TU-876 Mk 104

The caption reads (below the dimensions):
"The Mk104 motor was developed for General Dynamics and the US Navy as part of the Aegis shipboard fleet protection system. The Aegis system provides an area air defense capability for ships against high- and low-level aircraft and missile targets. The Mk 104 entered production in 1985."
ATK (formerly Morton-Thiokol) outdoor display in northern Utah, USA. This was a major rocket development facility during the Cold War and beyond.