Forty years ago this January, the Space Shuttle Challenger disintegrated on its way into orbit. All seven astronauts on board were killed.

In the days after the tragedy, the world wanted answers. What really caused the shuttle to explode? And should the launch have been stopped altogether?

For season five of Science Friction, Dr Karl Kruszelnicki and Fiona Pepper investigate how the Challenger disaster unfolded — and what that has meant for space exploration from 1986 to now.

The Challenger Legacy is a five-part series from Science Friction. Out NOW — search Science Friction and The Challenger Legacy.