Mars500 simulation crew in 'spacewalk' in Moscow sandpit
Two men wearing spacesuits have walked across a sandpit at a Moscow institute in a simulation of a mission to Mars.
The pair - both volunteers - have spent eight months with four other men locked away in a series of windowless steel tubes representing a spacecraft.
The Mars500 project is trying to find out how the human mind and body would cope on a long-duration spaceflight.
Russian Alexander Smoleevskiy and Italian Diego Urbina planted flags on their pretend planet.
One flag was for Russia, another for China and a third for the European Space Agency (Esa).
They then undertook some virtual experiments with the assistance of a robot rover, with the whole activity lasting an hour and 12 minutes.