I just learned an interesting tidbit. I had never understood how United Technologies had lost the Titan IVB upgraded booster to Hercules, circa 1987.
Hercules had not been part of the Big Solids Craze of the 1960's
-120-inch = UTC
-156-inch = Thiokol & Lockheed
-260-inch = Aerojet
At the time Hercules was merely doing the Minuteman third stage... except they eventually lost it to UTC on Minuteman III. More generally, Minuteman (and Peacekeeper, and SLBM) were fractioned between the solid-fuel contractors. I suppose it was a matter of redundancy and resiliency.
Minuteman I : Thiokol + Aerojet + Hercules
Minuteman II : Thiokol + Aerojet + Hercules
Minuteman III: Thiokol + Aerojet + United Technologies
So how did Hercules "stole" UTC the Titan IVB, booster upgrade: called USRM ?
I came to understand that Hercules had their breakthrough in the big SRB business... via SLC-6 Shuttle Filament Wound Casings. Albeit Thiokol would still provide the solid-fuel inside !
FWCs were already in doubt before Challenger as the hills surrounding SLC-6 might reverberate the Shuttle noise and wreck the lighter casings. Challenger of course killed them for good.
Yet Hercules bounced back and scored their USRM victory. Albeit it was kinda bittersweet for everyone.
Later ATK brought together Hercules and Thiokol https://en.wikipedia.org/wiki/Alliant_Techsystems
Lockheed and UTC solid-fuel businesses had been closed down, and this left ATK as the solid-fuel lobby that still does a lot of damage to NASA and its politics (sigh).
ITTL without Shuttle SRB massive elephant in the room, the solid-fuel-booster business may contract faster. Although ICBM and SLBM won't go away, that big cake.
