“You have arrived at your destination.” This phrase, delivered with robotic cadence, is familiar to anyone who uses satellite navigation systems to guide them on sightseeing strolls, cross-country road trips, and all manner of journeys from point A to point B. But what if your destination is literally out of …

NASA has announced that astronauts Barry Wilmore and Sunita Williams will return to Earth next February aboard SpaceX’s Dragon spacecraft. The announcement at a press conference today caps off months of speculation about the best plan to safely bring the astronauts home after malfunctions with their ride, Boeing’s Starliner capsule, …

When is it OK to kill an alien life-form? In the movies, the answer is usually pretty simple: It’s OK in self-defense, especially if it inspires a rousing speech about human exceptionalism. But in the real world, the choice is neither straightforward nor abstract. Many missions to neighboring worlds could, …

Everybody poops, including astronauts. In fact, the first picture Neil Armstrong ever snapped from the surface of the moon shows a jettisoned waste bag that may well contain poop. The Apollo crews left a total of 96 bags of waste, including urine and feces, across their six landing sites, which …