The International Space Station is marking 25 years of nonstop human presence in orbit.

(NASA via AP)CAPE CANAVERAL, Fla. – The International Space Station was a cramped, humid, puny three rooms when the first crew moved in. Two days later, they swung open the space station doors, clasping their hands in unity. With its first piece launched in 1998, the International Space Station already has logged 22 years in orbit. Astronauts spend most of their six-month stints these days keeping the space station running and performing science experiments. “If you look at the space station program today, it’s a blueprint on how to do it.