How close to Earth do satellites orbit?
Satellites in low Earth orbit are at least 130 kilometers (81 miles) above Earth’s surface. Lower than this, the satellite experiences too much air resistance and falls back to Earth immediately. A satellite in low Earth orbit completes a revolution in about 1.5 hours travelling about 17,000 kilometers per hour. The International Space Station is in low Earth orbit and the Space Shuttles are limited to low Earth orbit (despite movie depictions to the contrary). Satellites in low Earth orbit are easiest to see because they move rapidly against the background stars. Satellites in higher orbits travel slower, so they take longer to complete one revolution. A satellite that takes 24 hours to orbit Earth is in a geosynchronous orbit. That is, the satellite goes around Earth as rapidly as Earth rotates, so the satellite appears to stay above a region on Earth’s surface. Most communications and weather satellites are in geosynchronous orbits so they can communicate with or observe a particula
