How Long Does the ISS Take to Orbit Earth? About 90 Minutes
How long does the ISS take to orbit Earth? About 90 to 92 minutes, so its crew sees 16 sunrises a day. Learn why, how fast it goes and how high.
The 30-second summary
- The ISS circles Earth once every 90 to 92 minutes, which adds up to 16 orbits a day.
- So its crew sees 16 sunrises and 16 sunsets every 24 hours, as the station races at 28,800 km/h about 400 km up.
- The figures are approximate and vary a little by source and date: NASA rounds to 90 minutes, while ESA says 92.
How long does the ISS take to orbit Earth? About 90 to 92 minutes. In 24 hours it makes 16 orbits, so, according to NASA, its crew passes through 16 sunrises and 16 sunsets every day.
Below you'll find why the station never crashes even though it is always falling, how fast and how high it flies, and how scientists know these numbers.
How does it work?
It sounds strange, but the station is falling toward Earth all the time. NASA describes an orbit as a constant tug-of-war between an object's tendency to keep moving in a straight line and gravity pulling it back. When the two are balanced, the object keeps falling toward the planet, but it moves sideways fast enough that it never hits it. That is why the station's huge speed is what keeps it up there.
The ISS is in what's called low Earth orbit. According to the European Space Agency (ESA), it flies about 400 km high at 28,800 km/h, roughly 8 km every second. At that speed, a full lap around Earth takes 92 minutes; NASA rounds it to about 90.
On every lap, the station passes from Earth's sunlit side to its dark side and back again. So the crew gets a sunrise and a sunset with each orbit: 16 of each every 24 hours.
How do we know?
The orbit figures come from the space agencies that run the station. NASA's facts page (updated 2024) says the ISS orbits Earth about every 90 minutes at five miles per second and makes 16 orbits in 24 hours. ESA gives an altitude of 400 km, a speed of 28,800 km/h and a full circuit in 92 minutes.
There is photo evidence too. On April 12, 2010, astronauts took a time-lapse series of photographs from the station, later published by NASA's Earth Observatory. It starts with sunrise over Northern Europe and ends with sunset southeast of Australia, covering only roughly half an orbit. At the time, the station was 354 km up and completed an orbit every 92 minutes.
And also
According to NASA, the station travels the equivalent of a trip to the Moon and back in about a day. And because Earth turns underneath it, each orbit shifts about 2,200 km to the west, so it passes over different places.
But keep in mind
- "90 minutes" is NASA's rounded figure; ESA and NASA's Earth Observatory give 92 minutes. That's why we say 90 to 92.
- Altitude and speed differ between sources depending on when they were measured: in 2010 the Earth Observatory gave 354 km and 27,700 km/h, while ESA gives 400 km and 28,800 km/h.
- The sunrise count is approximate too: NASA says 16 in 24 hours, while the Earth Observatory said in 2010 that it is 15 or 16 a day.
- "To the Moon and back in about a day" is NASA's rough comparison to help picture the distance, not a precise measurement.
FAQ
How many times does the ISS orbit Earth in a day?
According to NASA, 16 times in 24 hours, since each orbit takes about 90 to 92 minutes. That's why the crew sees 16 sunrises and 16 sunsets a day.
How fast does the ISS orbit the Earth?
ESA puts its speed at 28,800 km/h, which is roughly 8 km every second. NASA describes it as five miles per second.
How far is the ISS from Earth?
About 400 km, according to ESA. In 2010 NASA's Earth Observatory gave 354 km, so the figure depends on when it was measured.
Can you see the ISS from the ground?
Yes. ESA says you can see the station with your own eyes if you look up at the right time.
Sources
- 1
- 2Where is the International Space Station?ESA (European Space Agency)
- 3What Is an Orbit? (Grades 5-8)NASA · 2025
- 4Sunrise to Sunset aboard the Space StationNASA Earth Observatory · 2010
These are the original sources; we only explain them. Read them yourself.
Want the source?
Comment this word under any of our Instagram posts and we’ll DM you the link to the source.
Instagram postWas this article useful?
