3 people have died in space till date; all in a 1971 mission
On June 30, 1971, the only deaths in space occurred when three Soviet cosmonauts were returning from first-ever space station Salyut-1. The crew was found dead on opening their space capsule despite a perfect automated landing. An investigation revealed a valve had ruptured during undocking from Salyut-1, which led to depressurisation and sudden death before the capsule entered Earth's atmosphere.