Astronauts' home in the sky passes a big milestone as the space station rockets around the Earth for the 100,000th time.
NASA marks 40th anniversary of the space science outpost Skylab.
From Earth and sun observations to the evaluation of man's ability to live for long durations in space, Skylab paved the way for every mission that followed.
The International Space Station orbits around Earth every 92 minutes, carrying a clutch of astronauts along with it. Without earlier space stations, such as the US' Skylab and Russia's Mir, mankind may not have had a permanent station in space.