They going run out of steel cases so its either make more or shift to more powerful booster based on OmegaA.
Yes there are at least 80 1/2 thick steel cases that are still within flight spec. 80 cases is the exact amount required for 16 boosters or 8 SLS missions.(5 segments per booster, 2 boosters per mission) I've heard rumblings that there are more steel cases, but they dont meet the specs, some are supposedly out of round.
There will be no more steel cases built.
We've got enough SRBs for 8 missions, enough heritage/now adaptation RS25s for 4 missions, with production underway for 6 new build RS25s to be delivered by Sept. 30, 2024.
We need to get to SLS Block 2 as quickly as possible. I'd love to see the dual F-1B Pyrios booster as the advanced booster, but the large diameter solid propellant investment made by NASA in Utah back in the 70's 80's was worth hundreds of millions of dollars, will most likely continue to be utilized via their graphite wound cases.
A 92 inch diameter, 27 foot long Pathfinder article, composite case was produced by ATK in 2013. ATK identified more than 400 changes and improvements, which NASA approved. These changes have reduced assembly time by approximately 46 percent, saving millions of dollars in projected costs for the SLS system.
The OmegA system is taking me some time tio get used to. In essence, its using a partial Shuttle SRB as the core stage with strap on SRBs.
I need to start thinking of it in terms of a Solid Rocket Motor as the core stage, coupled with strap on Solid Rocket Boosters.