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Astronauts breeze through US EVA-45

Mark Vande Hei works to lubricate the end effector of the robotic Canadarm2 during U.S. EVA-45. Photo Credit: NASA

Mark Vande Hei works to lubricate the end effector of the robotic Canadarm2 during U.S. EVA-45. Photo Credit: NASA

Less than a week after completing one spacewalk, International Space Station (ISS) Expedition 53 astronauts Randy Bresnik and Mark Vande Hei set out on another extravehicular activity (EVA). This excursion, U.S. EVA-45, lasted about 6.5 hours.

At 7:56 a.m. EDT (11:56 GMT) Oct. 10, 2017, the two NASA astronauts switched their spacesuits over to battery power, officially starting U.S. EVA-45. The primary task of the spacewalk was to replace a faulty camera and begin the process of lubricating the new Latching End Effector (LEE) on the robotic Canadarm2. The LEE was attached on the previous spacewalk on October 5.

Randy Bresnik works to replace an external TV camera on the P1 truss segment. Photo Credit: NASA TV

Randy Bresnik works to replace an external TV camera on the P1 truss segment. Photo Credit: NASA TV

Bresnik, also the station’s commander, was the lead spacewalker and wore the spacesuit with the red stripes, while Vande Hei wore the suit with no stripes.

Once outside the Quest airlock, the two took different paths to their ultimate destination at the P1 truss segment. Bresnik first fetched a foot restraint and moved to the Destiny laboratory to attach it to the module and then demate a heater cable from a Pump Flow Control Subassembly. He rotated the device 90 degrees in order to allow for a future ammonia vent and be used as a spare.

Vande Hei, on the other hand, went straight to the P1 truss to begin setting up the work area. He installed a Worksite Interface Socket on the recently installed LEE.

After that work was finished, Vande Hei joined Bresnik to work on the Pump Flow Control Subassembly, located nearby at External Stowage Platform-1, which is attached to Destiny. It took two astronauts to rotate the washing machine-sized device.

With the pump subassembly rotation competed, the two then moved back to the P1 work site. Bresnik took his foot restraint there from Destiny and attached it onto the 60-foot (18-meter) arm’s LEE.

Once Bresnik was secured onto the foot restraint, Canadarm2 was moved – with him on it – to the furthest port side of the P1 truss. There, he and truss-based Vande Hei worked to replace an external TV camera. In order to get to it, however, the duo had to first remove a working high-definition camera before removing the standard-definition camera for a replacement. Once finished, the HD camera was re-attached.

The astronauts completed this task with breakneck speed, and, at that point, they were about 45 minutes ahead of the spacewalk timeline.

Vande Hei then started to prepare for the other primary task of this spacewalk: lubricating the LEE installed last week. That involved using a Ballscrew Lubrication Tool and a grease gun. The first part greased was the Central Rigidizing Ballscrew in the center of the LEE. Then he moved on to greasing the outer four latch ballscrews.

A diagram of a Latching End Effector for the robotic Canadarm2. Image Credit: NASA

A diagram of a Latching End Effector for the robotic Canadarm2. (Click to enlarge) Image Credit: NASA

The latter part of the grease task was originally planned for U.S. EVA-46 next week. With that assignment now completed, all that needs lubricating on the LEE are the linear bearing tracks and equalization brackets. With arm work for this spacewalk completed, Vande Hei cleaned up his workspace and made his way back to Quest.

Meanwhile, Bresnik worked on some minor tasks. These included removing a Working Interface Socket from the LEE that was removed during last week’s spacewalk. Next, he stowed the foot restraint he was using for this excursion at External Stowage Platform-2 and placed an Orbital Replacement Unit back inside Quest.

Finally, Bresnik began translating to the Tranquility module’s end cone to remove a pair of handrails. This will allow for the installation of advanced wireless antennas in the future for better wireless video transfers from external cameras into the main communications system.

On his way back to Quest to wrap up the spacewalk, Bresnik also removed an insulation blanket from a spare battery charge/discharge unit for eventual use.

Once back inside Quest and the astronauts hooked back up to station power, the spacewalk ended. The 6-hour, 26-minute EVA was officially completed at 2:22 p.m. EDT (18:22 GMT).

This was the second of three planned spacewalks for the month of October. Bresnik, having led the first two, will lead the third. However, while Vande Hei participated in the first two, NASA’s Joe Acaba will venture out with Bresnik on the third, which is currently scheduled for October 18.

The October 18 spacewalk will see the completion of the lubrication of the LEE and replacement of another camera on the Destiny laboratory. Additionally, mission managers are working to add other tasks to the EVA.

U.S. EVA-45 was Bresnik’s fourth spacewalk and the second for Vande Hei. They now have 25 hours, 11 minutes, and 13 hours, 21 minutes of EVA experience, respectively.

Additionally, this was the 204th spacewalk in support of ISS assembly and maintenance since 1998 for a total of 1,272 hours.

Video courtesy of Space Videos



Derek Richardson has a degree in mass media, with an emphasis in contemporary journalism, from Washburn University in Topeka, Kansas. While at Washburn, he was the managing editor of the student run newspaper, the Washburn Review. He also has a website about human spaceflight called Orbital Velocity. You can find him on twitter @TheSpaceWriter.

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