Episode 4

The work of the rocket scientists at the University of Surrey Space Centre, who are researching how to remove the hundreds of thousands of space junk orbiting the Earth's atmosphere at 17,000mph, which could do catastrophic damage if they were to collide with a satellite. Also, a specialist waste disposal team tackles asbestos which, despite being banned more than 20 years ago, remains the leading cause of occupational death in the UK, and glass thrown into a bottle bank is recycled as a jam jar.