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.
Will the new solar panels be in addition to the existing ones? (if so where will they be located)Or replace some of them? (if so, how will the existing ones be disposed of)
Quote from: Sesquipedalian on 07/26/2020 12:11 amI'll ask the obvious question... why are there six and not eight ROSAs?Because the new arrays are far more efficient, only 6 are required to provide sufficient power well into the future.
Do we know why the mid strut appears to telescope?I'm guessing that1. If the tolerances were too tight that they would have difficulty assembling it and needed "slack" in the assembly. The EVA steps have them engaging all the push in place pins (PIP) first before tightening the collars2. The long lower struts are bolted (as apposed to telescoping as well as the loads are greater radially and less from side to side + they needed a fixed triangle (lower strut, mast tower and the upper triangle) to get the geometry correct.
A look at how the iROSAs will be delivered to the ISS - on a pallet that will be removed from the Dragon Trunk, and placed on the POA.
HTV-9 EP will need to jettisoned prior to the EVA's.
HTV-9 EP.HTV-9=H-2 Transfer Vehicle-9 which is the Japan ISS transfer vehicleEP=Exposed Pallet?
So, plenty of info is available for the subscale ROSA array demo on ISS.But for the life of me, I can't find a scrap of info on the actual mass of the ROSA *upgrades* for the ISS's arrays.I can find a bunch of hyper-optimistic figures from early SBIR work done by DSS for ROSA, but no actual final mass figures for these 25kW ROSA array sections. Anyone know how many kilograms each of them are?The lack of information is frustrating compared to the wealth of info on the old arrays.
NASA and Boeing workers lift solar arrays into flight support equipment on April 2, 2021, in the Space Station Processing Facility at NASA’s Kennedy Space Center in Florida. The 63- by- 20-foot solar arrays will launch to the International Space Station later this year.They are the first two of six new solar arrays that in total will 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 215 kilowatts of energy, a 20 to 30 percent increase in power, helping maximize the space station’s capabilities for years to come. The arrays will produce electricity to sustain the station’s systems and equipment, plus augment the electricity available to continue a wide variety of public and private experiments and research in the microgravity environment of low-Earth orbit.Most of the station systems, including its batteries, scientific equipment racks, and communications equipment have been upgraded since humans began a continuous presence on the orbiting laboratory in November 2000. For more than two decades, astronauts have lived and worked on this unique orbiting lab, supporting scientific research that has led to numerous discoveries that benefit people on Earth and prepare for future Artemis missions to the Moon and beyond. Photo Credit: NASA/Frank Michaux
Re-posting this in this thread. I looked at all the documents so far, and none listed mass of the iROSA arrays.Why is this so hard to find?? This is a key piece of information for architectural trade studies. I swear to Goddard, Boeing, if you're insisting on keeping this "proprietary," I hope SpaceX beats SLS core to space with Starship.Quote from: Robotbeat on 03/18/2021 03:44 pmSo, plenty of info is available for the subscale ROSA array demo on ISS.But for the life of me, I can't find a scrap of info on the actual mass of the ROSA *upgrades* for the ISS's arrays.I can find a bunch of hyper-optimistic figures from early SBIR work done by DSS for ROSA, but no actual final mass figures for these 25kW ROSA array sections. Anyone know how many kilograms each of them are?The lack of information is frustrating compared to the wealth of info on the old arrays.
I've also highlighted the locking pins that secure the 2 halves together. I'm assuming that they are driven electromagnetically after the 2 sides are mated.
Quote from: Jansen on 05/24/2021 10:45 pmQuote from: Robotbeat on 05/24/2021 09:38 pm Well, what IS the mass of iROSA?Can’t find the information anywhere! Very different from the original ISS solar arrays which have public mass figures.Each SAW is 2400 pounds. The iROSAs will shadow 2/3s of the SAWs, but are 20% lighter.So ~1280 pounds each, or around 2560 pounds (1161.2kg) for both iROSAs.NASA should be releasing more concrete figures this week.During the media briefing today, the total iROSA payload was stated to weigh 3000 pounds, at around the 22 minute mark.
Quote from: Robotbeat on 05/24/2021 09:38 pm Well, what IS the mass of iROSA?Can’t find the information anywhere! Very different from the original ISS solar arrays which have public mass figures.Each SAW is 2400 pounds. The iROSAs will shadow 2/3s of the SAWs, but are 20% lighter.So ~1280 pounds each, or around 2560 pounds (1161.2kg) for both iROSAs.NASA should be releasing more concrete figures this week.
Well, what IS the mass of iROSA?Can’t find the information anywhere! Very different from the original ISS solar arrays which have public mass figures.
So, 690 kg per 20 KW wing. So 300 KW would be on the order of 10 t. Looks like NASA/Boeing/DSS has the required technology in place and nearly flight qualified to build the Deep Space Transport.
Quote from: ncb1397 on 05/28/2021 02:19 pmSo, 690 kg per 20 KW wing. So 300 KW would be on the order of 10 t. Looks like NASA/Boeing/DSS has the required technology in place and nearly flight qualified to build the Deep Space Transport.29W/kg is pretty crappy compared to UltraFlex at 100-150W/kg or similar figures given for ROSA earlier.I have a feeling they’re not optimizing for mass THAT hard. But it’s disappointing.
Am I right in assuming that as much of the installation as possible will be done during orbital darkness, or at least with the new and old arrays in shadow?
Did they consider using an astronaut mounted on the OBSS to carry the iROSA out to its destination? From my armchair perspective it seems like that would be faster and simpler than passing it back and forth down the truss. And this is exactly the sort of reason that OBSS was left on the station in the first place.
It has something like an APFR where an astronaut can stand, doesn't it? So the OBSS (or technically the Enhanced ISS Boom Assembly) could hold the APFR, the APFR could hold the astronaut, and the astronaut could hold the iROSA.That said, if the loads are indeed too much for the OBSS/EIBA, then that's a deal-breaker.
.....Dragon launched June 3 on a SpaceX Falcon 9 rocket from Launch Complex 39A at Kennedy, arriving at the station a little less than 16 hours later. The spacecraft delivered more than 7,300 pounds of research investigations, crew supplies, and vehicle hardware to the orbiting outpost. Dragon’s external cargo “trunk” carried six new ISS Roll-Out Solar Arrays (iROSAs),.......
Prevent me from going mad. The NASA update I had this morning stated that Dragon had carried all 6 iROSAs !Quote.....Dragon launched June 3 on a SpaceX Falcon 9 rocket from Launch Complex 39A at Kennedy, arriving at the station a little less than 16 hours later. The spacecraft delivered more than 7,300 pounds of research investigations, crew supplies, and vehicle hardware to the orbiting outpost. Dragon’s external cargo “trunk” carried six new ISS Roll-Out Solar Arrays (iROSAs),.......This is wrong - there are just 2 going up this time........?
On which cargo ship the next iRosa panel supports are to be shipped ?
The iROSAs for the 1A and 1B power channels are scheduled to be launched in the trunk of SpX-28 on June 3rd with 1A being installed on June 9th and 1B being installed on June 15thThis is the first time I'm hearing there will be iROSAs for the 2A and 3B power channelshttps://www.nasa.gov/press-release/nasa-to-provide-briefing-coverage-of-spacewalks-for-station-upgrades
Why not make last two arrays transformational
Quote from: Chinakpradhan on 05/30/2023 01:46 amWhy not make last two arrays transformationalAs that would require a new design to be certified for flight, NASA had signed a contract with Boeing for 6 iROSAs that included an option for an additional two. Certifying a new design is more expensive and take more time so NASA went with the option to order two additional iROSAs as it meets their power requirements for the ISS
Quote from: Josh_from_Canada on 05/30/2023 02:20 amQuote from: Chinakpradhan on 05/30/2023 01:46 amWhy not make last two arrays transformationalAs that would require a new design to be certified for flight, NASA had signed a contract with Boeing for 6 iROSAs that included an option for an additional two. Certifying a new design is more expensive and take more time so NASA went with the option to order two additional iROSAs as it meets their power requirements for the ISSPlus ground spares.