Russian cosmonauts Alexander Skvortsov and Oleg Artemyev on Monday ventured outside the International Space Station (ISS) to conduct a planned six-hour and 15-minute spacewalk focused on scientific experiments and routine maintenance work, Russia's Federal Space Agency Roscosmos told RIA Novosti.

The first task performed by the cosmonauts was the launch of the NS-1 nanosatellite, a spokesperson for the Russian mission control center said.

The 1.5-kg satellite, unofficially dubbed as the Peruvian CubeSat Chasqui-1, will transmit camera images and telemetry back to Earth for further academic studies by students under the Radioscaf educational program.

As part of the spacewalk, Skvortsov and Artemyev mounted the Expose-R experiment package on the station's hull. The experiment serves to research the long-term influence of the space environment on the survival of bacteria, fungi, plants and animals.

Russian astronauts will also photograph the thermal shield of the outer surface of the Russian segment of the ISS. The final task of the astronauts will be to isolate and retrieve a Biorisk experiment container, which analyzes how microbial growth affects materials in space.

According to NASA, this is the 181st spacewalk devoted to ISS assembly and maintenance since construction of the space outpost began in 1998, the fourth so far this year and the second for both Skvortsov and Artemyev.