Spaceflight
What Is the International Space Station?
For more than two decades, humans have lived without a break aboard a laboratory the size of a football field, circling the planet every 90 minutes. Here is what the International Space Station is and why it exists.
How Do Satellites Stay in Orbit Without Falling?
Thousands of satellites circle overhead right now, and gravity is pulling on every one of them. So why don’t they fall? The answer is stranger and simpler than it sounds.
How Do Rockets Actually Reach Orbit?
Getting a rocket up to space is the easy part. The real trick, and the reason rockets are almost all fuel, is going sideways fast enough to fall around the planet forever.