Think they had a fair bit of work on composite structures, so perhaps not so strange.
February 2018:
“Orbital ATK has successfully completed the production of the 5,000th composite part for Lockheed Martin’s F-35 Lightning II joint strike fighter aircraft.....
The company currently produces approximately 90% of the upper and lower wing skins, engine nacelles, access covers, and fixed skins for the F-35 aircraft at its Aerospace Structures Division facility in Clearfield, Utah, US.”.......