Less than a week after their scheduled 23 March arrival at the International Space Station (ISS), Expedition 55/56 astronauts Drew Feustel (EV1) and Ricky Arnold (EV2) will participate in a 6.5-hour Extravehicular Activity (EVA) on Thursday, 29 March. According to NASA, the spacewalk—designated “U.S. EVA-49”—will involve Feustel and Arnold completing a series of tasks in support of an upcoming science payload and further enhancing the station’s communications envelope for upcoming Commercial Crew vehicles, via the Common Communications for Visiting Vehicles (C2V2) architecture.
Present plans call for Feustel and Arnold to launch from the Baikonur Cosmodrome in Kazakhstan, shoulder-to-shoulder with Russian cosmonaut Oleg Artemyev, aboard Soyuz MS-08 at 10:45 p.m. local time (12:45 p.m. EDT) on Wednesday, 21 March, after which the trio will embark on a two-day and 34-orbit rendezvous profile to reach the ISS. They will dock at the station’s space-facing (or “zenith”) Poisk module at 3 p.m. EDT on Friday, 23 March, joining the incumbent Expedition 55 team of Commander Anton Shkaplerov and his crewmates Scott Tingle and Norishige Kanai, who have been aboard since December. Less than a week later, the outer hatch of the Quest airlock will open and Feustel and Arnold will begin the first EVA of their 5.5-month increment.
It will be one of the shortest intervals between the arrival of a new long-duration crew and a spacewalk in ISS Program history and is being conducted to take advantage of a break in visiting vehicle traffic, ahead of the launch of SpaceX’s CRS-14 Dragon in early April. In fact, an EVA this soon after a crew’s arrival was most recently mirrored during the unscheduled EVA of Expedition 46/47 crewman Tim Kopra, alongside Scott Kelly in December 2015.
“Feustel and Arnold are experienced spacewalkers, with Feustel having conducted six previous EVAs and Arnold having conducted two,” NASA’s Rob Navias told AmericaSpace on Monday. “No issues with them going EVA so soon after arriving on-board.” In fact, Mr. Navias drew parallels between the frequency of crew members going EVA within days of launch, back in the shuttle era.
Indeed, the astronauts bring a wealth of spacewalking expertise to the table. Feustel, who flew aboard the final Hubble Space Telescope (HST) servicing mission, STS-125 in May 2009 and shuttle Endeavour’s STS-134 swansong in May 2011, has accrued 42 hours and 18 minutes in his six career EVAs. Arnold, who previously served aboard shuttle Discovery on STS-119 in March 2009, spent 12 hours and 34 minutes spacewalking to assemble and activate the station’s S-6 solar arrays, batteries and radiators. Preparing the astronauts for their EVA will be Kanai as “Suit IV”, fulfilling the “intravehicular” role. He will be joined by Tingle to operate the station’s 57.7-foot-long (17.6-meter) Canadarm2 robotic arm throughout the spacewalk.
The 29 March EVA will be the 49th spacewalk conducted in U.S.-built Extravehicular Mobility Unit (EMU) suits, from the station’s airlock, and in the absence of a docked Space Shuttle, since February 2002. It is the fourth EVA to be performed outside the station in 2018, following a Russian spacewalk last month and two U.S. excursions in January and February, involving Expedition 54 crewmen Aleksandr Misurkin, Anton Shkaplerov, Mark Vande Hei, Scott Tingle and Norishige Kanai. “The EVA is one of three potentially happening this spring,” NASA’s Dan Huot told AmericaSpace. “The timing, as usual, is being managed around cargo flights and crew rotations. With SpaceX set to arrive in early April, the science aboard will dominate the crew’s time before it returns. The other major task being planned for an upcoming EVA will be relocating a failed Pump Flow Control Subassembly (PFCS) and some additional High-Definition (HD) camera swaps.”
The primary task for Feustel and Arnold on U.S. EVA-49 is to install additional wireless communications equipment onto the exterior of the Tranquility node, ahead of the arrival of the Jet Propulsion Laboratory’s ECOsystem Spaceborne Thermal Radiometer on Space Station (ECOSTRESS), which is due to launch aboard the CRS-15 Dragon in early June. This instrument, which will be robotically installed onto the Exposed Facility (EF) of Japan’s Kibo lab, is expected to investigate the response of the terrestrial biosphere to changes in water availability, together with impacts on the global carbon cycle. The experiment also seeks to understand if agricultural vulnerability can be reduced through advanced monitoring of agricultural water consumptive use and improved drought estimations. Using a multispectral thermal infrared radiometer, ECOSTRESS will measure Earth’s surface and acquire the most detailed temperature profiles ever acquired from space. It will even be able to measure the temperature of an individual farmer’s field.
Feustel and Arnold’s work on 29 March will assist with upcoming ECOSTRESS data-gathering methods, as well as enhancing the communications envelope for upcoming Commercial Crew vehicles, via the Common Communications for Visiting Vehicles (C2V2) architecture. Additionally, the two spacewalkers will remove a pair of flex-hoses from one of the station’s port-side radiator beam valve modules and swap-out cameras on the Camera Port-8 (CP-8) assembly on the P-1 truss. In the event that Feustel and Arnold complete their tasks ahead of the timeline, a number of “get-aheads” may also be assigned to them. Specifically, they may be asked to install handle bars on the port-side and starboard-side Radiator Grapple Bars (RGBs) and break torque on bolts on a spare pump module on External Stowage Platform (ESP)-2 and a flex-hose rotary coupler on the S-1 truss. “This would economize time for these tasks,” Mr. Navias told AmericaSpace on Monday, “for R&R work in the future.”
Assuming U.S. EVA-49 runs to its expected 6.5-hour timeline, Feustel will wrap up his seventh career spacewalk with a total of almost 49 hours. Currently the world’s 20th most experienced spacewalker, he should push himself into the Top Ten.