In order to install and unfold a new roll-out solar array just brought by a SpaceX cargo ship, NASA astronauts Josh Cassada and Frank Rubio will don their spacesuits on Saturday and leave the International Space Station.
The spacewalk is set to start about 7:25 a.m. EST (12:25 GMT) on Saturday for Cassada and Rubio, who are both making their first trips into space. When the astronauts turn their spacesuits to battery power, the excursion will formally begin.
The Quest airlock of the space station will be where the astronauts will transfer to the starboard, or right, side of the lab’s solar power truss, where the station’s robotic arm earlier this week installed two new ISS Roll-Out Solar Array, or iROSA, units after removing them from the trunk of a SpaceX Dragon cargo capsule.
The solar arrays, together with many tonnes of supplies and experiments, were carried to the space station by the Dragon spacecraft on November 27.On the excursion on Saturday, Cassada will be referred to as EV-1, or the lead spacewalker. He’ll dress in a red-striped suit. Rubio will be dressed entirely in white.
The space station’s power truss, which is more than a football field long from end to end, has a mounting bracket that will hold the new solar array blankets, which are rolled up around spools and will unfold like a yoga mat once they are mounted.
By loosening bolts and launch constraints, the astronauts will attempt to separate one of the two newly delivered iROSA modules from its container first. Cassada will situate himself on a foot restraint on the robotic arm’s Canadian-built end and grip the solar array spools as the arm transports him to the S4 truss.
The iROSA unit will be mounted on a mounting bracket that was already in place during a previous spacewalk by the two spacewalkers. The iROSA unit will be opened on its hinge, and after that, bolts will be put in place to secure it.
To connect the new iROSA unit to the electrical system of the space station, Cassada and Rubio will match electrical connectors. To connect the original S4 solar panel and the newly installed roll-out solar array to the lab’s electrical grid, a Y cable will be installed.
The attachment bracket connects the new arrays to the station’s power conduits and rotary joints, which keep the station’s solar wings aimed at the sun while it orbits the planet at a speed of more than 17,000 miles per hour.
Eight power channels on the International Space Station are fed by electrical energy produced by one solar array wing that extends from the station’s truss backbone. The new solar array, which will be installed on Saturday, will supply power for the 3A power channel of the space station.
From 2000 until 2009, the original solar panels were carried into space on four shuttle missions. The station’s initial solar arrays’ efficiency has decreased with time, as was to be expected. The new roll-out solar arrays, which will partially cover six of the station’s eight original solar panels, are being installed by NASA to upgrade the power system of the space station.
The power system will be able to provide 215 kilowatts of electricity to support at least another ten years of science operations when all six iROSA units are installed on the station. The upgrade will allow for new commercial modules that are slated to be sent to the space station.
The first pair of new roll-out solar arrays were put over the space station’s oldest set of original solar panels on the P6 truss section, which is situated on the far left end of the power truss. They were flown to the space station last year. Next year, two more iROSA devices will be launched on a SpaceX resupply mission.
Boeing, Redwire, and a group of subcontractors gave NASA the new solar panels.
The roll-out solar array’s clamps were released by the astronauts after the new iROSA unit was mechanically and electrically integrated into the station’s S4 truss. They will use the strain energy in the composite booms supporting the solar blanket to slowly unfold the blankets. The deployment mechanism’s construction does not require motors to operate the solar array.
For storage during launch, the carbon fibre support booms were rolled back against their natural curvature.The solar array will unfold to its fully expanded shape, measuring roughly 63 feet long and 20 feet broad, in 6 to 10 minutes (19-by-6 meters).
That equates to almost half the width and length of the station’s present solar arrays. The new arrays produce roughly the same amount of electricity as the station’s current solar panels, despite their lower size.
The astronauts will tweak tensioning bolts to hold the iROSA blanket in place after the blanket has been spread out.On the truss of the space station, the astronauts will return inward to prepare another iROSA unit, which will be mounted on the left-side P4 truss section during a spacewalk anticipated for December 19.
a spacewalk Saturday will mark the 256th spacewalk since 1998 in support of the construction and upkeep of the International Space Station and the second spacewalk in the careers of Cassada and Rubio.