Complex sentence: In the late 1950's to mid 1960's Pugsley worked at General Dynamics-Astronautics Sycamore canyon Rocket Test facility as a technical writer writing countdown procedures for Atlas and Centaur Rocket tests.
Split into simpler sentences: In the late 1950's to mid 1960's Pugsley worked at General Dynamics-Astronautics Sycamore Canyon Rocket Test facility as a technical writer. Among other projects, he wrote countdown procedures for Atlas and Centaur Rocket tests.