There is a lot that Nasa’s Perseverance rover has on its to-do list. Flying helicopters is only a small part of it. The rover, fitted with seven cutting-edge instruments for analysing rocks, the atmosphere and weather, is ultimately searching for signs of past and present life on Mars. But it will not do it on its own. The Perseverance mission is only the first step in a much greater project. Using its small drill, Perseverance will excavate promising pieces of Martian soil and store them in small tubes on the planet’s surface for another rover to retrieve at the end of this decade.
When the capsule carrying the coveted Mars samples eventually hits the ground somewhere in the US in the early 2030s, it will be the beginning of an operation that has not been seen since the return of the earliest Apollo missions. Whatever microorganisms there might be in the tubes will never come out alive from a high-containment facility yet to be built somewhere within...