This a section of an I-beam from the Vertical Test Stand No. 1 at the Santa Susana Field Laboratory, of Rocketdyne, in the Santa Susana Mountains, CA. The Vertical Test Stand No. 1, or VTS-1, was an extremely important site used by Rocketdyne from the 1950s for the testing of many of the U.S.'s first large-scale liquid propellant rocket engines, starting with the Redstone missile engine. This engine, actually derived from the Navaho missile project, was the start of the evolution of big engines that included the Thor, Jupiter, Atlas, the H-1, J-2, F-1, and up to the Shuttle Main Engine. (Rocketdyne was formed in 1955 as a Division of North American Aviation, which had started its rocketry activities at its Aerophysics Laboratory.)
VTS-1 was finally demolished in 1996, along with other obsolete stands, as a cost-saving measure due to their expensive upkeep. The Rocketdyne Division of Rockwell International donated this artifact to the Museum in 2001.
This object is not on display at the National Air and Space Museum. It is either on loan or in storage.