How Space Travel Literally Turns Astronauts Into Time Travelers

4. The International Space Station’s Speed

Orbiting Earth at an astonishing 28,000 km/h, the International Space Station (ISS) is a real-world laboratory for time dilation. Astronauts aboard the ISS experience time just a little more slowly than we do on the ground. Over the course of long missions, this difference adds up to mere milliseconds—but it’s a measurable effect! Learn more at ESA.