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.
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.
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.