<4.605630>For the past five decades, diehard astronautics fanatics and casual observers alike have been fascinated by humans floating through space. We’ve modeled VMA trophies after them, used the concept as a plot in dozens of movies, and turned it into a summer-camp attraction for awkward tweens. But despite this interest in traveling through the galaxies like Sandra Bullock in Gravity, our reasons for sending people out into the abyss have always seemed kind of vague. Fortunately, the National Air and Space Museum is ready to explain spacewalks to those of us who glean our information more from pop culture than textbooks. “Outside the Spacecraft: 50 Years of Extra-Vehicular Activity” arrives at the Smithsonian museum in conjunction with the 50th anniversary of the first spacewalks and focuses on the work astronauts do when they’re outside the space shuttle, whether building the International Space Station or repairing the Hubble telescope. The exhibition also includes memories from some of the 200 explorers who’ve had the opportunity to explore space. It’s as cool as you think it is. The exhibition is on view daily 10 a.m. to 5:30 p.m., to June 8, at the National Air and Space Museum, Independence Avenue and 6th Street SW. Free. (202) 633-2214. airandspace.si.edu.