They are part of missions supervised by the Johnson Space Center called the ISS Crew Earth Observations experiment and Image Science & Analysis Laboratory.
When not involved in other duties, astronauts spend time capturing images of the Earth, celestial objects and visiting space vehicles they believe could be useful to those on the ground and elsewhere on the ISS.
Many of the images can be viewed at the Gateway to Astronaut Photography of Earth.
The image to the right shows the new observation platform that makes the capturing of such important images possible.
Cupola was built by the European Space Agency and contains seven windows used to conduct experiments. The dome is the largest window ever used in space.
Before Cupola was added earlier this year, astronauts had been confined to looking through small portholes to see anything outside of their orbiting home.
All of Cupola’s windows are equipped with shutters to protect them from damage by micrometeorites and orbital debris.
The module's addition means that the original design of the ISS is nearly complete.
Full story and image: NASA