Space Shuttle Columbia Disaster: Step-by-step graphic reveals exactly what went wrong during the fatal 2003 incident - and how it changed NASA forever

It's been just over 21 years since one of the darkest days in NASA's history. On the morning of February 1, 2003, Space Shuttle Columbia disintegrated as it reentered the atmosphere over Texas and Louisiana. The seven astronauts aboard – David Brown, Rick Husband, Laurel Clark, Kalpana Chawla, Michael Anderson, William McCool and Ilan Ramon – all lost their lives. The tragic event is being retold for a BBC Two documentary series airing from this week on BBC Two, 'The Space Shuttle That Fell to Earth'. MailOnline has revealed a step-by-step graphic showing exactly what went wrong on that fateful morning, which changed NASA forever.