The Space Launch System's Full-Size Core Stage Mock-up Arrives in Louisiana...

NASA / MSFC / MAF / Steven Seipel

SLS Core Stage Pathfinder Arrives At NASA Michoud (News Release)

The Space Launch System (SLS) core stage pathfinder, which is similar in size, shape and weight to the 212-foot-tall core stage, arrived at NASA’s Michoud Assembly Facility early in the morning on September 27, 2017. To reduce the risk of first-time operations with one-of-a-kind spaceflight hardware for SLS, the agency built a core stage pathfinder.

Like SLS, the core stage pathfinder will be doing something that's never been done -- testing new shipping and handling equipment and procedures from the manufacturing site to the test site to the launch site.

Source: NASA.Gov