Two Russian cosmonauts embarked on a planned five-hour spacewalk at the International Space Station (ISS) on Wednesday to conduct experiments, collect test samples and float a small memorial to the end of World War II in Europe.
Cosmonaut Sergei Volkov released a flash drive containing 70,000 thank-you messages in commemoration of last year's 70th anniversary of Victory Day, celebrating Nazi Germany's surrender in 1945, state news agency TASS reported.
Volkov and fellow cosmonaut Yury Malenchenko, who is set to become the third person to reach 800 consecutive days in space, also collected swab samples from the space station's exterior.
The samples will be used to measure the growth of microorganisms as well as the effects of drastic thermal variations, high radiation and oxidation on the spaceship, which is in orbit about 400 kilometres above Earth.
The cosmonauts also planned to test a material's ability to glue items to the space station, among other experiments.