NASA is remembering the seven astronauts killed 13 year ago today on the space shuttle Columbia.

Monday wraps up a week of tributes to the astronauts who sacrificed it all in the name of space exploration.

On Feb. 1, 2003, Columbia was returning to Earth, set to arrive at the Shuttle Landing Facility after a 16-day scientific mission.

Family, friends and the media were all eagerly awaiting Columbia’s arrival.

But as Columbia re-entered the Earth’s atmosphere, it broke apart. Pieces of the shuttle could be seen streaking over the Texas sky. The seven astronauts on board were killed.

NASA later determined that the left wing of the shuttle was damage during launch, and the damage caused the spacecraft to disintegrate as it returned to Earth.

The Columbia disaster marked the beginning of the end of the space shuttle, which was retired in 2011.