Despite their long-standing differences during the Cold War, in 1975 the US and USSR embarked on a joint mission into space.
The aim of the operation was to dock an American Apollo space capsule with a Soyuz one made by the Soviet Union.
The collaboration took place at a time when it looked like diplomatic relations between the two sides were starting to improve.
Millions of people watched a live feed of the rendezvous as it happened 200km above the earth.
Written and produced by Nick Holland.
- Witness History: The stories of our times told by the people who were there.
This article was originally published by Bbc.co.uk. Read the original article here.