The Department of Defense, specifically the United States Air Force (USAF), is seeking information through a Sources Sought notice to support a potential modernization contract for the development, production, fielding, installation, and integration of a Very Low Frequency (VLF) receiver system. The objective is to create a form fit replacement for the legacy Common VLF Receiver Increment 1 (CVRi1) system, utilizing a Modular Open Systems Approach (MOSA) and ensuring compliance with Open Mission Systems (OMS) Tier 2 standards, while integrating a modernized cryptographic device. This VLF receiver system is crucial for all USAF airborne and ground-based strategic platforms, as well as US Navy airborne strategic platforms, enhancing their operational capabilities. Interested parties are encouraged to provide feedback on the draft System Requirements Document (SRD) and should contact Kara Feeney at kara.feeney@us.af.mil or Traci Renzella Molis at traci.renzella-molis.1@us.af.mil for further information. A draft Request for Proposal (RFP) is anticipated in the second quarter of FY25, with an official RFP to follow shortly thereafter, alongside an Industry Day planned for early 2QFY25.