Mars Sample Return is billed as the most complex and costliest exploration of Mars ever conceived.

Once samples are on Earth, laboratories will be able to extract more data than by remote control using, for example, a robotic rover on the Martian surface.

A working group has come up with a mission profile and flight design.

The report's authors said that, regardless of the start date, it would take five years for the precious 500g (1.1lb) sample to be returned to Earth, and the world's major space powers had to pool resources to achieve the extraordinary goal.