NORFOLK, Va. (AP) — High school students in Virginia got to learn about the challenges of life in microgravity directly from an American astronaut aboard the International Space Station.

Astronaut Drew Feustel spoke to students visiting NASA’s Wallops Flight Facility on Virginia’s Eastern Shore on Thursday using a video link. It’s part of an effort to boost interest in science, technology and math.

Feustel has been on the space station since March. He says sleeping is difficult because he never feels like he’s lying down. When he eats, it feels like food is floating in his upper chest. Showers are impossible because water doesn’t fall like it does on earth.

But Feustel says it’s worth it. The space station’s fundamental mission is preserving human civilization.