ESA Blog: 20 questions for 20 years: Happy Birthday International Space Station. “This week we celebrate 20 years since the first International Space Station module Zarya was launched into space on 20 November, 1998. To mark the occasion, we are answering 20 of your most frequently asked questions about Alexander Gerst’s time on board the orbital outpost. Read on to be enlightened…”
“Is there gravity in space?
In truth, astronauts are not floating, they’re ‘falling’. But because of the high speed of the Space Station’s orbit, they fall ‘around’ Earth – matching the way Earth’s surface curves. The moon stays in orbit around Earth for this same reason. Since astronauts have the same acceleration as the Space Station, they appear and feel weightless.”