Astronauts Install New Solar Array Outside International Space Station – Spaceflight Now

NASA astronauts Josh Cassada and Frank Rubio headed outside the International Space Station on Saturday for a seven-hour spacewalk to install and deploy a new deployable solar array recently delivered by a cargo ship from SpaceX.

Cassada and Rubio, both on their first space flights, began the spacewalk at 7:16 a.m. EST (1216 GMT) on Saturday. The start of the excursion was officially marked when the astronauts changed into their spacesuits at the battery.

The astronauts moved from the space station’s Quest airlock to the starboard, or right, side of the lab’s solar power armor, where the station’s robotic arm placed two new ISS Roll-Out Solar Array, or iROSA, units earlier this week after being removed from the trunk of a SpaceX Dragon cargo capsule. The Dragon spacecraft delivered the solar arrays to the space station on November 27, along with several tons of supplies and experiments.

The new solar array blankets were wrapped around coils and unrolled like a yoga mat once installed on a mounting bracket in starboard section 4, or S4, of the electrical armature of the ‘space station, which measures more than the length of a football field from end to end. to finish.

Astronauts initially worked to remove one of the two newly delivered iROSA units from its mount by loosening screws and releasing restraints. Cassada positioned himself on a foot stand at the end of the Canadian-built robotic arm and held the coils of the solar array with his hand as the arm moved him into the S4 armature.

The two spacewalkers placed the iROSA unit on a prepositioned mounting bracket during a previous spacewalk. They unfolded the iROSA unit on its hinge and then installed screws to secure it in place. Cassada and Rubio attached electrical connectors to connect the new iROSA unit to the space station’s electrical system. Next, they laid a Y-wire to route the power generated by both the new deployable solar array and the original S4 solar panel to the lab’s electrical grid.

The mounting bracket connects the new arrays to the station’s feed channels and rotary joints, which keep the solar wings pointed at the sun as the spacecraft races around Earth at more than 17,000 mph.

The International Space Station has eight power channels, each powered by electrical power generated from a solar array wing that extends from the station’s spine. The new solar array deployed on Saturday will produce electricity for the space station’s 3A power channel.

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 panels has degraded over time. NASA is upgrading the space station’s power system with the new deployed solar arrays, at a cost of $103 million, which will partially cover six of the station’s original eight solar panels.

When all six iROSA units are deployed on the station, the power system will be capable of generating 215 kilowatts of electricity to support at least another decade of science operations. The upgrade will also accommodate new commercial modules planned for launch to the space station.

The first pair of new deployable solar panels were launched to the space station last year and were installed over the station’s oldest set of original solar panels in the P6 armor section, located at the left end of the outpost’s power armour. Two more iROSA units are scheduled to launch on a SpaceX resupply mission next year.

The new solar panels were supplied to NASA by Boeing, Redwire and a team of subcontractors.

Once the new iROSA unit was mechanically and electrically integrated into the station’s S4 armor, the astronauts released clamps keeping the deployable solar array coiled in its launch configuration. This allowed the blankets to gradually unwind by using the tension energy in the composite gullies that support the solar blanket. The deployment mechanism design eliminates the need for motors to drive the solar array.

“It’s starting to move,” one of the astronauts radioed into mission control, prompting applause from the support team in Houston.

“This is amazing,” Cassada said. “Yeah, that’s great,” Rubio said.

The carbon fiber support arms were rolled against their natural shape for storage during launch.

The solar array took about 10 minutes to unroll to its fully extended configuration, approximately 63 feet long and 20 feet wide (19 by 6 meters). That’s about half the length and half the width of the station’s current solar arrays. Despite their smaller size, each of the new arrays generates roughly the same amount of electricity as each of the station’s existing solar panels.

Once the blanket was deployed, the astronauts adjusted the tension screws to secure the iROSA blanket in place.

The astronauts then returned aboard the space station fairing to prepare another iROSA unit, which will be installed in the left side P4 fairing section on a spacewalk tentatively scheduled for December 19

With their tasks complete, Cassada and Rubio returned to Quest’s airlock and closed the hatch. They began repressurizing the Airlolk compartment at 2:21 pm EST (1921 GMT), completing the 7 hour 5 minute spacewalk.

Saturday’s spacewalk was the second in Cassada and Rubio’s career, and the 256th spacewalk since 1998 in support of the assembly and maintenance of the International Space Station.

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