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Answers Your Questions

From: Nicole, of Santa Barbara, Calif.,
To: Tony Ceccacci, flight director for the orbit 2 team


Question: How long does it take for the space station to circle the Earth?

Answer: It takes approximately 92 minutes for the ISS to complete each orbit. This time will vary based on the station's current orbit -- the orbit continually decays at a very small rate. The orbit is boosted periodically to account for this, so the orbit time is not constant.

If you need a more exact time, you can go to the NASA Human Space Flight home page (spaceflight.nasa.gov) and select Realtime Data, then go to Orbital Elements and choose the ISS orbital elements page. This page has data on an orbit-by-orbit basis. For a given orbit look for the "Mean motion", given in revolutions per day (rev/day). To convert the mean motion value into minutes per revolution for that orbit, divide it by 1440 (= 60 minutes/hour x 24 hours/day).

Kevin McCluney
Ascent/Entry Mechanical Systems


View a list of answered questions or ask MCC your own question.

Curator: Kim Dismukes | Responsible NASA Official: John Ira Petty | Updated: 06/16/2002
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