This is a model of unknown scale of the Harpoon RGM-84A, the first version of a U.S. Navy submarine-launched and ship-launched anti-ship missile. Made by McDonnell Douglas, it had a range in excess of 65 miles and carried a 488 lb conventional warhead. First deployed with the U.S. Navy in 1977, advanced versions are still in service today. John and Cynthia Heyde donated this model to NASM on an unknown date.
This object is on display in James S. McDonnell Space Hangar at the Steven F. Udvar-Hazy Center in Chantilly, VA.