Earlier Wednesday, the pump module on one of the space station’s two external cooling loops automatically shut down when it reached pre-set temperature limits. These loops circulate ammonia outside the station to keep both internal and external equipment cool. The flight control teams worked to get the cooling loop back up and running, and they suspect a flow control valve actually inside the pump itself might not be functioning correctly.
At no time was the crew or the station itself in any danger, but the ground teams did work to move certain electrical systems over to the second loop. Some non-critical systems have been powered down inside the Harmony node, the Kibo laboratory and the Columbus laboratory while the teams work to figure out what caused the valve to not function correctly and how to fix it. The crew is safe and preparing to begin a normal sleep shift while experts on the ground collect more data and consider what troubleshooting activities may be necessary.
The six-person Expedition 38 crew of the International Space Station spent Wednesday preparing their orbital home for some future upgrades as well as training for the upcoming robotic capture of a commercial cargo craft.
Flight Engineers Rick Mastracchio and Koichi Wakata worked for much of the morning inside the Quest airlock, reconfiguring it for a new Nitrogen Oxygen Recharge System, or NORS. Nitrogen and oxygen are needed for replenishment of the station’s cabin breathing air as well as for operation of the Quest airlock and the station’s pressurized ammonia cooling system. The NORS recharge tank, which can be sent to the station aboard a resupply vehicle, provides a new way of supplying the complex with those gases. Mastracchio and Wakata reorganized spacewalk equipment and systems inside Quest to prepare it for NORS.
Later Mastracchio and Wakata joined Flight Engineer Mike Hopkins for another round of on-board training to review procedures for the robotic capture and berthing of Orbital Sciences’ Cygnus commercial cargo craft, which is scheduled to launch Dec. 18 from Wallops Flight Facility in Virginia. When Cygnus approaches the station on Dec. 21, the astronauts will use the station’s 57-foot Canadarm2 robotic arm to reach out and grapple the vehicle for its installation to the Earth-facing port of the Harmony node. This flight, designated Orbital 1, will be the first commercial resupply mission to the station by Orbital Sciences.
[image-93]Hopkins also conducted a checkout of the display and control panels for the robotic workstations inside both the cupola and the Destiny laboratory, making sure the critical functions of these systems are ready to support the capture of Cygnus.
Cygnus is bringing up a number of experiments to the station, including test sample materials for the second iteration of a study known as Burning and Suppression of Solids, or BASS-2. By taking a detailed look at how the combustion of solid materials differs in a weightless environment, researchers are able to select safer materials for space hardware and improve strategies for putting out accidental fires aboard spacecraft. The research also provides scientists with improved computational models that will aid in the design of fire detection and suppression systems here on Earth.
Hopkins rounded out his day inside the Tranquility node conducting an inspection the Combined Operational Load Bearing External Resistance Treadmill, or COLBERT, to identify any damage to the teeth of its tread belt.
[image-94]Flight Engineers Mikhail Tyurin and Sergey Ryazanskiy meanwhile checked out the treadmill in the Russian segment of the station. The two cosmonauts temporarily removed the treadmill’s vibration isolation system to measure the amount of force being applied to the exercise device’s torsion bar during exercise.
Ryazanskiy also continued the replacement of fans in the Zvezda service module with low-noise units and used a sound level meter to measure the results.
Tyurin participated in the Interactions experiment, which studies the impacts of personal, cultural and national differences among crew members.
Commander Oleg Kotov spent part of his day updating software for the Napor-mini RSA experiment, which utilizes an optical telescope and a small radar system for monitoring Earth’s environment
The commander later performed routine maintenance on the Elektron oxygen generator.