Cosmonauts install experiments outside space station

Cosmonauts install the Radiometria experiment today. (NASA)

Two Russian cosmonauts left the International Space Station today to perform several housekeeping chores 222 miles above earth.

Station flight engineers Dmitry Kondratiev and Oleg Skripochka began their six hour orbital walk at 8:30 a.m. EST (1330 GMT), fifteen minutes behind their planned start.

It is the second spacewalk by the cosmonauts within the past month, and the twenty-eighth by Russia in support of the space station.

Twenty-seven minutes into the spacewalk, the duo had installed the Molniya-Gamma experiment on the right side of the Russian Zvezda module.

Molniya "will look at gamma splashes and optical radiation during terrestrial lightning and thunderstorm conditions using three sensors", the Russian Space Agency said on Tuesday.

The cosmonauts then went to work to hook up several electrical connectors between the experiment and the station.

Meanwhile, the station's commander Scott Kelly and cosmonaut Alexander Kaleri worked from the Russian Poisk segment during the spacewalk, while American Catherine Coleman and Italian Paolo Nespoli followed the spacewalk from the Rassevet module which is linked to the Zayra module.

Running ten minutes ahead of schedule, the pair began the installation of a second science experiment just over two hours into the spacewalk.

Installed on the left side of Zvezda, the Radiometria will "collect information useful in seismic forecasts and earthquake predictions," NASA's mission control stated.

The spacewalkers will remove and later bring inside the station "two Komplast panels from the exterior of the Zarya module", NASA's mission control explained today.

"The panels contain materials exposed to space, and are part of a series of international experiments looking for the best materials to use in building long duration spacecraft," the Johnson Space Agency said.

As the spacewalk moved into it's third hour, the launch of a European Space Agency cargo craft moved into it's final hours on earth.

The Johannes Kepler automated transfer vehicle is set to lift-off at 4:55:55 pm EST today, and will dock to the space station eight days later.