Monkeys may become the first earthlings to set foot on Mars.

A troop of 40 macaque monkeys are being groomed at the Sochi Institute of Medical Primatology, at Vesyoloye near the Black Sea, to undertake a journey to the red planet, ahead of a human mission.

''People and monkeys have approximately identical sensitivity to small and large radiation doses,'' the institute's director Boris Lapin told the BBC, and added it was better to experiment on the macaques rather than on dogs or other animals.

The macaques will be the first to experience the radiation that poses cancer risk to astronauts if they spend too long in space.

Scientists at the Russian institute will monitor the reaction of the macaques to weightlessness, isolation, a special diet of pureed food and radiation, which are considered a major hazard for astronauts flying to Mars.

Russia first sent macaques into space in 1983, but the flights ended when funding was cut in 1996. The Mars mission is however, not expected to take place for another decade.