A British-led space expedition will this weekend complete a revolutionary landing craft that could finally prove the existence of life on Mars. Technicians working on the ambitious project, branded mission impossible when it was first proposed in 1997, are expected to complete final preparations on the Beagle 2 lander following just two years of development. A collaborative effort between a consortium of univer sities, research support units and industry, the team’s leaders are confident the spectacular launch will restore the UK’s reputation as a leading light of scientific discovery.