It is the same as Aerojet-General Tire & Rubber. It made solid fuel rocket engines for the Atlas V.

--These engines are located in the lower part of the rocket to act as Boosters.

-This missile built by Lockheed Martin, had five attached boosters, from GenCorp Aerojet (name by which it was also known).

-Curiously the engines of the main body were RD-18 twins of Russian design, and they were later constructed by P & W. (see RD Amross).

"Atlas V at launch"