Author Topic: ISS advanced solar array upgrades (iROSA)  (Read 48052 times)

Offline jbenton

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #40 on: 05/16/2021 12:04 am »
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.


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'm not sure if you're still looking, but I was able to find something. When CRS-11 sent the one-winglet prototype to the station in 2017, NASA released this press release:
https://www.nasa.gov/sites/default/files/atoms/files/spacex_crs-11_mission_overview.pdf

It says that the ROSA payload was 325 kg, so I'm guessing iROSA is slightly more than 650 kg?

This article seems to say that a ROSA should have 66% - 75% less mass than a previous-generation system of the same size:
https://web.archive.org/web/20180306022835/https://www.highbeam.com/doc/1G1-485987901.html

This article from before one was built - when it was proposed as part of Mega-ROSA - says that it was to have a power density of >200 - 400 W/kg at its Beginning of Life.

Offline SWGlassPit

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #41 on: 05/18/2021 02:47 pm »
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.

I don't know about the yellow, but the blue and purple items look to me like EVA bolts.  Yellow may just be an alignment pin.

Offline Jansen

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #42 on: 05/20/2021 06:09 pm »
NASA TV will cover IROSA installation

June 16, Wednesday
6:30 a.m. – Coverage of International Space Station Expedition 65 U.S. spacewalk # 74 to install the first IROSA solar array on the P6 Truss for the 2B Channel Power System; spacewalk scheduled to begin at 8 a.m. EDT and will last 6 ½ hours with Pesquet and Kimbrough (All Channels)

June 20, Sunday
6:30 a.m. – Coverage of International Space Station Expedition 65 U.S. spacewalk # 75 to install the second IROSA solar array on the P6 Truss for the 4B Channel Power System; spacewalk scheduled to begin at 8 a.m. EDT and will last 6 ½ hours with Pesquet and Kimbrough (All Channels)

Offline Jansen

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #43 on: 05/27/2021 04:52 am »
Crossposted:
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.

Offline Jansen

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #44 on: 05/28/2021 01:49 pm »
Mass of iROSA confirmed as 3,042 pounds / 1,380 kilograms

Offline ncb1397

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #45 on: 05/28/2021 02:19 pm »
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.

« Last Edit: 05/28/2021 02:26 pm by ncb1397 »

Offline TrevorMonty

Re: ISS advanced solar array upgrades (iROSA)
« Reply #46 on: 05/28/2021 05:03 pm »
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.
Made In Space Archinaut technology should reduce wing mass considerably. They 3d print boom and power bus in space, still use same solar blankets as ROSA.

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Offline Robotbeat

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #47 on: 05/28/2021 05:54 pm »
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.
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.
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Offline ncb1397

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #48 on: 05/28/2021 06:34 pm »
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.
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.

I expect what is included in each calculation is different between the two numbers. Expecting a 300 KW system to only mass 3 t and fly on Vega is probably a stretch.

edit: looking at the photo, there is a lot more than just the arrays. You have the grapple fixture attached to a long tube which attaches to the support structure for the two solar array assemblies. All of that is likely included in the dragon unpressurized cargo mass figure. Why the solar arrays are suspended rather than on top of the beams that attach to the inside of the trunk likely has to do with where the trunk can hold payloads or extraction considerations.
« Last Edit: 05/28/2021 07:28 pm by ncb1397 »

Offline wjbarnett

Re: ISS advanced solar array upgrades (iROSA)
« Reply #49 on: 05/28/2021 07:35 pm »
The 1380kg mass likely includes the flight support stricture(s) used to keep the array secure within Dragon and allow the CanadaArm2 to remove and relocate them to station. So that mass figure is NOT a good figure of merit, imho.
Jack

Offline Rondaz

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #50 on: 06/04/2021 01:11 pm »
That Dragon trunk is full of power! Once those iROSA solar panels are installed on the @Space_Station, they will roll out like a giant yoga mat. A supercharged yoga mat that provides an increase in energy available for research and station activities.

https://twitter.com/ISS_Research/status/1400508986718294020
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Offline Rondaz

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #51 on: 06/04/2021 01:13 pm »
SpaceX CRS-22: Dragon Spacecraft Separation


Offline SMS

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Offline Bob Shaw

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #53 on: 06/15/2021 10:05 pm »
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?

Offline russianhalo117

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #54 on: 06/15/2021 10:12 pm »
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?

Only cable demating and mating need to be done on the dark side. The rest of the timeline is unconstrained.

Offline SMS

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #55 on: 06/23/2021 06:28 am »
2B (July 20, 2021) -> 4B (July 25, 2021) -> ??

Do we know the later order for future IROSA pairs of batteries in the next Dragon CRS-24 and 25 flights?

2B -> 4B -> 4A?

1A -> 3A -> 3B?

Who knows the schedule order of batteries IROSA assembly and which astronauts are trained to assemble them with the current and future USOS ISS crews?

Thanks for any information on that topic!
« Last Edit: 06/24/2021 05:16 am by SMS »
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Offline Sesquipedalian

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #56 on: 06/25/2021 04:18 am »
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.
« Last Edit: 06/25/2021 04:18 am by Sesquipedalian »

Offline Jim

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #57 on: 06/25/2021 11:52 am »
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.

OBSS was not made for carrying loads.  It does not have an end effector on it.  It is only for personnel movement and access.

Offline Sesquipedalian

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #58 on: 06/25/2021 04:37 pm »
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.
« Last Edit: 06/25/2021 04:38 pm by Sesquipedalian »

Offline SWGlassPit

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Re: ISS advanced solar array upgrades (iROSA)
« Reply #59 on: 06/25/2021 11:39 pm »
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.

I've not seen any analysis on it, but I'd put money on 1100 pounds (solar array plus crew member) being too much mass to swing around on the end of the EIBA.

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