GPS Ground Segment Monitor Station Service (MSS) for NGA MSN Obsolescence Mitigation

Section 1: General Information

Pursuant to Revolutionary Federal Acquisition Regulation (FAR) Overhaul (RFO) 15.101(c), this is a Sources Sought Notice/ Request for Information (RFI) only. This notice is issued solely for conducting market research and planning purposes in accordance with RFO Part 10 and RFO Part 5.

This announcement is for Market Research only and does not constitute a commitment, promise, or obligation by the Government to issue a Request for Proposal (RFP), Invitation for Bid (IFB), or solicitation of any kind. The Government will not award a contract based on responses to this notice. The Space Force Portfolio Acquisition Executive (SFPAE) for Satellite Communications and Positioning, Navigation and Timing (SATCOM and PNT) is not seeking proposals at this time and will not accept unsolicited proposals. Respondents are advised that the Government will not pay for any information, bid preparation costs, or administrative expenses incurred in responding to this notice.

Acquisition Attribute

Program Baseline Details

Notice ID / Solicitation Number

SSC-GCS-MSS-SSN-2026

Sponsoring Agency / Office

United States Space Force (USSF) / Space Systems Command (SSC) / MD31

Product Service Code (PSC)

1677 (Space Vehicle Remote Control Systems)

North American Industry Classification (NAICS)

541715 (Research and Development in the Physical, Engineering, and Life Sciences (except Nanotechnology and Biotechnology))

Classification & Security

Controlled Unclassified Information (CUI) / SECRET Facility Clearance Required

Response Date & Time

8 December 2026 at 3:00 PM MST

Primary Points of Contact

Mr. Daniel Hilger, Procuring Contracting Officer (PCO)
Mr. Carl Griffin, Civil Navigation (CNAV) Project Lead

Section 2: System Background & Scope of Work

2.1 Background

The USSF is actively modernizing the GPS Ground Control Segment (GCS) to deliver enhanced Positioning, Navigation, and Timing (PNT) resilience and operationalize modernized civil and military signals. As part of this effort, USSF seeks to address necessary sustainment and modernization of its global PNT ground receiver network.

The legacy ground control segment, the Architecture Evolution Plan (AEP), receives real-time tracking data from a total of 17 global monitor stations, 11 of which are estimated to face obsolescence in late 2028.

USSF seeks options to transition to a modernized, sustainable ground segment architecture to maintain AEP's clock and orbit estimation engine (the Kalman Filter). To that end, the Government is requesting interested respondents submit statements of capability (SOCs) describing potential solutions to provide the capabilities described herein.

Furthermore, the Space Force requires that any replacement ground receiver infrastructure not merely duplicate legacy capabilities but simultaneously address broader enterprise needs. The replacement architecture must serve as the primary operational enabler for:

1. Civil Navigation (CNAV) Modernization: Providing independent, continuous signal-in-space tracking, integrity monitoring, and safety-of-life assurance for advanced civilian signals (L2C, L5, L1C) to support joint Federal Aviation Administration (FAA) and international civil aviation commitments.
2. Military Navigation (MNAV) & M-Code Operations: Integrating secure, high-fidelity tracking of military M-Code signals to enable robust anti-jam, anti-spoof Navigation Warfare (NAVWAR) operations and Regional Military Protection (RMP).

2.2 Spectrum & Signal Tracking Requirements

To demonstrate that the required monitoring capability extends beyond legacy single-frequency L-Band observables, the proposed Monitor Station Service (MSS) must provide simultaneous multi-frequency, multi-code tracking across a growing constellation (up to 63 Space Vehicles). The solution must provide continuous tracking, measurement extraction, and observable processing across the following specific signal tiers:

Signal Tier

Frequency / Signal Type

Capabilities & Processing Requirements

Legacy Signals (Baseline Parity)

L1 (1575.42 MHz):

L1P-codeless

L1 C/A, L1P(Y)
L2 (1227.60 MHz): L2P(Y)

L2P-codless

Continuous tracking, legacy LNAV message demodulation, pseudorange/carrier-phase measurement extraction, and legacy telemetry processing for core AEP Kalman Filter orbit/clock estimation continuity.

Modernized Civil Signals (CNAV)

L5 (1176.45 MHz): Safety-of-Life (SoL), L5I,L5Q
L2 (1227.46 MHz): L2C (L2CM,L2CL)
L1 (1575.42 MHz): L1C (L1CD,L1CP)

CNAV message demodulation, multi-frequency ionospheric delay cancellation, advanced signal quality monitoring (SQM), interference/jamming detection, and civil aviation safety-of-life (SoL) processing standards to support L5 Initial Operational Capability (IOC).

Military Signals (Modernized)

L1 / L2 M-Code (1575.42 MHz / 1227.46 MHz): Earth Coverage & Regional Military Protection (RMP)

Direct M-Code acquisition and tracking, cryptographic channel decoding via NSA-certified security architecture, advanced anti-jam / anti-spoof protections, and Modernized User Equipment (MGUE) warfighter operational support.

2.3 Core Capabilities & Scope of Work

The scope of this market research centers on identifying industry capabilities and realistic timelines to deliver an integrated, secure, and safety-certified Monitor Station Service (MSS) that interfaces seamlessly with AEP and external mission partners (FAA, NGA). The Government intends to acquire and take delivery of the software baseline and associated technical data rights to ensure long-term organic C2 baseline control and sustainment within the Government boundary.

The Government is seeking responses that demonstrate capability across the following core technical tasks:

• Integrated Multi-Signal Ingestion: Acquire, process, format, and distribute raw binary and smoothed pseudorange, carrier phase, Accumulated Delta Range (ADR), and Signal Quality Metrics (SQM) across all legacy, CNAV, and MNAV signals listed in Section 2.2.
• Modular API & Service-Oriented Integration: Expose receiver monitoring and control capabilities through a Modular Open Systems Approach (MOSA) utilizing standardized Application Programming Interfaces (APIs) and messaging layers to decouple data feeds from underlying receiver hardware.
• Safety-of-Life Signal Assurance: Support rigorous software design assurance standards (certifiable up to Design Assurance Level D / DAL D per RTCA DO-278A / DO-178C) to provide real-time signal deformation detection, Code Carrier Coherence (CCC), and anomalous event alerting.
• Cryptographic & Boundary Security: Provide NSA-approved cryptographic handling capabilities for military key management, secure unclassified/classified cross-domain boundary routing, and continuous Risk Management Framework (RMF) security control validation in a secure government cloud/on-prem environment (IL5/IL6) to maintain an active DoD Authority to Operate (ATO).
• Receiver Security Certification (FSET): Provide receiver hardware, software, and firmware capable of achieving or maintaining security certification through the Space Systems Command (SSC) Functional Security Engineering Team (FSET) for deployment across global, unclassified, and collateral Secret monitoring locations, including supporting delta FSET recertification processes for component and cryptographic updates.

Section 3: Information Requested from Industry

To assist the government in conducting its statutory market research, all respondents are requested to organize their capability statements into the following structured sections:

Part A: Corporate Profile

Administrative Details: Company Name, Mailing Address, CAGE code, and Unique Entity ID (UEI).

Socioeconomic Status: State your business size and any applicable socioeconomic designations under NAICS 541715 (e.g., Small Business, 8(a), HUBZone, SDVOSB, WOSB, etc.).

Facility Clearance: Confirm whether your company possesses an active, DOD-approved SECRET Facility Clearance (required for ground segment integration testing and operations).

Existing Government Contract Vehicles: List any existing competitive contract vehicles, such as multiple award indefinite delivery indefinite quantity (MAC IDIQ) contracts, under which your company is currently approved to provide similar scope to that described in this notice.

Part B: Technical capability Questionnaire

Respondents must provide detailed, objective, and verifiable evidence of their capability to execute these requirements. The Government will evaluate vendor capability based on two distinct grading factors:

A. Core Competency Alignment: Direct evidence (e.g., past performance references, specific contracts, and operational program details) demonstrating corporate core competencies that directly translate to GPS ground segment development, real-time receiver data processing, or Kalman filter integration.

B. Technical Component Maturity: Degree of verified proof that the proposed hardware and/or software components currently exist in a mature state (e.g., Technology Readiness Level 6 or higher). Respondents must show that any necessary modifications or delta-developments can realistically be completed within the program timeframes discussed below in Section 3, Part B(i).

Note: Broad technical narratives, marketing descriptions, or unsubstantiated claims of capability without supporting engineering or programmatic evidence will be considered "High Risk."

i. Schedule & Programmatic Feasibility:

The Government is executing a phased acquisition strategy to mitigate receiver network obsolescence while fully modernizing ground monitoring capabilities. The Government desires an incremental capability delivery and operational acceptance plan structured as follows:

• Phase 2.1 (Replace Operational P(Y) Data Feed - Target: Late 2028): Development, testing, fielding, and operational acceptance of the critical subset of Legacy Signals referenced in Section 2.2, necessary to replace legacy signal in space tracking feeds prior to earliest planned obsolescence with zero disruption to the AEP Kalman Filter. This effort includes integration of the solution with the currently operational GPS ground system (AEP) in accordance with ICD-GPS-211, in cooperation with the ground system prime contractor.
• Phase 2.2 (Remaining Core Capabilities - Target: Late 2030): Full development, testing, fielding, and operational acceptance of all remaining core capabilities (including advanced CNAV/MNAV tracking, DO-278A safety assurance, and full NSA cryptographic security certification).  This effort should include scope to integrate the solution with AEP.  A strict interface specification does not currently exist for this capability, but it is desired to limit integration scope imposed on the AEP system.
• Phase 2.3 (Additional Capabilities - Target: CY2032 Desired): Incremental delivery of the lower-priority system preferences defined in Section 3.0, Part D (Additional Capabilities). Note if capacity exists to accelerate development of one or some of these earlier, pursuant to evolving military priority (e.g. multi-Global Navigation Satellite System (mGNSS) monitoring). This additional capability is expected to primarily be compatible with a future GPS ground system not yet developed.  Open interface standards desired.  This scope included for consideration to address transition of the baseline monitoring approach from Phases 2.1-2 from AEP-compliant solution to one compatible with the next-generation system.

Describe your programmatic and engineering strategy to deliver these capabilities incrementally, including a phased, notional Integrated Master Schedule (IMS) mapping your mature components to these specific milestones.

ii. Rapid Duplication & Continuity under an Urgent Operational Need (UON):

Given the operational necessity to modernize ground monitoring capabilities, what is your technical approach to integrate and field an alternative monitor station data stream?  

Specifically address how you will mitigate risks associated with legacy system integration (AEP) and ensure zero loss of mission continuity for the Kalman Filter.

iii. MOSA & Extensible Architecture Design:

How will you design the ground monitoring architecture to be inherently extensible, ensuring it can seamlessly support both CNAV (L5 IOC/Full Operational Capability (FOC)) safety-of-life requirements and expanded constellation tracking (up to 63 SVs) without imposing restrictive assumptions or design constraints on future enterprise-level architectural evolution?

Describe your approach to utilizing a Modular Open Systems Approach (MOSA) to expose receiver monitoring and control capabilities through standardized Application Programming Interfaces (API), effectively decoupling the data services from the underlying receiver hardware.

iv. GPS Multi-Signal Domain Experience Cryptographic Handling & FSET Certification:

Describe your technical approach for acquiring, processing, and distributing raw binary observables, smoothed pseudorange, carrier phase, and Signal Quality Metrics (SQM) for the complete GPS signal suite defined in Section 2.2 Detail your technical expertise and proven methodologies for managing NSA-certified cryptographic functions, secure key loading, and anti-spoof/ anti-jam protections associated with M-Code and P(Y)-code operations.

Describe your familiarity and track record with obtaining and sustaining receiver security certification through the Space Systems Command (SSC) Functional Security Engineering Team (FSET), including navigating delta FSET evaluation cycles for firmware and hardware obsolescence updates.

Describe your company’s capabilities in certifying safety-critical software against RTCA DO-178C/DO-278A standards. Responses should address your approach to meeting various Design Assurance Levels (DALs).

v. Accelerated Test & Evaluation (T&E) and DevSecOps Integration:

Balancing the need for rapid deployment under an urgent operational need with the statutory T&E requirements, describe your methodology for integrating developmental testing, operational assessments, and cybersecurity authorization concurrently to compress the timeline to formal operational acceptance.

Describe your approach to implementing continuous DevSecOps pipeline controls, automated patch testing, and RMF control validation within an IL5/IL6 cloud or hybrid environment to maintain a continuous DoD ATO without disrupting 24/7 space control operations.

vi. Transition and Technical Baseline Assumption:

Considering that the Government is actively managing ongoing technical baseline and interface definitions under exploratory phases, what is your specific methodology for assuming an active, ongoing development effort? How will you validate pre-existing API definitions, data dictionaries, and interface control documents (ICDs) to prevent schedule degradation?

vii. Initial Operational Sustainment & Obsolescence Lifecycle Strategy:

Describe your approach to providing initial operational sustainment, Level 1 operational support/ incident triage, depot-level support, and preventive maintenance inspections (PMIs) across globally distributed remote monitoring sites.

How will you identify, monitor, and mitigate hardware and software Line Replaceable Unit (LRU) component obsolescence (e.g., FPGAs, time servers, network routing equipment) to ensure continuous system availability (> 98%) through at least CY2035?

Part C: Acquisition & Business Strategy

i. Cost & Affordability: Provide a high-level, notional Rough Order of Magnitude (ROM) cost estimate for delivering the Monitor Station Service (MSS) capability across development, integration, and initial fielding, and identify your primary cost drivers.

ii. Delivery Model & Operational Concept:
Describe your proposed delivery model (e.g., software/hardware delivery, managed service, or hybrid) and summarize your operational concept, including nominal day-to-day operations, anomaly alerting, fault recovery, and any data rights constraints. Explicitly detail your technical data rights assertions and confirm your capability to deliver the complete software baseline and interface control definitions to the Government.

iv. Government Furnished Property/ Information (GFE/GFI): What specific Government-furnished information, data, equipment , software, or facility access would your company require from the Government to successfully execute this effort?

v. Contract Type: What contract type(s) (e.g., Firm-Fixed-Price, Cost-Plus-Incentive-Fee, etc.) would you recommend to best incentivize performance and manage risk?

Part D: Additional Capabilities

The capabilities outlined below represent secondary system preferences. As outlined in the Schedule and Programmatic Feasibility section, these capabilities are exempt from the core Objective and Threshold timeline constraints. Respondents should address if and how your approach to meeting core requirements would be impacted to satisfy these secondary requirements.  Options for future system extensibility to incrementally develop/deliver these capabilities are desired.

i. Scalability and Constellation Expansion: Describe the scaling and expansion limits of your proposed receiver architecture. Specifically, detail your system’s capability or planned roadmap to support simultaneous tracking of 64+ Pseudo-Random Noise (PRN) codes across all active GPS frequencies, and how this architecture mitigates signal bottlenecks as the constellation expands.

ii. Technical and Infrastructure Optimization: Detail how your proposed architectural design minimizes physical, cyber, and maintenance overhead at globally deployed, remote unmanned sites. Highlight the utilization of innovative techniques, such as Software-Defined Radio (SDR) technologies, remote signal correlation, data compression, and modernized communications infrastructure, to reduce the footprint and complexity of local physical deployments.

iii. Dual Concept of Operations (CONOPs): Describe extent your solution can support dual operations (C2 from legacy and next-generation control segments) such that they can support sending data at different data rates to each ground segment.

iv. Flexible Signal: Describe extent your solution could support monitoring flexible signal in space waveforms generated by reprogrammable payloads on future planned GPS spacecraft.

v. MOSA-enabled monitoring disaggregation: Ingesting data from other sources (e.g. National Oceanic and Atmospheric Administration’s (NOAA) Continuously Operating Reference Stations (CORS), Jet Propulsion Lab’s (JPL) monitoring network, commercial receiver vendor networks, etc.) and support to potential on-orbit distributed Kalman filters (e.g. autonav) to allow expanded and rapid deployment of new monitoring capabilities.

vi. Coverage: Capacity to economically expand worldwide monitoring coverage (e.g., resolve pacific gap) to ensure good monitoring station distribution across the latitudes and increase the number of monitoring stations in view of each spacecraft. 

vii. Multi-GNSS Monitoring: Describe your solution's ability to monitor multi-GNSS signals (including RNSS constellations), determine signal integrity and derive independent navigation data.

Section 4: Submission Instructions

4.1 Response Guidelines

Technical Approach & Teaming: Submissions should describe the respondent's technical approach and capability to satisfy the integrated scope of work outlined in Section 2. Any proposed teaming arrangements, joint ventures, or partnership structures utilized to meet these requirements must be clearly identified, if applicable.

Page Limit: Submissions must not exceed 15 single-sided pages. The Cover Page, Table of Contents, Acronym List, and notional IMS attachment (if provided as a separate 1-page roadmap/diagram) are excluded from this page limitation.

Formatting Requirements: Text must be in 12-point Times New Roman font, single-spaced, with margins set at 1 inch on the top, bottom, left, and right of each page.

File Format: Responses must be submitted electronically in Adobe PDF format.

Due Date: All responses must be received no later than 8 December 2026 at 3:00 PM MST

Subject Line: All submission emails must use the subject line: RFI Response: SSC-GCS-MSS-SSN-2026 [Company Name].

4.2 Proprietary & Sensitive Information

The government will safeguard any proprietary information or trade secrets identified in responses to this notice in accordance with the Trade Secrets Act (18 U.S.C. 1905). Respondents are solely responsible for clearly marking and identifying any proprietary, restricted, or sensitive data. Please mark the cover page and individual pages containing such information as: PROPRIETARY - CONTAINS BUSINESS SENSITIVE INFORMATION