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William Vardaman, mechanical technician with the Jacobs contracting team, performs engine maintenance on NASA's crawler-transporter 2 on March 26, 2019, in the crawler yard located in Kennedy Space Center's Launch Complex 39 area. Recent engine work included rebuilding the vehicles’ fuel pump assemblies and installing new oil pumps that will help minimize future wear. This is one of two crawler-transporters that carried rockets and spacecraft, including the Apollo/Saturn V and space shuttle, from the Vehicle Assembly Building to the launch pad. NASA’s Exploration Ground Systems oversaw modific…