The Space Shuttle Orbiter Pathfinder (honorary Orbiter Vehicle Designation: OV-098) is a Space Shuttle simulator made of steel and wood.
Originally unnamed, the simulator was built at the Marshall Space Flight Center in 1977 for use in activities such as checking roadway clearances, crane capabilities and fits within structures. It was later shipped by barge to the Kennedy Space Center and was used for ground crew testing in the Vehicle Assembly Building, Orbiter Processing Facility, and Shuttle Landing Facility. Pathfinder is approximately the same size, shape and weight of an actual Orbiter. The use of Pathfinder allowed facilities to be tested without requiring the use of the more delicate and expensive Enterprise.
Pathfinder is noticeably shorter than actual shuttle orbiters. Places where this is most noticeable are where the forward section blends into the wings and where it attaches to the external tank.
After it had sat in storage for many years, a Japanese organization funded the refurbishing of the steel mock-up to more closely resemble an actual Space Shuttle and named it Pathfinder. It was displayed at the "Great Space Shuttle Exposition" in Tokyo from June 1983 to August 1984.
U.S. Space & Rocket Center
Pathfinder has since been returned to the U.S. and is presently on display at the U.S. Space & Rocket Center in Huntsville, Alabama.
It is displayed as part of a complete Shuttle stack which comprises the Pathfinder, the MPTA-ET external tank, which was used for propulsion tests with MPTA-098 , and two prototype Advanced Solid Rocket Booster casings, which were developed after the Challenger accident but never put into production.
In 1999, NASA removed the forward assemblies from each SRB attached to the Pathfinder stack. Although the SRBs are recovered and reused after each flight, several of the forward assemblies had been damaged or lost over the history of the Space Shuttle program necessitating the acquisition of those attached to the Pathfinder stack as spares.
On June 3, 2008 the floor on the starboard side equipment bay section separated from the rest of the orbiter. The structural integrity of Pathfinder was compromised due to years of weather damage; mostly due to a hole in the commander's window. It has since been restored.