Science Focus - the home of BBC Science Focus Magazine
What altitude must satellites reach to stay permanently in orbit? © Getty Images

What altitude must satellites reach to stay permanently in orbit?

Subscribe to BBC Science Focus Magazine and get 6 issues for just £9.99

Getting a satellite into orbit is hard enough, and staying in orbit means avoiding atmospheric drag.

Asked by: Ludo Webb, Manorhamilton

Advertisement

Getting satellites into orbit is hard enough - they need to be hurled into space with enough energy to reach around 26,000km/h. But staying in orbit means avoiding losing energy to the Earth's atmospheric drag. While the official threshold of space is 100km above the Earth, the effects of the atmosphere can be detected much higher.

Even Hubble, which orbits at almost 600km, could be brought down by the creeping effect of drag. Only satellites in orbits several tens of thousands of kilometres above the Earth can be regarded as effectively permanent, though even they are not totally immune to atmospheric drag.

Read more:

Advertisement

Authors

Robert is a science writer and visiting professor of science at Aston University.

Advertisement
Advertisement
Advertisement

Sponsored content