Astronauts on the ISS appear to float weightlessly. But the space station is only 400 km above Earth - where gravity is still 90% as strong as on the surface!
If gravity is still pulling them down, why do they float? The answer reveals the true nature of orbits.
The Challenge: Weightlessness in Space
The International Space Station orbits at 400 km altitude, traveling at 7.66 km/s(27,600 km/h). At this altitude, g = 8.7 m/s^2 - still 89% of surface gravity! Yet astronauts experience apparent weightlessness. How?
Why do astronauts on the ISS appear weightless?
Try it! Understanding orbits and gravity is essential for satellite communications, GPS, and space exploration!
