JD Bales, mechanical engineer with the Propulsion, Structures & Manufacturing Enterprise Branch of the Materials and Manufacturing Directorate, lifts a new light bulb into place at Joint Base Langley-Eustis, Virginia, April 30, 2019. The lightbulbs being used are part of the 633d Air Base Wing Arrow Spark program. The light bulbs have not been replaced in more than 10 years. (U.S. Air Force photo by Airman 1st Class Marcus M. Bullock)