On 28 January 1986, the space shuttle Challenger disintegrated just 73 seconds into flight, with the loss of all seven astronauts on board. One of them was Christa McAuliffe, a teacher from New Hampshire who beat 10,000 applicants to be selected as the first person to fly to space not from Nasa. This documentary explores the reasons behind the tragedy, through the personal testimony of the crew's families and colleagues, and the engineers who were working behind the scenes