Two NASA astronauts will venture outside the International Space Station (ISS) early Wednesday to tend to long-awaited upgrades to Europe’s Columbus lab and prepare for the installation of upgraded solar arrays on the sprawling orbital complex. Seasoned spacewalker Mike Hopkins—a veteran of two previous sessions of Extravehicular Activity (EVA), totaling 12 hours and 58 minutes—and “rookie” Victor Glover will depart the station’s Quest airlock at about 7 a.m. EST for approximately 6.5 hours.
The principal focus for the two men is to complete cable and antenna rigging for the European Space Agency’s (ESA) Bartolomeo payloads-anchoring platform, delivered to the station last March aboard SpaceX’s CRS-20 Dragon cargo ship and robotically installed onto the exterior of Columbus.
Capable of holding a single “passive” and as many as 12 “active” payloads, Bartolomeo was built by Airbus Defence and Space and originally known as the Commercial External Payload Hosting Facility on ISS (CEPHFISS), before it was named in honor of Christopher Columbus’ younger brother, the Genoa-born Italian explorer Bartholomew Columbus (1461-1515).
Bartolomeo—which, appropriately, adopts the Italian spelling of the younger Columbus’ name—offers power management, payload commanding, data management, storage and downlink capability, as well as flight environment determination functions for a wide range of experiments and facilities on the forward-facing side of the Columbus lab. The 22-foot-long (6.8-meter) lab is affixed to the starboard port on the station’s Harmony node.
Following its delivery to the ISS, the 1,032-pound (468 kg) Bartolomeo was robotically extracted from Dragon’s unpressurized “trunk” by means of the station’s 57.7-foot-long (17.6-meter) Canadarm2 and its installation onto Columbus was completed last 2 April. Early expectations for an EVA late last spring to complete the installation of cables in support of the platform and the Columbus Ka-Band Antenna (Col-KA) were indefinitely postponed, as Commercial Crew Program delays forced the station for several months to a staff of only three crew members.
But with the arrival of regular Commercial Crew operations in the second half of 2020—and a present ISS staff of seven—the availability of U.S. Operational Segment (USOS) personnel to support the EVA is now in place.
Four spacewalks involving Hopkins and Glover, as well as their fellow Expedition 64 crewmates Soichi Noguchi and Kate Rubins, are planned over the next several weeks to attend to essential ISS upgrades and prepare for the installation of new solar arrays over the next year or two. Work to ready the station’s Quest airlock for the EVAs has been ongoing for several weeks, with a newly-refurbished U.S. Extravehicular Mobility Unit (EMU)—the veteran EMU No. 3015—having been delivered to the station last month aboard SpaceX’s CRS-21 Dragon cargo ship.
This particular suit was worn during 30 spacewalks, beginning with Jerry Ross’ historic outing on STS-88 in December 1998 on the inaugural shuttle ISS construction mission and most recently by Japan’s Aki Hoshide back in August 2012. It was returned to Earth aboard SpaceX’s CRS-3 Dragon in the spring of 2014 and is now back aboard the station for its next phase of operational service.
Last month, Hopkins and Noguchi removed EMU No. 3015 from the CRS-21 Dragon and replaced it with EMU No. 3008, which returned to Earth in January for refurbishment and maintenance. They also worked to clean up the Quest airlock, assemble tools and scrub coolant loops on the space suits and earlier this month Hopkins, Glover, Rubins and Noguchi participated in procedures reviews and conferences with EVA specialists on the ground.
With Noguchi having logged three EVAs in his careers, and Hopkins and Rubins two apiece, Glover is getting ready for his first pair of spacewalks. Last week, he serviced life-support components on the suits and worked with Hopkins on a series of computer-aided tasks to walk him through activities and procedures. Elsewhere, Rubins and Noguchi joined them to practice robotics maneuvers during the EVAs.
And Glover himself will be the subject of one such robotic maneuver, shortly after he emerges from the airlock early Wednesday. First out will be Hopkins, designated “EV1” and whose suit is characterized by red stripes on its legs. Meanwhile, Glover will move firstly to External Stowage Platform (ESP)-2 to collect a portable foot restraint and board Canadarm2.
They will carry the refrigerator-sized Columbus Ka-Band Antenna (COL-Ka), which arrived on the ISS aboard Northrop Grumman Corp.’s NG-13 Cygnus cargo ship in February 2020, out to the work site on the starboard side of the station. They will work together to remove bolts on exterior lab panels, before installing COL-Ka, after which Glover will route cabling for the new antenna and plug it into Columbus.
It is expected that the British/Italian-built COL-Ka upgrade will provide data speeds of up to 50 Mbits/sec for downlink capability and up to 2 Mbits/sec for uplink capability. This will permit astronauts and researchers to benefit from a direct link with control centers in Europe at home broadband speeds, “delivering a whole family’s worth of video streaming for science and communications”, according to ESA.
Since its arrival in February 2008, Columbus has been largely dependent for its data needs on U.S. systems, but COL-Ka will offer faster and independent communications “for another decade to come”. It is also expected to serve as a pathfinder for the technologies on the ESA-provided European System Providing Refueling, Infrastructure and Telecommunications (ESPRIT) module, whose components are expected to be launched to the fledgling Lunar Gateway later this decade.
Following the COL-Ka installation, Hopkins and Glover will move to the Bartolomeo platform itself. They will open up a series of clamps in order to remove electrical and other cables to activate the new facility. Hopkins will remove another set of cables to hook up Bartolomeo’s antenna and remove its protective cover, with Glover—riding Canadarm2—due to jettison the unneeded cover overboard.
The pair will close out their 6.5-hour EVA by heading to the far-port side of the station, at the outboard P-6 truss, to remove a pair of “H-Fixtures” to make way for the planned installation of new ISS Roll-Out Solar Arrays (iROSAs), later this year and into 2022. Described by Lead Spacewalk Officer Sarah Korona as “a robotics interface that is no longer needed”, these fixtures were originally used for ground-based processing of the arrays and are no longer needed.
One H-Fixture was removed—though not entirely smoothly—from Power Channel 3B of the outboard S-6 truss by spacewalkers Chris Cassidy and Bob Behnken on the most recent U.S. spacewalk (designated U.S. EVA-68) last July. An attempt earlier that month had met with difficulties and eventually on 21 July Cassidy was obliged to use pliers to work the stubborn H-Fixture free.
“One H-Fixture (3B) was removed as a target of opportunity on EVA-68 in July 2020,” NASA’s Gary Jordan told AmericaSpace earlier in January. “The three remaining H-Fixtures (Power Channels 1A, 3A and 4A) are planned to be removed during spacewalks at the start of 2021.”
A successful EVA on Wednesday will mark Hopkins’ third spacewalk, bringing his cumulative time in the vacuum of space to a little less than 20 hours. Glover, who already secured a record late in December for having logged more time in space than any other African-American astronaut, will also become the first African-American to perform an EVA in almost a full decade. The last person to do so was STS-133’s Al Drew, during the final voyage of shuttle Discovery in March 2011.