Space elevators are touted as a cheap alternative to rocket propulsion for transporting cargo and even people into orbit. So far, they exist only on paper, but ultimately robots could climb a cable stretching thousands of kilometres from Earth’s surface into space.
However, there is a hitch: passengers could be killed by the radiation they receive on the way to the top, say Anders Jorgensen and Steven Patamia at Los Alamos National Laboratory in New Mexico, and Blaise Gassend of the Massachusetts Institute of Technology. At the proposed speed of 200 kilometres per hour, passengers would spend a few days in the Van Allen radiation belts,…
