Cosmonauts Sergey Prokopyev and Dmitry Petelin

MOSCOW – Cosmonauts Sergey Prokopyev and Dmitry Petelin have halted preparations for their spacewalk over the malfunction of pumps in the cooling system of one of the spacesuits, Roscosmos said on Friday.

"An abnormal operation of pumps in the cooling system of one of the spacesuits has been found in the process of preparing the spacesuits for the extravehicular activity. A decision has been made to stop the preparations for the exit. The causes are being analyzed," Roscosmos said in a statement.

The spacewalk was expected to begin at 2:20 p.m. Moscow time.

The extravehicular activity scheduled for November 25 was set to become the fourth spacewalk in Prokopyev’s career and the second for Petelin.

During their spacewalk, the cosmonauts were expected to move a heat exchanger from the Rassvet mini-research module to the Nauka multipurpose lab on the orbital outpost’s Russian segment with the help of the ERA robotic arm.

The heat exchanger is needed to remove extra thermal loads from the Nauka multipurpose laboratory module during scientific experiments.

The date of the next spacewalk will be specified after the causes of the canceled extravehicular activity are analyzed, Roscosmos said.

The canceled spacewalk was expected to last about six hours and 37 minutes, with Prokopyev wearing Orlan-ISS spacesuit No. 5 with red stripes and Petelin working in Orlan-ISS spacesuit No. 4 with blue stripes. (TASS)