NASA's crawler-transporters continue to be critical elements for future launch operations; however modifications are required in order to transport a rocket and launch tower combination heavier than the Saturn V moon rockets the crawlers were designed for.

Built in 1965, NASA’s crawler-transporters have carried rockets and spacecraft to the Kennedy Space Center launch pad for more than 40 years. The crawler-transporters will continue to be critical elements for future launch operations; however modifications are required in order to transport a rocket and launch tower combination heavier than the Saturn V moon rockets the crawlers were designed for. Replacing the existing bearings with redesigned traction roller assemblies (TRA) will enable the CT2 to carry the greater loads anticipated with the Space Launch System (SLS). Installing the redesigned traction roller assemblies in the crawler tracks required a significant amount of force in order to remove and install the new the bearings.