Two Russian cosmonauts started their working week at the International Space Station on Monday by venturing out of the orbiting lab for tasks that include cleaning the windows.

Gennady Padalka, who serves as the station' commander, and flight engineer Mikhail Kornienko also added new equipment outside of the station and took pictures to study the lab's exterior during their five and a half hour spacewalk.

The pair finished their spacewalk 40 minutes ahead of schedule after they breezed through their first task of installing gap spanners on the station's hull that would help station crew member maneuver outside of the orbiting lab, which floats 250 miles above the Earth's surface.

Padalka and Kornienko began their spacewalk at 10:20 a.m. EDT and this ended at  3:51 p.m. EDT after the pair culminated their tasks and eventually closed the hatch of the Pirs module.

The two cleaned the windows to remove the dirt left by the exhaust fumes from visiting vehicles, replaced an old antenna, took photos of locations and hardware on Zvezda command module and installed fasteners on communication antennas.

"They developed a (cleaning) tool kit with two swabs with handles on them. The swabs are kind of a type of terry cloth," said spacewalk specialist Devan Bolch. "It's kind of similar to what you would use on your car headlights, when they get hazy, to clean them."

The astronauts took footage of their outing using small hand-held cameras while they were in constant communication with each other and the mission control in Russia.

The expedition marks the fourth spacewalk at the ISS this year. It is also the 10th for Padalka, who currently holds the record as the most experienced space flier in the world. He had three stays aboard the orbiting station totaling 845 days as of Monday. The expedition outside the station is the second time for Kornienko.

While the two cosmonauts ventured outside of the station, other crew members harvested and ate a few leaves of red romaine lettuce that was grown in space, a culinary first for the station. It was the first time that the astronauts ate their own produce.

"The space station is a lot of white and aluminum and it's kind of a sterile environment," said Expedition 44 flight engineer Kjell Lindgren. "It's really fun to see green, growing things in here that we're intentionally growing for sustenance. And so we sure appreciate this payload and the opportunity to grow and eat and harvest these crops."