Russian astronauts launch microsatellite
Cosmonauts Gennady Padalka and Yuri Malenchenko, working in open space, have successfully launched the microsatellite Sphere.
During their spacewalk, Padalka and Malenchenko are also installing additional anti-meteor panels on the International Space Station.
The two cosmonauts are also retrieving from the outside surface of the ISS samples of materials that were there for a length of time to study the effects of cosmic radiation.
If the astronauts have time, they will perform a succession of other tasks.
The Russians ventured into raw space at 19:37 (GMT), and are scheduled to work in open space for about 6.5 hours.