Photos: Mobile launch tower heads for pad

One of NASA's heavy-duty diesel-powered crawlers will move the space agency's towering new 39-story mobile launch platform Wednesday to pad 39B at the Kennedy Space Center.

The 4.4-mile trek began around 9:15 a.m. EST (1415 GMT) Wednesday from the mobile launcher's park site north of the Vehicle Assembly Building. The tower is heading for pad 39B to test its dynamics during rollout and check electrical and water connections with the seaside launch complex.

The mobile launch platform is the tallest structure to roll on top of a crawler-transporter since 1975. The tower will be used by NASA's Space Launch System, a heavy-lift rocket for deep space exploration due to debut in late 2017.

Credit: Mike Brown/Spaceflight Now