The Naval Sea Systems Command plans to award a sole-source modification to General Dynamics Mission Systems to increase Engineering Support Service hours by 42,000 for the Hammerhead Program, a moored-torpedo mine system. This additional support is needed to meet critical program requirements and engineering changes for modified configurations, as GDMS is the only responsible source capable of performing the work without unacceptable delays. Competing the requirement would cause an estimated 24-month delay, halting engineering efforts and preventing the transition to production. No budget amount is specified, and the location for performance is not mentioned. Responses to this notice must be submitted by the stated deadline, but no bid or submission timeline is provided.