When scientists sent the first humans careening into the vacuum of space, they had no idea what food would do to a body in orbit. Could a person swallow while in weightless flight? Does digestion even work without gravity? In 1961, Russian cosmonaut Yuri Gagarin quelled this fear by successfully swallowing and digesting a paste of beef and liver. That same year, cosmonaut Gherman Titov ate crackers while orbiting Earth. A few months later, American astronaut John Glenn sucked 80 calories of applesauce from an aluminum tube. No doubt Gagarin, Glenn, and Titov would envy the diets of astronauts living on the International Space Station today—they recently got to chow down on tacos for dinner, using fresh chili peppers grown in orbit.