Nasa’s hunt for signs of life on Mars divides experts as mission costs rocket

The soaring price-tag of a plan to fly rock samples back to Earth is jeopardising other space projects, say critics

It is one of the most complex space missions ever contemplated. A flotilla of unmanned probes and robot rovers will be flown to Mars to gather rock samples which will then be blasted back to Earth for study for signs of life.

This is Nasa's Mars Sample Return and it would involve the first-ever space launch from another planet, as well as the first-ever rendezvous in orbit around another planet.