This company is also known as ATK and also see Thiokol. (NYSE = ATK)

-ATK is a booster manufacturer for Delta rockets (Boeing). The GEM variants were solid fuel engines, using propellants such as HTPB.

-GEN-40s were mounted on the Delta 2, grouped around the rocket fuselage. The the GEM-46s were mounted the same way in the later Delta 2 and Delta 3 models.

-In the Delta 4 the most powerful GEM-60s were used. All of them are boosters that are rejected once they have finished up their fuel.

“Delta with various GEM”

-For the Minotaur program they used the Orion-38 solid fuel engine (HTPB) in the 3rd and 4th stage. The Pegasus XL used the Orion-50XL engines in its first and second stages and an Orion-38 in its 3rd stage.

-The Taurus rocket had an Alliant Techsystems Orion-50S engine in its 1st stage, another Orion-50S in its 2nd stage and an Orion-38 in its 3rd stage.

-The Titan 4 had two SRMU engines. Like all of them they were solid fuel boosters that were mounted around the rocket fuselage.