Space Station Reaches Major Milestone — 100,000 Orbits

FILE - Two Russian cosmonauts are seen working outside the International Space Station during a spacewalk in this still image taken from NASA handout video, August 16, 2013.

The International Space Station celebrated a major milestone Monday — 100,000 orbits.

Those orbits around the globe add up to more than 4.6 billion kilometers — or 10 round trips from Earth to Mars, according to NASA.

Since the first module was launched 17 years ago, 222 astronauts and cosmonauts from the U.S., Canada, Russia, Europe and Japan have lived aboard the space station.

Two Americans, three Russians and a British astronaut are currently up there, carrying out a variety of scientific experiments — including tests on mice that experts hope will one day prevent bones and muscles from weakening in space.