuttle exploded shortly after liftoff. The accident occurred on January 28th 1986 just 73 seconds into the flight. Killing the entire crew, including school teacher Christa McAuliffe.

Families of the Challenger crew, former astronauts and NASA officials gathered Friday morning for a memorial held at the Kennedy Space Center in Florida. Yahoo News reports that:

Speakers at Friday's ceremony included the widow of Challenger's commander, June Scobee Rodgers, who was instrumental in establishing the Challenger Center for Space Science Education. The 48th learning center opens Friday in Louisville, Ky.

"The entire world knew how the Challenger crew died," she said. "We wanted the

world to know how they lived and for what they were risking their lives."

The memorial was held at the Space Mirror Memorial, which is a granite monument bearing the names

of all 24 astronauts who have died in the line of Duty.

The other Challenger crew members included Dick Scobee, Michael Smith, Ellison Onizuka, Judith Resnik, Ronald McNair and Gregory Jarvis.