![A sixth iROSA is unrolled at the International Space Station during a June 15, 2023, spacewalk. This is one of six new solar arrays added to the space station over the last two years. Credit: NASA](https://www.spaceflightinsider.com/wp-content/uploads/2023/06/Fyrk3-YWABI_6O5.jpg)
A sixth iROSA is unrolled on the International Space Station during a June 15, 2023, spacewalk. That is certainly one of six recent solar arrays added to the space station over the past two years. Credit: NASA
During a pair of spacewalks over the past week, two astronauts accomplished installing a set of latest solar arrays outside the International Space Station.
This was a part of a yearslong technique of upgrading the outpost’s power system to enable it to have sufficient power-generating capability through its planned end of life in 2030.
Called an ISS Roll-Out Solar Array, or iROSA, the unique plan was for six to be installed over six of eight legacy arrays. The primary two pairs were delivered inside SpaceX’s Dragon cargo ship in 2021 and 2022.
The ultimate of the initial sets was delivered to the ISS when CRS-28 cargo Dragon docked to the outpost on June 6, 2023, roughly a day after its launch from Kennedy Space Center in Florida.
![The iROSA on the S6 truss being unrolled after its installation was completed. Credit: NASA](https://www.spaceflightinsider.com/wp-content/uploads/2023/06/Fyrk5ITWABAMB_D-655x368.jpg)
The iROSA on the S6 truss being unrolled after its installation was accomplished. Credit: NASA
Each iROSA was in a cradle that was faraway from the trunk and placed on a brief location on the mobile base system near the starboard side of the outpost’s 356-foot (109-meter) long truss.
It could be as much as two members of the seven-person Expedition 69 crew to go outside on two separate spacewalks to put in the brand new devices of their planned locations on the starboard side of the truss.
NASA astronauts Woody Hoburg and Steve Bowen got the duty. They’d alternate leadership in the course of the outings with Bowen being the lead spacewalker during June 9’s US. EVA-87 and Hoburg during June 15’s U.S. EVA-88.
Each spacewalks would see the duo work to bring an iROSA to the work area first using the robotic Canadarm2, operated via Emirati astronaut Sultan Al Neyadi on the inside the space station.
With Hoburg at the tip of the arm and holding onto the rolled-up array, Canadarm2 could be maneuvered closer to the work area. Then the duo would pass the array forwards and backwards to “walk” it to the ultimate location.
For the June 9 spacewalk, an iROSA was installed on 1A power channel on the starboard S4 truss. In the course of the June 15 outing, an iROSA was installed on the 1B power channel on the starboard S6 truss.
Each iROSA is 60 feet long by 20 feet wide (18.2 meters long by 6 meters wide) once fully unrolled. They’re more advanced and efficient than the present arrays, thus requiring less solar gathering area. Using a modification mounting kit, they were installed over the present legacy arrays, that are 112 feet long and 39 feet wide (24 meters long and 12 meters wide).
The legacy arrays were launched over the course of several space shuttle missions between 2000 and 2009, each having a roughly 15-year lifespan. Unnecessary to say, the oldest arrays are well past that limit and have begun showing signs of degradation over time.
With six iROSAs installed, the ability capability of the ISS has increased by about 30%, in line with NASA, to about 250 kilowatts of power output. The outpost is currently consuming about 75 to 90 kilowatts.
NASA said it’s working with Boeing and Redwire (the corporate that built the arrays) to ready two more iROSAs for launch within the 2025 time-frame. Those would likely go over the remaining two legacy arrays yet to be covered, one on either side of the truss.
![The location of all six iROSA devices currently installed at the International Space Station. Credit: NASA](https://www.spaceflightinsider.com/wp-content/uploads/2020/07/iRosa_future-e1611770958964-655x360.jpg)
The placement of all six iROSA devices currently installed on the International Space Station. Credit: NASA
For the June 15 spacewalk — U.S. EVA-88 — the duo was in a position to complete all their tasks faster than expected and get several get-ahead items done in preparation for future spacewalks.
In total U.S. EVA-87 lasted 6 hours and three minutes while U.S. EVA-88 lasted 5 hours and 35 minutes.
Bowen was on his tenth spacewalk, which ties him with former NASA astronauts Michael Lopez-Alegria, Bob Behnken, Peggy Whitson and Christopher Cassidy for probably the most EVAs by a NASA astronaut. Nevertheless, his cumulative spacewalking time is 65 hours and 57 minutes, a pair hours shy of Lopez-Alegria’s record, putting him third behind Alegria’s second place rank.
The record for probably the most spacewalks is former Russian cosmonaut Anatoly Solovyev. He performed 16 spacewalks over his profession for a cumulative time of 82 hours, 22 minutes.
For Hoburg, his two profession spacewalks bring him to 11 hours and 38 minutes.
To date in 2023, there have been eight spacewalks, six of which have been performed by members of the Expedition 69 crew. There may be one other spacewalk expected later this month to be conducted by Russian cosmonauts.
Overall for the whole ISS program since 1998, there have been 265 EVAs in support of the outpost’s assembly and maintenance. That totals some 70 days, 3 hours and 27 minutes.