ELLSWORTH AIR FORCE BASE, S.D. - Airman 1st Class Jason Graham, 28th Aircraft Maintenance Squadron electrician, provides ground support while an auxiliary power unit of a B-1B Lancer runs, June 30. The auxiliary power units on a B-1B Lancer allow a quick startup so the bomber can get off the runway quickly. (U.S. Air Force Photo/Airman 1st Class Corey Hook)