H-FIXTURE REMOVAL WORKOnce RiTS was installed and its occupants checked into their quarters, Cassidy and Behnken moved onto the second set of tasks, removing “H-fixtures” on the base of two solar arrays — mast canisters — on the port side of the ISS, according to NASA.These were originally used for ground processing of the arrays before they were launched and are no longer needed. In their place is expected to be installed a piece of equipment to hold new solar arrays within the next several years.Called iROSA, or ISS Roll Out Solar Array, these power-generating devices are designed to improve and augment the existing eight arrays, which collectively take up a space larger than an American football field. As they are aging — the oldest pair was launched in 2001 with the other three launched between 2006 and 2009.Each iROSA is expected to be placed in front of the legacy arrays, according to NASA, and be attached via a modification kit installed onto the same mount the H-fixtures are on.While each iROSA will shadow about two-thirds of the legacy arrays, the setup is expected to “increase power performance compared to the legacy ISS solar array.”Ultimately, six iROSA devices will be delivered via three SpaceX Dragon cargo launches starting as early as 2021, according to NASA.Only two H-fixtures were removed during U.S. EVA-68. A total of six need to be removed for all six iROSA modification kits to be installed.One H-fixture was originally scheduled to be removed during the July 1 spacewalk. However, complications prevented its removal and required teams on the ground to re-evaluate their procedures and develop a way to pry them away from the canister.
I'll ask the obvious question... why are there six and not eight ROSAs?
Quote from: Sesquipedalian on 07/26/2020 12:11 amI'll ask the obvious question... why are there six and not eight ROSAs?I would venture a guess that higher efficiency cells make it unnecessary to place more.
Quote from: robertross on 07/26/2020 01:13 amQuote from: Sesquipedalian on 07/26/2020 12:11 amI'll ask the obvious question... why are there six and not eight ROSAs?I would venture a guess that higher efficiency cells make it unnecessary to place more.The NTRS presentation referenced includes the following (page 4): "Upgrading all 8 power channels would provide the most operational flexibility for the program 6 channels is the minimum amount required to avoid negatively impacting ISS operations."I would imagine that if the (6) upgrades go well, that eventually they decide to do all (.
I've trawled the internets and tried to find out if the iROSA arrays are silicon-based, or gallium-arsenide. I've not been able to find out. does anyone know?
IPA project will deliver 6 new external solar array wings in 3 pairs on flights SpX-22, SpX-25, and SpX-26. EVA tasks to configure the target wing locations has already begun, with support structure removal tasks during the most recent 3B battery EVAs. EVA tasks to complete configuration will continue throughout the remainder of 2020.• First delivery of 2 IPA Mod Kits is complete for manifest on NG-14• Installation to the 2B & 4B Mast Canisters is expected on the IROSA Prep EVA post Crew-1 arrival Manufacturing of the first two ISS Roll Out Solar Array (IROSA) wings is in work for SpX-22◦ The current schedule has limited margin Manufacturing of the first composite Deployable Carrier continues to support launch package integration upon arrival of IROSA Wing 1 & 2 in December 2020
Making power moves. A new set of Boeing-built solar arrays will help power @Space_Station to keep cutting-edge orbital research capabilities and commercial opportunities going for years to come.Release: https://boeing.mediaroom.com/news-releases-statements?item=130801
HOUSTON, Jan. 11, 2021 – Boeing [NYSE: BA] will support the International Space Station’s (ISS) growing research capabilities and commercial opportunities with new solar arrays to increase the orbiting laboratory’s power supply. The modification to Boeing’s ISS sustainment contract with NASA calls for Boeing to deliver six additional solar arrays to NASA for installation beginning in 2021.The new 63-foot-by-20-foot (19-meter-by-6-meter) arrays will together produce more than 120 kilowatts of electricity from the sun’s energy, enough to power more than 40 average U.S. homes. Combined with the eight original, larger arrays, this advanced hardware will provide a 20 to 30 percent increase in power, helping to maximize the station’s capabilities for years to come. The arrays will provide ISS with electricity to sustain its systems and equipment, plus augment the electricity available to continue a wide variety of public and private experiments and research in the station’s unique microgravity environment.“When it comes to game-changing research and technological development, the space station is currently hitting its full stride,” said John Mulholland, ISS vice president and program manager for Boeing. “These arrays, along with other recent upgrades to the station’s power system and data-transfer speed, will ensure that ISS remains an incubator and business model in the commercial space ecosystem for the coming decades. Access to this unique lab will continue to pay off as researchers study the challenges of future deep-space exploration and make discoveries that improve life on Earth.”Most of the ISS systems, including its communications systems, batteries and scientific equipment racks, have been upgraded since humans began a continuous presence on the orbiting laboratory in November 2000. Two International Docking Adapters, manufactured by Boeing, have been attached to the ISS to allow commercial spacecraft to dock autonomously to the station. Boeing is the prime contractor for ISS sustainment; the company’s studies have determined that the ISS could safely operate beyond 2030 if NASA and its international partners choose to do so.Deployable Space Systems of Santa Barbara, California, will produce the structure of the new arrays, including the canister and frame that will unfurl to hold the solar-array blankets in place. Deployable Space Systems also built the canister, frame and solar array blanket for a prototype of the new arrays that was successfully tested aboard the ISS in June 2017.Spectrolab, a Boeing company based in Sylmar, California, produces the arrays’ XTJ Prime solar cells, which will be some of the most powerful ever launched into space. They are the same solar cells that power Boeing's CST-100 Starliner spacecraft in flight and while docked to the ISS. Spectrolab also produced the station’s original solar cells, as well as the solar cells tested on the prototype.“The XTJ Prime space solar cells are much more efficient than any of their predecessors and are fit to support the cutting-edge research being done aboard the International Space Station,” said Tony Mueller, president of Spectrolab.For more information on Spectrolab, visit www.spectrolab.com. For more information on Boeing Defense, Space & Security, visit www.boeing.com. Follow us on Twitter at @BoeingSpace.Boeing is the world’s largest aerospace company and leading provider of commercial airplanes, defense, space and security systems, and global services. As the top U.S. exporter, the company supports commercial and government customers in more than 150 countries and leverages the talents of a global supplier base. Building on a legacy of aerospace leadership, Boeing continues to lead in technology and innovation, deliver for its customers and invest in its people and future growth.