Engineers have unveiled the latest prototypes for a European rover that is due to land on Mars in 2015.
BBC News has had exclusive access to the test vehicles which are being put through their paces by space company UK Astrium at its HQ in Stevenage.
The British team on this European Space Agency (Esa) project has nicknamed the prototypes Bruno and Bradley.
The six-wheeled robots are claimed to be the most robust and manoeuvrable planetary rovers to be built.
According to Chris Draper, Astrium’s ExoMars rover vehicle industrial manager, they can go literally where no rover has gone before.