Keep the shuttle flying: Fwd: U.S. astronauts took the first of three spacewalks

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From: "Gary Johnson" <gjohnson144@comcast.net>
Date: February 22, 2015 at 9:17:23 PM CST
To: "Gary Johnson" <gjohnson144@comcast.net>
Subject: FW: U.S. astronauts took the first of three spacewalks

First of Three Spacewalks Complete
February 21, 2015 at 2:39 pm by Mark.

Spacewalkers Barry Wilmore and Terry Virts worked to set up 340 feet of cable on Pressurized Mating Adapter-2 readying it for an International Docking Adapter to accommodate future commercial crew vehicles. Credit: NASA TV
NASA astronauts Barry Wilmore and Terry Virts ended their spacewalk at 2:26 p.m. EST with the repressurization of the Quest airlock. Wilmore and Virts completed all the scheduled tasks for today and one get ahead task. They rigged a series of power and data cables at the forward end of the Harmony module and Pressurized Mating Adapter-2 and routed 340 of 360 feet of cable. The cable routing work is part of a reconfiguration of station systems and modules to accommodate the delivery of new docking adapters that commercial crew vehicles will use later this decade to deliver astronauts to the orbital laboratory.
The 6-hour, 41-minute spacewalk was the first for Virts. Wilmore now has spent 13 hours and 15 minutes in the void of space during two spacewalks. The spacewalk began this morning at 7:45 a.m. Astronauts have now spent a total of 1,159 hours and 8 minutes conducting space station assembly and maintenance during 185 spacewalks.
The duo will venture outside the space station again on Wednesday, Feb. 25, to deploy two more cables and lubricate the end of the space station's robotic arm. NASA TV coverage will begin at 6 a.m. Wednesday ahead of a planned 7:10 a.m. start time for the spacewalk.

U.S. astronauts make renovations to ISS for space taxis
By Amy R. Connolly | Feb. 21, 2015 at 2:15 PM
1 of 2
WASHINGTON, Feb. 21 (UPI) -- Two U.S. astronauts took the first of three spacewalks outside the International Space Station today to create parking spots for so-called space taxis that will ferry crew to and from the station.
Station commander Barry "Butch" Wilmore, 52, and flight engineer Terry Virts, 47, started the spacewalk shortly before 8 a.m. ET for the 6 1/2 hour venture. This is the first of three spacewalks in the next eight days to install wiring for two docking mechanisms for crewed commercial capsules built by Boeing and Space X. It is the first major overhaul of the station since it was completed in 2011.
"We're doing a lot of reconfiguration this year," Kenneth Todd, NASA's International Space Station operations integration manager, said earlier this week. "We are really trying to take the station into this next phase in support of the commercial industries and providers."
The astronauts worked on Saturday to install electrical wiring, new antennas and cables at the station's Harmony module in preparation for the Boeing-built International Docking Adapters. The IDAs will allow the Boeing and Space X spacecraft to dock at the top and front of Harmony beginning in 2017. NASA is hoping to end its dependance on Russia for rides to the ISS since the space shuttle was retired in 2011.
Broadcast live streaming video on Ustream
Wilmore and Virts are expected to continue the work on Wednesday and March 1.
#ISS solar arrays rotate as it orbits Earth to track sun. "Cable Guys" @AstroTerry & #AstroButch still hard at work. pic.twitter.com/qyZUuSTwoY
— Intl. Space Station (@Space_Station) February 21, 2015
@AstroSamantha & me were assist to suit up @AstroTerry & #AstroButch before their more than six-hour spacewalk pic.twitter.com/3mGTbLSSly
— Anton Shkaplerov (@AntonAstrey) February 21, 2015
Hard time connecting cables at home? Try it in a spacesuit w/gloves with Florida & Bahamas ~250 miles beneath you. pic.twitter.com/tNO6HEr4F2
— Intl. Space Station (@Space_Station) February 21, 2015

© 2015 United Press International, Inc. All Rights Reserved.

NASA Astronauts Complete First of Three Planned Spacewalks at ISS
NASA astronauts Barry Wilmore and Terry Virts have successfully finished a spacewalk at the International Space Station (ISS), having performed all the necessary maintenance tasks ahead of schedule.
MOSCOW (Sputnik) – The 6-hour, 41-minute spacewalk took place on Saturday and was the first one for Virts, NASA reported on its website. Virts and Wilmore have two more spacewalks to perform on February 25 and March 1. The astronauts have completed one task ahead of schedule.
The spacewalk series is being conducted primarily to route cables to accommodate the delivery of new docking adapters that commercial crew vehicles will use in the future to bring astronauts to the ISS.
The current ISS crew comprises six specialists from the United States, Russia and the European Union. Wilmore is the mission commander. Flight engineers include Virts, Samantha Cristoforetti from the European Space Agency and three cosmonauts from the Russian Federal Space Agency (Roscosmos) — Elena Serova, Alexander Samokutyaev and Anton Shkaplerov.
Serova became the first female Russian cosmonaut to visit the ISS when its 42nd and current expedition stepped on board the space station on September 26, 2014.

© 2015 Sputnik All rights reserved.

Spacewalkers install cable for new docking adapters
02/21/2015 02:46 PM
By WILLIAM HARWOOD
CBS News

Astronauts Barry "Butch" Wilmore and Terry Virts floated outside the International Space Station Saturday and installed wiring needed for two new docking mechanisms that will be attached later this year for use by new Boeing and SpaceX crew capsules.

The Boeing-built International Docking Adapters, or IDAs, will allow the commercially developed ferry craft to dock at the front and top of the forward Harmony module starting in 2017. Two other ports on the Earth-facing side of the station will be available for use by U.S. cargo ships.

Floating in the station's Quest airlock module, Wilmore and Virts switched their spacesuits to battery power at 7:45 a.m. EST (GMT-5) to officially begin EVA-29, the 185th spacewalk devoted to station assembly and maintenance since construction began in 1998.

This was the first of three spacewalks by Wilmore and Virts to install more than 760 feet of cabling and to attach new antennas to prepare the space station for eventual dockings by commercial crew capsules. The two additional spacewalks are planned for Wednesday and March 1.
Barry "Butch" Wilmore, left, and Terry Virts, right, work on the upper surface of the International Space Station's Harmony module Saturday where new cables are being installed to support new commercial crew docking ports. (Credit: NASA TV)

During Saturday's excursion, the spacewalkers spent most of their time working at the front of the station at the forward end of the Harmony module where a docking port extension known as Pressurized Mating Adapter No. 2 is attached. PMA-2 is where visiting space shuttles once docked and where one of the new IDAs will be attached later this year.

After removing micrometeoroid shields from the forward end cone of Harmony, Wilmore and Virts unplugged no-longer-needed cables and installed new power and data lines to support IDA-1. All in all, Wilmore and Virts deployed about 340 feet of cable.

The astronauts also disconnected four cables from the end cone of the Destiny laboratory module that were once used to deliver power to docked space shuttles. New cables will be plugged in later to support the new docking adapters.

With all of their primary objectives completed, Wilmore and Virts returned to the airlock, ending the spacewalk at 2:26 p.m. for a duration of six hours and 41 minutes.

"Really, really nice work today," astronaut Douglas Wheelock called from mission control in Houston.

This was the second spacewalk for Wilmore and the first for Virts. With the completion of Saturday's work, 120 astronauts and cosmonauts representing nine nations have logged 1,159 hours and eight minutes of spacewalk time, or 48.3 days.

During their second spacewalk Wednesday, the astronauts will unfurl and hook up two more long cables and Virts will lubricate the grapple fixture on the end of the space station's robot arm. During the third outing March 1, they will install new antennas and cabling needed for communications between the station and commercial crew capsules bound for, or departing from, the new docking adapters.

IDA-1 will be launched this summer aboard a SpaceX Dragon cargo ship and robotically attached to PMA-2. IDA-2 will be launched in December. But before it an be attached to the station, the lab crew must robotically move another docking port extension, PMA-3, from an unused port on the Tranquility module to Harmony's upper hatch.

As part of the station's reconfiguration, a cargo storage module currently attached to the Earth-facing port of the central Unity module, will be moved to a port on the forward side of Tranquility, freeing up the Unity port for use by visiting cargo ships. A second cargo port remains available on the Earth-facing side of Harmony.

All told, seven U.S. spacewalks will be needed to complete the station reconfiguration, requiring nearly 650 hours of crew time. Another 230 hours or so will be required for internal wiring changes and robot arm operations.
One of two spacewalking astronauts can be seen floating upside down at the center of this view showing the forward end of the International Space Station. The astronauts installed power and data cables to support new docking mechanisms that will be used by commercial crew capsules starting in 2017. (Credit: NASA TV)

Saturday's spacewalk was originally planned for Friday, but mission managers delayed it one day in the wake of extensive troubleshooting to verify the health of critical spacesuit components known as fan/pump/separators.

The modules in question use a common motor and drive shaft to power three different components: a fan to circulate oxygen, a pump to circulate cooling water and a system to remove, or separate, condensation from the air supply and return it to the cooling water loop.

Failure of a fan/pump/separator during a spacewalk would stop the flow of oxygen to the astronaut, but an emergency backup system would give the crew member time to return to the station's airlock.

During testing in orbit, two fan/pump/separators failed to spin up and both were shipped back to Earth aboard a SpaceX cargo ship earlier this month for detailed analysis. An inspection revealed corrosion around drive shaft bearings. Engineers concluded the corrosion likely was the result of additional testing implemented after water backed up into the helmet of spacewalker Luca Parmitano in 2013.

Based on telemetry, a small amount of bearing corrosion is believed to be present in the fan/pump/separator in Virts' spacesuit. But analysis indicated it was well below the threshold that could cause the unit to fail during use.

As a result, mission managers cleared Virts and Wilmore to press ahead with the first of their three planned spacewalks. Both suits powered up normally Saturday, with no signs of trouble with either fan/pump/separator.

=================================

CAPTION: Barry "Butch" Wilmore, left, and Terry Virts, right, work on the upper surface of the International Space Station's Harmony module Saturday where new cables are being installed to support new commercial crew docking ports. (Credit: NASA TV)

© 2015 William Harwood/CBS News

Astronauts Complete First of Three Spacewalks
by Calla Cofield, Space.com Staff Writer | February 21, 2015 10:32am ET

Astronauts Outside Space Station
Credit: NASA View full size image
Two NASA astronauts are safely back inside the International Space Station today (Feb. 20) after successfully completing the first of three scheduled spacewalks planned to prep the outpost for the arrivals of commercial spacecraft carrying astronauts in the coming years.
Barry "Butch" Wilmore, commander of Expedition 42, and flight engineer Terry Virts successfully completed three scheduled tasks and an extra "get ahead" task during today's spacewalk, with no problems. The two astronauts ventured out of the station at about 8:00 a.m. EST (1300 GMT). They reentered the orbiting outpost just after 2:30 p.m. EST (1930 GMT). Wilmore and Virts are scheduled to perform two more spacewalks in the next eight days.
Today's excursion was Virt's first career spacewalk, and Wilmore's second. Just over an hour into the spacewalk Virts noted to Wilmore, "I feel great man, I feel good! Definitely easier than the pool." (Virts is referring to the Neutral Buoyancy Laboratory (NBL) at Johnson Space Center: a massive swimming pool where astronauts train for work in microgravity). [Quiz: How Well Do You Know the International Space Station?]
The spacewalk was predicted to take around six-and-a-half hours. Five hours after the start of the spacewalk, mission control informed the astronauts that they were approximately 30 minutes ahead of schedule. The astronauts completed one "get ahead" task, which was originally scheduled to be performed during a spacewalk on Feb. 25.
The two NASA astronauts were assisted from inside the station by European Space Agency astronaut Samantha Cristoforetti. In the early morning hours, Cristoforetti helped Wilmore and Virts get into their spacesuits and prepare for the walk.
During today's spacewalk, Wilmore and Virts were given various tasks aimed at preparing the space station for the installation of two international docking adapters that will allow the station to rendezvous with future private space taxis. Last year, NASA selected Space X's Dragon capsule and Boeing's CST-100 to bring future crews to the orbiting outpost.
A NASA illustration of the future location of two new international docking adapters (IDA's), which will allow the orbiting laboratory to link up with private space taxi's.
Credit: NASA
View full size image
In a news conference on Wednesday (Feb. 18), NASA official Karina Eversley described the first task that Wilmore and Virts would be performing today as "the most complicated cable routing task" ever performed in a spacewalk on the International Space Station.
Because so much of their work on today's excursion involved laying and attaching cables, NASA's space station blog dubbed the two astronauts "the cable guys."
The docking adapters for the commercial crewed spacecraft will be launched to the station on two different SpaceX Dragon cargo capsules later this year. Once the private space taxis are in operation, they will allow the station's onboard crew to grow from six members to seven.
Upon returning to the station, Wilmore said, "We've been talking for years about updating the capabilities of the International Space Station, and today we took a giant leap in that direction."
Wilmore and Virts are scheduled to perform additional spacewalks on Feb. 25 and Mar. 1, both starting at 7:10 a.m. EST (1210 GMT). Those spacewalks will also be focused on preparing the station for the new docking adapters.

Copyright © 2015 TechMediaNetwork.com All rights reserved.

Saturday Spacewalk Kicks Off Addition of Commercial Crew Docking Ports to ISS
Feb 21, 2015 by Mark Carreau in On Space

Spacewalking NASA astronauts Barry "Butch" Wilmore and Terry Virts initiated the installation of the first of two planned International Space Station docking ports for future U. S. commercial crew transportation vehicles on Saturday by extending external power, data and thermal control cabling along the orbiting science lab's Harmony and Destiny laboratory modules.
The near seven hour excursion unfolded without difficulties from either of the fan pump separators in the two space suits, a safety concern that emerged in December and January and persisted up to the start of Saturday's spacewalk. Virts experienced a slight buildup of carbon dioxide in his suit from all of the exertion.
NASA's Barry "Butch" Wilmore, left, and Terry Virts install
power, data and heater cables near future ISS docking port
for commercial crew vehicles. NASA photo
The two men started 30 minutes late but surged ahead of schedule, accomplishing some of the work assigned to the second in a series of three excursions over the next nine days.
The fan pump separators are part of the space suit life support system that circulates air and cooling water. The devices originally assigned to Saturday's excursion failed to spin up during late 2014/early 2015 checkouts inside the station's airlock.
The steady performance of the fan pump separators on Saturday was a welcome development.
NASA plans a second and third spacewalk by the two men on Wednesday and Mar. 1 to complete the power, data and thermal control cable task. They also intend two antenna installations and communications cable extensions before Wilmore's scheduled return to Earth. He departs late Mar. 11 with two Russian cosmonauts to conclude 167 days aboard the orbiting science lab.
The primary work site for Saturday's outing was the 16-year-old Pressurized Mating Adapter-2 on the forward end of Harmony, which served as the docking port for NASA's space shuttle fleet until the winged orbiters were retired in mid-2011. Wilmore, the station's current commander, and Virts made five power, data and thermal control connections under two orbital debris shields on either side of PMA-2 and three additional cable connections, including two linkups that were originally scheduled for the second spacewalk.
"I worked up a lather on that one," quipped Wilmore as he marched through the first set of PMA-2 cable connections.
"You guys have done just a superb job," Mission Control told the two men as they entered the home stretch of Saturday's activities.
In all, Wilmore and Virts are to install 10 cables totaling 364 feet over the first two spacewalks to prepare PMA-2 for outfitting with the first of new NASA and Boeing developed International Docking Adapters. The IDAs will serve as the actual mechanical links between the station and future commercial crew vehicles operated by Boeing and SpaceX under NASA contracts.
As Saturday's spacewalk drew to a close at 2:26 p.m., EST.
NASA's goal is to achieve the first commercial crew vehicle docking with astronauts by the end of 2017.
SpaceX is to deliver the first of the IDAs aboard the company's seventh commercial re-supply mission in June. The initial IDA would be installed on PMA-2 during a NASA spacewalk currently planned for July.
This year, NASA also plans to move the identical PMA-3 from the station's Tranquility module to the space facing circumference of Harmony. A second IDA is manifested for delivery aboard another SpaceX resupply mission planned for late this year.
During Wednesday's spacewalk, Wilmore and Virts are to complete the PMA-2 cabling and lubricate the grappling mechanism on the station's Canadian-furnished robot arm. The 58-foot-long mechanical limb will be used to relocate PMA-3 as well as move the station's Leonardo Permanent Multipurpose Module from the Earth facing side of the station's Unity module to the forward end of Tranquility. That move will ensure sufficient clearances for a pair of commercial cargo berthing ports as well as the two commercial crew parking spots.
During the March 1 spacewalk, Wilmore and Virts are to install two communications antennas and string another 400 feet of cabling along the station's port and starboard solar power trusses to support the transmission of navigational data for automated commercial crew rendezvous and dockings.
The source of the balky space suit fan pump separator issue that surfaced in December and January was traced to a corrosion buildup on internal bearings. The corrosion was blamed on water intrusion. Those initial suspicions were confirmed after the two fan pump separators that failed to activate were removed from the space suits and returned to Earth earlier this month aboard the fifth SpaceX Dragon resupply mission. The devices were turned over to United Technologies Corp., the space suit contractor, for evaluation.
The fan pump separators have been activated between spacewalks at an accelerated pace during check outs of cooling system water quality, which has increased the opportunity for exposure of the bearings to water, according to NASA.
The unwanted presence of silica particles in the cooling water was blamed for a July 2013 incident in which water flowed into the space suit helmet worn by European Space Agency astronaut Luca Parmitano. Parmitano retreated to the airlock as water invaded an airflow vent, massing around his eyes, nose and ears. Engineers found small water ports in the pump blocked by silica particles that migrated from water filters. The blockage diverted cooling water into the helmet air flow vent.
The U. S. chaired ISS mission management team cleared Saturday's spacewalk on Thursday after determining any corrosion in the fan pump separators in suits worn by Wilmore and Virts was minimal.
However, NASA's Mission Control refined the governing rules for the excursion by stipulating that work would be halted without further troubleshooting if there were signs of problems with the air and water circulation devices.
In the meantime, NASA has also changed its space suit cooling water quality checkouts to include additional air flow over the bearings as a dry out measure.
Copyright © 2015, Penton. All rights reserved.
AmericaSpace
For a nation that explores
February 21st, 2015
Expedition 42 Spacewalkers Prepare Space Station for Arrival of Commercial Crew Vehicles
By Ben Evans

Astronaut Barry "Butch" Wilmore works at the Pressurized Mating Adapter (PMA)-2, at the extreme "front end" of the Harmony node, during EVA-29 on Saturday, 21 February. Photo Credit: NASA TV
Astronauts Barry "Butch" Wilmore and Terry Virts—two members of the six-strong Expedition 42 crew currently aboard the International Space Station (ISS)—spent six hours and 41 minutes outside the orbital outpost today (Saturday, 21 February), laying and configuring cables in readiness for the arrival of two International Docking Adapters (IDAs), later this year. With Wilmore designated "EV1", bearing red stripes on the legs of his Extravehicular Mobility Unit (EMU), and Virts as "EV2", in a pure white suit, the two men stepped smartly through the tasks of U.S. EVA-29 and set to work on a number of get-ahead tasks for EVA-30. However, rising carbon dioxide levels in Virts' suit led to a prudent decision to bring EVA-29 to a close after all of its objectives and more were accomplished.
As described in AmericaSpace's EVA-29 preview article, this spacewalk had already been pushed back from the late January timeframe by delays in launching SpaceX's CRS-5 Dragon cargo mission and was postponed by 24 hours from Friday, 20 February, due to the need for "added analysis" of the two EMUs. According to ISS Operations and Integration Manager Kenny Todd, speaking at the Johnson Space Center (JSC) in Houston, Texas, last week, the latter surrounded a "Non-Standard" element of open work on the EMUs.
He explained that during a routine coolant loop scrub activity on one of the suits late last year, the Fan Pump Separator (FPS)—which was also part of the root cause of the water-intrusion incident that forced the premature and highly publicized termination of EVA-23 in July 2013—failed to spin-up properly. Troubleshooting identified a possible mechanical binding issue in the FPS and the installation of a new separator has produced no anomalies to date. Unfortunately, last month, the same issue arose in an FPS on another suit. Since it forms part of a single integrated unit, it is inaccessible to the ISS crew, but both faulty units were returned to Earth last week aboard the CRS-5 Dragon and initial evaluation points to a binding issue and areas of corrosion. Water chemistry tests suggest that each time the FPS is powered-up, more water is introduced to the system, and Mr. Todd stressed that his team is looking at improved sampling techniques to avoid damaging the FPS in future. He concluded that both suits were running in fine shape and the corrosion issue is not expected to present a concern for the satisfactory operation of the fan pump separator. However, at the Mission Management Team (MMT) meeting on Thursday, 19 February, it was considered prudent to postpone EVA-29 until additional analysis had been completed.
Barry "Butch" Wilmore (left) led EVA-29 and will also lead next week's EVA-30, whilst Terry Virts (right) will lead EVA-31. Photo Credit: NASA
This particular spacewalk is of great importance to the future of the ISS. Its tasks were labeled "IDA Prep" in NASA's most recent Flight Planning Integration Panel (FPIP) documents, and form part of the critical "IDA Pathway", which was expected to see Wilmore and Virts laying cables and utilities for the two new docking adapters. These are expected to be delivered to the station aboard SpaceX's CRS-7 and CRS-9 Dragon missions in June and December 2015, respectively. As outlined in an earlier AmericaSpace article, two Pressurized Mating Adapters (PMAs-2 and 3) will outfitted with the IDAs, thereby converting them from the shuttle-era Androgynous Peripheral Attach System (APAS)-95 docking interface into the new Soft Impact Mating and Attenuation Concept (SIMAC), for use by Boeing's CST-100 and SpaceX's Dragon V-2 vehicles.
PMA-2 currently resides at the forward port of the Harmony node—the extreme "front end" of the ISS—and will be fitted with IDA-1. Meanwhile, PMA-3 is presently situated at the forward port of the Tranquility node, but will be robotically transferred to Harmony's space-facing (or "zenith") port in the October 2015 timeframe, in order to accept IDA-2 in December. However, in addition to the need for two ports for Commercial Crew vehicles, two ports are also needed for unpiloted visiting craft, including SpaceX Dragons, Orbital Sciences' Cygnus and Japan's H-II Transfer Vehicles (HTV). In order to open up a second set of ports, this requires the movement of the 22-foot-long (6.7-meter) Leonardo Permanent Multipurpose Module (PMM) in late July from its current position at the Earth-facing (or "nadir") port of the Unity node to the forward port of the Tranquility node. This will "open up" a new Common Berthing Mechanism (CBM) at Unity nadir to join the existing interface at Harmony nadir for unpiloted visiting vehicles, as well as ensuring that sufficient clearance is available for the arrival of future craft.
Final preparations got underway early Saturday morning, when Wilmore and Virts were assisted into the Quest airlock by their Expedition 42 crewmates Anton Shkaplerov of Russia and Italy's first woman in space, Samantha Cristoforetti. Following a slight delay, they conducted 60 minutes of "pre-breathing" on masks, during which time the inner "equipment lock" of the airlock was depressed from its ambient 14.7 psi down to 10.2 psi. Upon completion of this protocol, Wilmore and Virts donned and purged their bulky EMUs and the airlock's atmosphere was repressurized to 14.7 psi. This permitted them to enter a nominal pre-breathing regime, lasting 50 minutes, followed by another 50 minutes of In-Suit Light Exercise (ISLE). The latter was first trialed on the STS-134 shuttle mission in May 2011 and involved the spacewalkers flexing their knees for about four minutes, resting for 60 seconds, then repeating until the 50 minutes are up. This technique serves to rapidly remove nitrogen from their bloodstreams, thereby preventing a potentially fatal attack of the "bends."
Terry Virts undergoes a dry run for his EVA suiting procedure, ahead of EVA-29. Photo Credit: Terry Virts/NASA/Twitter
At length, the fully-suited pair and their equipment—including the Simplified Aid for EVA Rescue (SAFER) units, affixed to the lower section of their life-sustaining backpacks—were transferred by Cristoforetti from the equipment lock into Quest's outer "crew lock." Another delay was created by an issue with the primary data path on Virts' suit, which necessitated additional time for communications checks. At length, the hatches between the two locks were closed and depressurization got underway. When it reached 5 psi, the process came to a halt for standard leak checks, after which depressurization continued until the crew lock reached a condition of near-vacuum. The EVA officially began when Wilmore and Virts transferred their suits' critical life-support utilities over to internal battery power. EVA-29 kicked off at 7:45 a.m. EST, with Wilmore pushing open Quest's outer hatch and departing the airlock, followed by Virts.
Wilmore brought out an IDA Port Cable Bag and Crew Lock Bag and Virts will carry an identical set of bags for the starboard side. When both men were outside, they closed the thermal cover of Quest and pressed immediately into critical "buddy checks" to ensure that their suits and safety tethers were properly configured, as well as carrying out an inventory of their tools. Wilmore translated along the Crew and Equipment Translation Aid (CETA) Spur towards the port-zenith side of the U.S. Destiny laboratory, and eventually reaching the forward end cone of Harmony. Meanwhile, Virts followed a slightly different path, heading around the External Stowage Platform (ESP)-2 on the port side of Quest, and joined Wilmore at the front end of Harmony.
Despite some initial difficulties for Virts, the duo successfully stowed their bags and installed wire-tie restraints along routes where the cables were to be laid. Wilmore installed eight of the ties and Virts completed a total of 11. Wilmore moved the existing PMA-2 umbilical cabling out of the way, preparatory to the removal of two Micrometeoroid Orbital Debris (MMOD) shields. Using a Pistol Grip Tool (PGT), they released three bolts holding the port-side shield in place and removed it. Virts then opened the Port IDA Cable Bag and Wilmore disconnected four existing cables—previously used during shuttle dockings and still employed to provide PMA-2 heater power—from beneath the shield and Virts passed him the four new IDA cables to install. They reattached the MMOD shield, then moved to the starboard side of Harmony's forward end cone, where they exchanged roles and Virts led the disconnection of existing cables and the installation of IDA cables.
EVA-29 involved very intricate work with a large amount of delicate cable to provide power and data to the International Docking Adapters (IDAs). Photo Credit: NASA
Before leaving the starboard cable bag, Wilmore retrieved the Purple Cable—the longest cable, in fact, at about 43 feet (13 meters) in length—and brought it to the port side of Harmony, where he attached it to Handrail 343 and uncoiled it along a "path" towards Destiny, in order to make a pair of connections. After some difficulty, he stowed one "leg", which will eventually lead to PMA-3 after its relocation, and then secured the second leg with wire ties to await the arrival of IDA-1. Elsewhere, Virts unpacked and routed cables from the Port IDA Cable Bag to restore power and telemetry for the PMA-2 heaters, each of which carries "legs" destined for the forward end of the adapter, on zenith and nadir faces. Wilmore handled the port nadir route and Virts the starboard zenith route.
By 5.5 hours into EVA-29, it seemed likely that the spacewalk would be extended to seven full hours, in order to complete all remaining cable work at the forward end of Harmony, thereby pressing into the early tasks originally earmarked for the upcoming EVA-30. Under this plan, Virts would work his way steadily aft, towards the forward end cone of the Destiny laboratory, where he was to set some inhibits in place in order to avoid any "hot" mates or demates of cables during the remainder of the IDA Prep work. Part of the setting of these inhibits required him to unplug four connectors to remove power, but after some difficulty an increase in carbon dioxide levels in his suit was noted. Told to settle down, Virts pressed on, but the issue with his suit remained and prompted Flight Director Tony Ceccacci to decide to call it a day. All of the EVA-29 tasks had been completed and a fair portion of get-ahead work has been laid in readiness for next Wednesday's EVA-30.
The success of today's spacewalk was not lost on the NASA and international astronauts, assigned and unassigned, who undoubtedly watched, enviously, from the ground. "Working w/cable on a spacewalk…a very challenging/exhausting task," exulted Astronaut Candidate (ASCAN) Anne McClain. "These guys laid 340 feet of cables in six hours 41 minutes. Wow!" Fellow astronaut Ricky Arnold—who performed two EVAs on shuttle mission STS-119 in March 2009—welcomed Virts to the spacewalking fraternity, whilst British astronaut Tim Peake noted that "laying cables is tough work on the hands". Nicole Stott, who was selected as an astronaut in the same class as Wilmore and Virts, back in July 2000, paid homage to their class nickname: "Awesome work…Go Bugs!" Other former astronauts and veteran spacewalkers, including Mike Lopez-Alegria and Clay Anderson, also chimed in via Twitter, expressing their fervent wish to have taken part in today's EVA. In response to Anderson's light-hearted plea, Canada's most experienced spacewalker, Dave Williams, tweeted: "If you ever need an EV2, give me a call. I'll be your wingman, anytime!"
Seen from the multi-windowed cupola by Italian astronaut Samantha Cristoforetti, Terry Virts works through his final tasks of EVA-29. Photo Credit: Samantha Cristoforetti/Twitter/NASA
Returning inside the Quest airlock and closing the hatch, EVA-29 ended at 2:26 p.m. EST, after six hours and 41 minutes. Today's excursion marked the 185th spacewalk dedicated to ISS construction and maintenance, since the inaugural EVA by STS-88 astronauts Jerry Ross and Jim Newman to install cables and utilities between the U.S. Unity node and the Russian-built Zarya functional control block on 7 December 1998. Since then, spacewalkers have toiled in the near-total vacuum outside the station to create the grandest engineering accomplishment in history. In total, they have spent 1,159 hours and eight minutes in pressurized suits, working in the harshest environment known to humanity.
This was Wilmore's second EVA—following his inaugural career excursion in October 2014—and he had previously accrued about six hours and 34 minutes of spacewalking time, whilst Virts had not previously ventured outside his spacecraft in orbit. With today's six-hour and 41-minute EVA-29, Wilmore has now accumulated 13 hours and 15 minutes of spacewalking time, which moves him from 166th place to 116th on the list of 211 spacewalkers from the United States, Russia, France, Germany, Japan, Switzerland, Canada, Sweden, China and Italy, since Alexei Leonov's pioneering excursion, way back in March 1965. Having completed his first career EVA, Virts now sits in 164th place on the list.

Copyright © 2015 AmericaSpace - All Rights Reserved