Washington, Dec 10 (IANS): Two Russian cosmonauts will go for a six-hour-long spacewalk on Tuesday to check a hole in the external hull of the Soyuz MS-09 spacecraft currently docked to the International Space Station (ISS).

Oleg Kononenko and Sergey Prokopyev of Russian space agency Roscosmos are scheduled to begin their spacewalk at 11 am EST, NASA said.

While this will be the fourth spacewalk in Kononenko's career, Prokopyev will be out on his second.

In late August, a pressure leak occurred on the space station that was traced to the Soyuz.

Within hours after finding the source of the leak, the Expedition 56 crew sealed the hole and the station has since maintained a steady pressure.

Now the cosmonauts will take samples of any residue found on the hull and take digital images of the area before placing a new thermal blanket over it.

The samples and images will provide additional information that will aid the investigation into the cause of the pressure leak, NASA said.

The spacewalk was initially planned for November 15 and Prokopyev was set to perform it alongside Russian cosmonaut Alexey Ovchinin, Sputnik news agency reported.

However, the latter did not make it to the ISS due to a failure of the Soyuz-FG booster carrying the Soyuz MS-10 spacecraft with Ovchinin and NASA astronaut Nick Hague on board in October, the report added.

The spacecraft that Kononenko and Prokopyev will check on Tuesday are scheduled to return Prokopyev, NASA astronaut Serena Aunon-Chancellor, and ESA (European Space Agency) astronaut Alexander Gerst from the space station to Earth on December 19 (US time).

The three will return home after a six-and-half-month mission.