The mobile launch tower that will support NASA's next exploration rocket is on its way to launch pad 39B at Kennedy Space Center.
The crawler-transporter hauling the 6.8-million pound launcher -- towering some 400 feet off the ground -- began rolling from a park site next to the Vehicle Assembly Building at 9:15 a.m.
The 4.2-mile trip to the pad will give engineers data on how much the tower sways and wiggles during the journey. Then two weeks of tests at the pad will provide a comprehensive "fit check."
It's only the second time the mobile launcher has been moved. The first time it only moved a few hundred feet, from its construction site west of the assembly building to a parking area on the eastern side.
The Apollo-style mobile launcher was built for the cancelled Constellation program's Ares I rocket. The base and tower structures have cost $238 million to date.
NASA expects to spend roughly $100 million to rebuild the base to support the much heavier Space Launch System, the new heavy-lift rocket planned for human exploration of deep space.
Then the structure will have to be outfitted with the various systems needed to support the rocket and an Orion capsule, at a so far unconfirmed cost.
The mobile launcher is supposed to be completed in time to support an uncrewed 2017 test launch of the new vehicle from pad 39B. Read the full story here.