Monday marks a tragic anniversary in American history. The Space Shuttle Challenger exploded 33 years ago on January 28, 1986.

It happened just 73 seconds after liftoff from the Kennedy Space Center in Florida.

Seven astronauts died in a team that was different than any that had come before.

Christa McAuliffe, a New Hampshire high school teacher, had been chosen to go into space and teach lessons from the shuttle.

She, Hughes Aircraft Co. satellite engineer Gregory Jarvis and physicist Ronald McNair were on the lower deck of the crew cabin at lift-off.

On the upper deck were engineers Judith Resnik and Ellison Onizuka, the shuttle’s pilot Michael Smith and the ship’s commander, Dick Scobee.

It was the first flight for Jarvis and Smith. The rest of the crew, save McAuliffe, had all flown on shuttle missions before.

Investigators later determined that a rocket booster failure caused the fuel tank to ignite.

President Ronald Reagan, who was supposed to give the State of the Union Address that night, spoke to a stunned country about Challenger instead.

Quoting from a poem called “High Flight” by John Magee, Reagan said,

"We shall never forget them nor the last time we saw them, as they prepared for their mission and waved good-bye and slipped the surly bonds of Earth to touch the face of God."