# How does the ISS maintain orbit across a range of altitudes?

I am a physics student preparing a presentation on the ISS, one of my
topics will cover orbital information. My question is that for a stable
orbit to be maintained a satellite must maintain a fixed relationship
between altitude and velocity, otherwise due to atmospheric drag it
will decrease in velocity and be overcome by the earth's
gravitational field and begin re-entry. After examining the altitude
information on the ISS released by NASA, I have seen that the ISS
operates over a wide range of altitudes, and as it slowly decreases in
height it re-boosts back up to maintain its height, from what I have
been taught so far for a satellite to maintain stable orbit it must
conform to V = SquareRoot GM/R, if for example the satellite falls
10km, does it therefore increase it's speed in order to stop it losing
more altitude, and when re-boosted does it decrease its speed in order
to stop it exiting orbit? Or can it operate comfortably across a range
of altitudes without significant effect? Anyone who can shed light on
this for me your help is much appreciated, thanks.

Jarrod.

.

## Relevant Pages

• Re: How does the ISS maintain orbit across a range of altitudes?
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• Re: Are politicians averse to leaving LEO?
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