A prematurely-ended Russian spacewalk took place at the ISS Wednesday to continue preparations to fully activate the European Robotic Arm (ERA) and commission it for operational use.
The ERA, which launched to the station last year, will be used – among other things – to transfer a scientific airlock and radiator to the Nauka module.
The spacewalk, known as RS EVA-54, began with hatch opening on the Poisk module at 13:53 UTC on Wednesday, August 17, 2022, and was expected to last approximately six hours 45 minutes. However, two hours 17 minutes into the spacewalk, Artemyev observed a drop in battery voltage in his Orlan spacesuit and was ordered back to the airlock immediately.
After an hour of troubleshooting, Russian control teams determined that the EVA could not continue. The ERA was re-stowed, and Matveev joined Artemyev in the airlock.
Poisk’s hatch was closed at 17:54 UTC, bringing an end to the spacewalk.
Russian cosmonauts Oleg Artemyev and Denis Matveev were the two station crewmembers performing the EVA, which was the 63rd Russian spacewalk in support of the construction and maintenance of the International Space Station.
It also marked the sixth of 10 planned Nauka/ERA outfitting EVAs that have been in work since the module arrived at the station in July 2021.
Overall, since March 1965, 72 cosmonauts have conducted 158 spacewalks. Today’s EVA was the 159th, though it did not add to the total number of spacewalking cosmonauts as this was Artemyev’s seventh spacewalk and Matveev’s third.
For RS EVA-54, Artemyev and Matveev both wore Russian Orlan spacesuits. Artemyev wore the suit with the red stripes while Matveev wore the suit with the blue stripes.
The main aim of the spacewalk was to test and commission the ERA for future operational use.
Upon egressing the Poisk airlock, the first task for the duo performed was translation to the Nauka module, whereupon they installed a Camera Light Unit (CLU) on one of ERA’s two booms.
A launch restraint ring was also removed from the ERA’s End Effector 2, based on the BTL3 base point. The End Effectors of robotic arms are essentially the system’s “hands,” allowing the arms to grab tools, spacecraft, equipment, and power/data grapple fixtures outside the station.
The duo then started installation of another CLU on the ERA’s second boom section, but this is when the EVA was interrupted by Artemyev’s suit battery voltage drop issue.
The next task for Artemyev and Matveev was to have been a translation to the External Man Machine Interface (EMMI) control panel located on the side of the Nauka module.
The EMMI allows spacewalkers to manually control the ERA directly whilst on spacewalks.
The EMMI would have been disconnected from its current location and relocated to the front of the Nauka module, whereupon it would have been installed on a handrail and connected to the BTL3 base point via a single cable.
The ERA would then have been maneuvered via Intra Vehicular (IV) control by cosmonaut Sergey Korsakov to the BTL2 base point.
Here, the spacewalkers would have taken control of the ERA via EMMI and conduct test maneuvers. The ERA would then have been commanded to grapple the BTL2 base point.
The spacewalkers would then have proceeded to set and check numerous settings on both of the ERA’s End Effectors using a rotating tool, checking feedback indicators and relaying them to ground control in the process.
Finally, a launch restraint ring would have then been removed from End Effector 1 on the BTL2 base point.
If time permitted, the Strela-2 manual telescopic boom, based on the forward end of the Zarya module, would have been extended back towards the Poisk airlock to create a translation pathway between Poisk and Zarya.
This task was deferred from a previous EVA; however, the translation pathway will be needed on future spacewalks to transfer Nauka’s airlock and radiator.
Overall, RS EVA-54 was the 252nd spacewalk in support of the International Space Station, the seventh so far in 2022, and the fifth Russian EVA of the year.
(Lead image: Matveev and Artemyev work outside the Nauka module during an April 18, 2022 EVA. Credit: NASA)