Exiting the Airlock
Exiting the Airlock Expedition 35 astronauts Chris Cassidy and Tom Marshburn climb outside the International Space Station to begin work on an ammonia leak. The pair successfully replaced a pump controller box on the station's far port truss (P6) which addressed the leak. NASA / Chris Hadfield

"We're changing the world. Are you in?"
- CEO Bill Nye

Sign up for email updates