With movies like The Martian gaining in popularity recently, scientists still have a few problems to tackle before a manned mission to Mars is possible. One of these problems is the huge amounts of radiation that astronauts would be exposed to on the surface of Mars. Since Mars lacks a strong atmosphere or magnetic field, its surface isn’t protected from harmful radiation like Earth’s is. The Curiosity rover is currently measuring radiation levels using a toaster-sized monitor on board. NASA has set a limit of no more than 3% chance of dying from radiation-induced cancer at a 95% confidence level before it will approve any manned mission.