"In accordance with the ISS flight program, Commander Maxim Suraev and Flight Engineer Alexander Samokutyaev have finished their work in the open space," a Mission Control spokesman said.
The Wednesday spacewalk was supposed to last six hours and was expected to end at 11:37 p.m. Moscow time (19:37 GMT). However, the cosmonauts finished all the planned work, which included removing outdated communications gear and taking pictures of the ISS, early.
This was the second career spacewalk for both Suraev and Samokutyaev, and the 184th overall in support of space station assembly and maintenance.
The ISS operates in low-Earth orbit. It serves as a space environment research laboratory, where crew members conduct experiments in astronomy, meteorology, biology, physics and other fields.
Apart from Samokutyaev and Suraev, the ISS crew currently consists of Americans Reid Wiseman and Barry Wilmore, German Alexander Gerst, and the first-ever femaleastronaut on board the ISS - Russian Elena Serova.