International Space Station Makes 100,000th Orbit

May 17, 2016 – The International Space Station (ISS) made its 100,000th orbit of Earth on Monday, May 16. The station travels at a speed of 17,500 miles per hour (five miles per second), orbiting Earth every 90 minutes. From the time the first component of the station was launched, the station had traveled about 2,643,342,240 miles, or roughly the distance between Earth and Neptune.

Orbital assembly of the space station started with the launch from Kazakhstan on November 20, 1998 of the first bus-sized component, Zarya. A few weeks later, the U.S. space shuttle carried the Unity connector module into space. Constructed on opposite sides of Earth, Unity and Zarya were joined in space to begin the orbital station’s assembly and an unprecedented multinational partnership.

The ISS has been the most politically complex space exploration program ever undertaken, bringing together international flight crews, multiple launch vehicles, globally distributed launch, operations, training, engineering, and development facilities; communications networks, and the international scientific research community.

An international crew of six people live and work on the station, which has been continuously occupied since November 2000. In that time, 222 people from 18 countries have visited the station. Crew members spend about 35 hours each week conducting research that advances scientific knowledge in Earth, space, physical, and biological sciences for the benefit of people living on our home planet.

The space station has grown and evolved into an unprecedented, state-of-the-art laboratory complex. Offering a microgravity environment that can’t be duplicated on Earth, the ISS continues to further humankind’s knowledge of science and how the human body functions for extended periods of time in space — all of which will prove to be vital on long-duration missions beyond low-Earth orbit, including to Mars.

More than an acre of solar arrays provide power to the station, and also make it the brightest object in the night sky after the moon. You don’t need a telescope to see it and you can sign up for text messaging or email alerts to let you know when (and where) to spot the station as it flies over your town.