A view from inside the station can look almost still. Outside, Earth is passing beneath a laboratory that completes about sixteen orbits each day. Speed is easier to understand when you can move through one of those orbits yourself.
The diagram is a simplified 90-minute orbit, not the station's live position. Use the live map linked below to see where the ISS is now.
Try one orbit
A sideways fall.
Move through a simplified 90-minute circuit. The station and Earth are not to scale; this is not the current ISS position.
The inward line represents gravity's direction. Only your input moves the diagram.
It is falling, but missing the ground
Gravity still acts strongly at the station's altitude. The ISS is not beyond gravity, and its engines do not have to hold it up like a hovering helicopter.
Instead, the station has enough sideways speed that as gravity curves its path downwards, the surface of Earth curves away beneath it. This is continuous free fall around the planet. Our circular diagram illustrates that idea; the real orbit is not a perfectly fixed circle.
Sources: NASA Glenn, What is microgravity?
The crew and the station fall together
An astronaut, a loose object and the station share nearly the same falling motion. The floor no longer needs to push upwards on the astronaut as a floor on Earth does. That is why objects appear to float inside.
Microgravity is a better description than the absence of gravity. Small disturbances remain, but gravity is also the reason the station stays on its orbital path.
Sources: NASA Glenn, What is microgravity?
Read an approximate speed as an approximate speed
The rounded figure of about 28,000 km/h describes the scale of the motion. A current calculated reading can differ because it describes a particular position, time and model. It is not a contradiction when a live display has more digits than a rounded educational figure.
On our Now page, the position is calculated from stored orbital elements. The update stamp shows when we last checked the source successfully, not the age of the underlying orbital elements. A moving marker is a calculation, not a video feed or a direct measurement received every second.
Sources: NASA, Spot the Station frequently asked questions · Space Right Now, the ISS position and source timestamp
Overhead does not always mean visible
The station is visible because it reflects sunlight. A useful sighting needs the station to be lit and the observer's sky dark enough, so opportunities often occur around dawn or dusk. A ground track alone is not a prediction that you can see it.
NASA's Spot the Station service provides local viewing opportunities. Our current map is useful for following the orbit; it does not yet promise a visible pass from your location.
Sources and method
Checked 11 October 2026. Explanations are written by Space Right Now with AI, from the sources below. The organisations cited have not reviewed or endorsed this page and are not responsible for the accuracy of this AI-written explanation.
- NASA, Spot the Station frequently asked questions
NASA-owned factual and explanatory text. No partner imagery or author portrait is reproduced. Checked 11 October 2026.
- NASA Glenn, What is microgravity?
NASA-owned educational text. The diagram on this page is our own labelled schematic. Checked 11 October 2026.
- Space Right Now, the ISS position and source timestamp
Description of our own CelesTrak-based position calculation and visible freshness state, not a third-party article. Checked 11 October 2026.