Astronauts have been working hard on their third and final spacewalk of a mission to add windows to the International Space Station.
The Italian-built dome has seven windows providing spectacular views of earth 220 miles below. The extension has cost $27m making it by far the most expensive piece of glass ever fabricated.
The Tranquility Node was initially installed on Friday, with electrical connections and cooling systems being added in a series of spacewalks over the weekend.
US astronaut Bob Behnken and British-born colleague Nicholas Patrick finished the job by removing insulation covers from the observation dome's windows.