Astronauts Josh Kasada and Frank Rubio floated outside the International Space Station on Saturday to install a third roll-out solar array blanket as part of an ongoing power system upgrade, leaving the lab behind. isolated the damaged circuit in one of the arrays.
Floating in the Quest’s airlock compartment, Casada and Rubio switched their spacesuits to battery power at 7:16 a.m. ET, officially beginning their scheduled seven-hour spacewalk. The 256th time was spent building and maintaining the station, and this year is his 11th so far.
For identification purposes, Casada, callsign EV-1, wears a red-striped suit and uses helmet camera number 22, while Rubio, EV-2, is marked with helmet camera number 20. No suit.
The purpose of this excursion is to install a new set of ISS Deployable Solar Array Blankets (IROSA), which were delivered to the space station aboard the SpaceX Dragon cargo ship last month.
The station is equipped with four giant solar wings, two at each end of a football-field-length truss. The array rotates like a paddle wheel as the lab flies into space to maximize power generation.
Each of the four wings consists of two sets of solar cells extending in opposite directions from a central hub. Eight sets of blankets power the eight main circuits or power channels to operate the lab system and recharge the batteries during the day. The battery provides power when the orbit is dark.
The first set of first equipment blankets on the far left of the power plant’s power truss have been in operation for over 20 years. Later wings were added in 2006, 2007 and 2009. They all degrade from years of aging in the space environment and don’t produce as much power as they did when new.
In a $103 million upgrade, NASA is installing a smaller, stronger IROSA blanket to augment the output of the lab’s eight older original instrument blankets.
The first two IROSA blankets were attached to the left outboard array (the oldest set on the station) during the 2021 spacewalk. Casada and Rubio planned to add one of his two new IROSAs to the right inboard wing to augment the power channel. 3A.
A second new IROSA will be mounted on the left inboard array during the December 19 spacewalk to boost power channel 4A. The final set of IROSA will be delivered to the station next year.
The IROSA was tightly rolled up and folded in the middle for launch. After attaching the assembly to the previously attached brackets, Cassada and Rubio deploy her 3A IROSA, lock it open to release the restraints, and place the blanket so he can deploy to a length of 60 feet. planned to
The new blanket was to be connected to the station’s electrical grid during orbital darkness when no power was being generated.
About half the size of the original array, the IROSA blanket is more efficient, ultimately producing an additional 120 kilowatts of power. They are designed to attach to brackets at the base of existing wings and extend outward at a 10 degree angle to minimize shadow casting on the array below.
“The first two arrays are performing very well,” said Matt Pickle, senior manager of development projects at Boeing, in a NASA release. “Solar cells are much more powerful than previous generations.”
When all 6 rollout arrays are installed, the overall power generation increases by 20-30% and is almost the same output as the original array when new.
Of the six IROSAs currently under contract, the final two are scheduled to launch next year. It remains to be seen if NASA will purchase two final he IROSAs to reinforce all eight of the station’s original blankets.