Two Russian astronauts began a six-hour spacewalk Thursday, February 16 to work on the International Space Station's (ISS) meteorite shields and perform experiments, according to the Interfax news agency.

Cosmonauts Oleg Kononenko and Anton Shaplerov were scheduled to install new shielding to protect the station's work module from microscopic rock particles and space junk, officials at Russia's national space agency Roscosmos said.

The astronauts would also take samples from several sections of the station's exterior surface as part of ongoing research on the long-term effect of cosmic particles on a spaceship.

They also planned to transfer one of the station's robot arms to a new work site, and carry out station maintenance.

The ISS' shields and solar arrays are under constant bombardment by microscopic space particles. Astronauts sometimes use the station's rockets to shift its position, to avoid larger objects.

Six astronauts are currently aboard the ISS: Shkaplerov, Kononenko, fellow Russian Anatoly Ivanishin, the US' Daniel Burbank and Donald Petit, and Andre Kuipers from Netherlands, M&C reported citing DPA.