It is definitely not the International Space Station which orbits the earth at an altitude of 249 miles and is visible for a maximum of 6 minutes moving rapidly across the sky. Communication satellites do maintain a stationary position about 24,000 miles above the equator, but I would be surprised if one were large enough to be seen by the naked eye. My guess is that it is either a NASA or European Space Agency radio telescope used to collect data from deep space.