Which beast provides the greatest number of calories for the lowest launch weight and feed consumption? To serve beef to two or three Mars astronauts, “a steer of 500-kilogram body weight has to be hauled into space.” Whereas the same number of calories could be derived from just 42 kilograms of mice (about 1,700 of them). “The astronauts,” stated the paper’s conclusion, “should eat mouse stew instead of beef steaks.”
