Ground support technicians check out the treads on crawler-transporter 2 (CT-2) as the vehicle moves slowly along the crawlerway toward the Vehicle Assembly Building at NASA's Kennedy Space Center in Florida. The crawler took a trip to the Pad A/B split to test upgrades recently completed that will allow the giant vehicle to handle the load of the agency's Space Launch System rocket and Orion spacecraft atop the mobile launcher. The Ground Systems Development and Operations Program oversaw upgrades to the 50-year-old CT-2. New generators, gear assemblies, jacking, equalizing and leveling (JEL) hydraulic cylinders, roller bearings and brakes were installed, and other components were upgraded to prepare for Exploration Mission 1.