Astronauts complete spacewalks in preparation for new solar arrays for the International Space Station – Spaceflight Now

Astronauts Koichi Wakata (left) and Nicole Mann (right) outside the International Space Station on Friday’s spacewalk. Credit: NASA

Japanese astronaut Koichi Wakata and NASA astronaut Nicole Mann donned their suits and floated outside the International Space Station on Friday for a journey through space to prepare the laboratory for the arrival of another pair of new solar arrays later this year.

The astronauts switched their spacesuits to internal battery power at 8:14 a.m. EST (1314 GMT) Friday to celebrate the official start of the spacewalk, the first of the year on the space station. They floated out of the Quest airlock to begin collecting instruments and headed to the starboard, or starboard, side of the station’s electric truss.

Wakata and Mann completed the installation of a mounting bracket near one of the space station’s eight solar arrays, connected to power channel 1B. Work on this mission began on a previous spaceflight. Then the astronauts got to work attaching another solar array mounting frame to power channel 1A.

The two power channels the astronaut worked on Friday are located on the right side of the space station’s solar-powered truss, which stretches the length of a football field. Channel 1B is in the S6 truss section on the far right of the strong truss, and Channel 1A is in the next inboard section, labeled S4.

The mounting frames, called modification kits, will support the attachment of new solar arrays that are slated to be delivered to the space station later this year on a SpaceX Dragon cargo ship. SpaceX has already launched four of the deployed solar arrays on two previous Dragon resupply missions in June 2021 and in November 2022.

Wakata and Mann finished most of the work installing the adjustment assembly on channel 1B, but due to time constraints, ground teams instructed the astronauts to return to the airlock before they could finish tightening the screw on the final strut of the second stabilization bracket. This task will be completed in future spacewalks.

The astronauts began repressurizing the Quest airlock at 3:35 p.m. EDT (2035 GMT), marking the end of the 7-hour, 21-minute spacewalk.

This diagram shows the strong truss of the International Space Station. Sections S4 and S6 are the focus of Friday’s spacewalk. Credit: NASA

Friday’s spacewalk was part of a series of flights to prepare for and install the International Space Station’s new solar arrays, or iROSA modules. Built by Redwire, the iROSA modules are designed to increase the space station’s ability to generate electricity as the efficiency of the lab’s original solar panels declines with age.

NASA wants to install the mounting frame for each new solar array wing early. The astronauts then go out on excursions into space to manually attach each new solar array that is rolled out as they arrive aboard a SpaceX cargo ship.

NASA astronauts Frank Rubio and Josh Casada completed two spacewalks in December to install and launch their newest solar arrays. Station crew members will do similar work later this year when SpaceX takes delivery of the last two solar arrays to be rolled out on a cargo mission tentatively scheduled for launch in June.

The solar arrays are launched around a spool to fit into the cargo box of the Dragon spacecraft. Once deployed, it spans 63 feet long and 20 feet wide (19 by 6 meters), roughly half the length and half the width of the station’s original solar panels. The solar array blanket will spread out at an undisclosed angle relative to the original solar panel on each gear, allowing sunlight to illuminate the new and old arrays.

Despite their small size, each of the new arrays generates roughly the same amount of electricity as each of the station’s existing solar panels.

Japanese astronaut Koichi Wakata and astronaut Nicole Mann. Credit: NASA Television

The International Space Station has eight power channels, each of which is fed by electrical energy generated from a single solar array wing that extends from the station’s backbone.

The original solar panels were launched on four space shuttle missions from 2000 to 2009. As expected, the efficiency of the station’s original solar arrays deteriorated over time. NASA is upgrading the space station’s power system with new solar arrays — at a cost of $103 million — that will partially cover six of the station’s eight original solar panels.

When all six iROSA modules are deployed to the station, the power system will be able to generate 215 kilowatts of electricity to support at least another decade of science operations. This represents a 30% increase in power generation capacity. The booster will also accommodate the new commercial modules planned for launch on the space station.

Friday’s spacewalk was Wakata Woman’s first, and the 258th spacewalk overall since 1998 in support of space station assembly and maintenance. Wakata, classified as an EV1 astronaut on Friday, is a veteran astronaut on his fifth trip to space. MAN, designated EV2, on its first spaceflight.

Mann and Wakata launched Oct. 5 on a SpaceX Crew Dragon spacecraft with crewmates Josh Cassada and Russian cosmonaut Anna Kikina. They’re scheduled to return to Earth in early March, following the arrival of another team of four astronauts and cosmonauts for the upcoming SpaceX crew launch.

NASA astronauts Frank Rubio, Russian cosmonauts Sergey Prokopyev and Dmitry Petlin round out the seven-man crew on the International Space Station. They arrived at the space station in September aboard the Russian Soyuz spacecraft.

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