After clocking 328 consecutive days in space, NASA astronaut Christina Koch landed safely back on Earth the week before last. Her trip was the longest-ever single spaceflight mission for a woman, and she did it for science: NASA needs to study the long-term effects of spaceflight on the human body in preparation for eventual stays on the Moon and missions to Mars. Bodies, see, they’ve gotten kind of used to functioning in a gravity-based environment, and when they’re transported to microgravity or zero g’s, things get out of whack. Your heart beat changes because your ticker blorbs into a sphere, your eyes change shape making your vision worse and your body generally goes catawampus due to the lack of gravity. One of Christina Koch’s main experiments was focused on bone health and why vertebrae tend to break after long duration flights; this kind of high-level (so to speak) guinea pig work could help doctors keep future astronauts healthy. This week we are going to float around with Koch and her pal and crewmate, Jessica Meir. Don’t forget your helmet!