New European Robotic Arm starring in the next spacewalks

On board the ISS, preparations are underway for two new spacewalks operated by Roskosmos. The events will be in live at NASA TV.

Cosmonauts Sergey Prokopyev and Dmitri Petelin will venture out of the Poisk module on next Wednesday, May 3 and Friday, May 12, 2023  to transfer an experimental airlock to the Nauka module to relocate a cooling device. Last April 19, the cosmonauts completed the first of three steps to transfer the device from Rassvet to the Nauka module.

The Rassvet module’s airlock and the radiator were installed during Shuttle Atlantis’ STS-132 mission in May 2010 and will be transferred via ESA’s robotic arm from Rassvet to the Nauka module driven by cosmonaut Andrey Fedyaev, operating inside the station.

The previous steps

The next two EVAs are not the first of this mission. Since last year, procedures have been carried out for this transfer to support the Nauka Module and it has not been without its drawbacks. Prokopyev and Petelin exited the station’s Poisk module as early as April 19, repeating many of the same preparatory steps they did in two previous attempts to perform the same set of tasks.

On their first attempt, on November 25, 2022, Roskosmos air traffic controllers had to interrupt the spacewalk due to a problem that appeared at the pump of Prokopyev’s Orlan spacesuit, before the two cosmonauts had entered the airlock.

Then, on December 14, while the cosmonauts themselves were waiting for the airlock to completely depressurize, a probable micrometeorite hit the Russian Soyuz MS-22 spacecraft which, hit at a sensitive point, lost its coolant in space. Although cosmonauts were never in danger, it was necessary to take stock of the damage situation and once again the EVA was postponed.

On April 19, Prokopyev and Petelin finally completed the spacewalk, continuing the work of the previous excursion made on November 17, 2022. The cosmonauts manually freed the locks that held the radiator to the module, and transferred it to be operative for Nauka.

With the support of ESA’s new European Robotic Arm (ERA), operated by flight engineer and cosmonaut Andrey Fedyaev, from the control panel inside ISS, the transfer of 570 kg (1,256 lbs) device was completed.

It was the first major practical task performed by the arm.

The Airlock

The ShK is a cylindrical airlock compartment that serves as a vestibule for equipment heading towards the vacuum of space and back into the pressurized interior of the station. It can be used for fully robotic operations and to support spacewalks. Outside the airlock is equipped with all the necessary railings and a footrest to help cosmonauts in spacewalk. It also has a gripping device for a robotic arm, FRGF, and a passive accessory, called UFP4, for potential payloads. 

The SSA-M coupling system is designed to connect the airlock to the pressurized adapter, on the Nauka module. The Nauka has the active part of the mechanism, known as ASA-M (Agregat Stykovochny Aktivny – Modifitsirovanny) and the airlock itself is equipped with its passive counterpart, ASP-M. 

Inside, it can carry up to 150 kg of payload. The equipment is connected to a special mobile tray, which can slip out of the airlock after its depressurization and opening of its outer cover, all under remote control. The tray also has a “base point” for the robotic arm, which can grab it and move the package to a different location outside the station if necessary.

The mission crew

Sergey Prokopiev is a flight engineer and currently ISS commander of the Expedition 68.

Dmitriy Aleksandrovich Petelin, Soyuz MS-22 crew member with Prokopyev,  specialist as pilot and helicopter pilot, he is on his first mission in space.

Andreiy Fedayev is a cosmonaut first space mission and pilot engineer. He joined the “seat swap” program, as a crew member of the Soyuz MS-23 and he was reassigned to SpaceX Crew 6 flight. He led the European Robotic Arm in this mission.