1. Episode 1

As Nasa prepares space shuttle Columbia for its 28th mission, excitement and trepidation build amongst the astronauts and their families. But a month before they are due to launch, Nasa grounds its entire shuttle fleet when cracks are discovered in the fuel lines.

3. Episode 3

Sixteen minutes from landing, mission control lose contact with the crew. The fears of some Nasa engineers are coming true. Following the disaster, Nasa comes under pressure to give answers.