Russian cosmonauts Oleg Kotov and Sergei Ryazanskyi ventured outside the International Space Station (ISS) on Monday to install two commercial Earth-observing cameras on the exterior of the Russian Zvezda service module. The cosmonaut duo enjoyed varying levels of success, with one camera still suffering from telemetry issues.
EVA-37A Objectives – REFER TO LIVE UPDATES
The main objective of the EVA, designated EVA-37a, was to install a high resolution camera and a medium resolution camera on a biaxial pointing platform on the Zvezda service module.
The two cameras are part of a joint project of the Russian space agency and a Canadian company, which aims to provide high resolution views of the Earth to internet subscribers.
Both cameras were providing good telemetry data to controllers at Mission Control in Moscow, prior to the MRC becoming problematic later in the EVA.
Other objectives for the EVA included the retrieval of a material science experiment container mounted on the Pirs module and the removal of a loose pin on external hardware.
The previous EVA, conducted on December 27, shared most of its objectives with EVA-37a.
Kotov and Ryazanskyi first installed a foot restraint to help them stabilize themselves at the biaxial pointing platform.
Then, they installed and connected the high resolution camera, which was followed by installation of the medium resolution camera.
After the cosmonauts finished routing power and data cables along Zvezda’s hull and connecting the cables to the camera platform, controllers in the MCC in Moscow (MCC-M) proceeded with activation of the two cameras.
However, they discovered they were unable to receive telemetry from the cameras. Without telemetry, the controllers had no way of telling if the cameras were receiving power.
As discussions and attempts to activate the cameras went on in MCC-M, the spacewalkers continued with the planned tasks of the EVA. Finally, MCC-M controllers, along with the camera engineers, decided to uninstall the cameras and bring them inside the ISS for troubleshooting.
The rationale for returning the cameras inside the ISS related to the fact that the camera’s internal heaters would not function without power, exposing the cameras to the extreme temperature differences of the day and night side of the station’s orbit.
This led to deferring the remaining tasks to a later EVA, so that the cosmonauts had enough time and consumables to bring the cameras back inside.
Even with some of the tasks replanned for EVA-37a, EVA-37 still broke the Russian record of the longest spacewalk, with its eight hours and seven minutes duration.
In the weeks following the EVA, RSC Energia and MCC-M – with the help of the Russian crew – conducted troubleshooting of the problem, which was eventually attributed to a cabling issue inside the ISS.
“On January 2nd, the crew found a badly docked cable connector inside the Zvezda module,” noted source information in L2’s RS-37 section. The source information also noted that the only way to verify that the issue is resolved is to connect the cameras on the outside.
The EVA crew egressed the Pirs airlock at 8:00 central time. They first retrieved the two cameras from the airlock and took them with them to the Zvezda service module.
On the service module’s plane IV is a universal work platform, called URM-D, on which the biaxial pointing platform (DPN) is installed.
The crew re-installed the high resolution camera on the DPN, and the medium resolution camera on the URM-D base. Both cameras were classed as in good health and providing telemetry to the ground. However, the MRC then began to suffer from some connection issues.
Following some work with the connections, Russian controllers opted not to conduct any additional actions on the camera during this EVA. Troubleshooting will continue via ground teams, with the spacewalkers told another EVA won’t be required.
The Russian duo also worked through the tasks that were deferred from EVA-37.
This included the removal of a cassette container (SKK2-SO) which exposes different material samples to the space environment, from the Pirs module, returning it back inside.
After these primary objectives were completed, the crew conducted a photo survey of the exterior of the Russian segment, prior to the conclusion of the EVA after six hours and eight minutes.
This was Kotov’s 6th and Ryazanskyi’s 3rd EVA, the third for the pair during Expedition 37 and 38. Both were wearing Russian Orlan suits, with Wireless Video System cameras borrowed from the US segment installed on their helmets.
The rest of the Expedition 38 crew remained inside the ISS, but are separated, as the transfer compartment between Zvezda and Zarya had to be sealed in case the spacewalking crew ran into problems with the Pirs airlock – an issue that could have potentially resulted in them having to use the backup airlock – Poisk.
Mike Hopkins who arrived on Soyuz 36 with the spacewalkers, was isolated in the Soyuz for the duration of the EVA.
The rest of the crew – Rick Mastracchio, Koichi Wakata, and Mikhail Tyurin, were free to move around the US segment and the Zarya and Rassvet modules, with their work including manifest checks for the upcoming arrival of SpaceX’s Dragon spacecraft on its CRS-3/SpX-3 mission, now set to launch no sooner than March 1.
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(Images: via L2’s ISS and Russian Sections – Containing presentations, videos, images and ongoing ISS status updates, with additional images NASA and CSA).
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