NASA and the families of the crew decided to preserve its wreckage, which now sits on the 16th floor of the massive Vehicle Assembly Building at Cape Canaveral. For scientists, it's a "treasure trove" that lets them study the material used in the spacecraft, said Mike Ciannilli, the caretaker of the orbiter's remains.

And for young NASA workers, it's a place to see firsthand why failure can't be an option.

"When you actually walk amongst Columbia and you talk about the accident and you talk about the lessons learned and how you can do the best job you can do to help prevent this from ever happening again, that's very powerful," Ciannilli said.