The Naval Sea Systems Command (NAVSEA) is soliciting proposals for the development, integration, testing, production, and installation of the Multifunction Modular Mast (MMM) Payload Sensor system to support UAV command and control for submarines. This posting provides amendments and answers to questions related to the original solicitation. There is no funding associated with this announcement. The solicitation is issued electronically, and interested offerors must monitor official systems for updates and comply with specific procedures to access Government Furnished Information.