【A&D Tech Spotlight】What is MOSA? The Modular Open Systems Approach Revolutionizing A&D

Sonya
6 days ago
6 min read

Without This Technology, Next-Generation Capabilities Are Grounded

Imagine buying a new laptop, only to find it has a proprietary charging port, a proprietary keyboard connector, and a proprietary operating system that only runs the manufacturer's own (and outdated) software. Worse, the RAM and CPU are soldered to the motherboard. To upgrade, you must throw the whole thing out and buy a new one from the same company. For decades, this has been the reality of the defense industry. This "black box," proprietary model led to vendor lock-in, stifled innovation, and resulted in "interminable" upgrade cycles that take 5-10 years.

The Modular Open Systems Approach (MOSA) is the DoD-mandated revolution to end this. It is a design and acquisition strategy that forces all new systems to be built like a modern PC: using common, open, consensus-based interfaces (like USB, PCIe, and ATX). The goal is to "decouple" hardware from software, allowing the government to buy the "best-of-breed" sensor card from Vendor A, a "best-of-breed" AI algorithm from Vendor B, and "plug-and-play" them into a platform from Vendor C. Without this framework, NATO interoperability is a fantasy, JADC2 is impossible, and the rapid acceleration of capability deployment to counter peer adversaries is a pipe dream.

The Core Technology Explained: Principles and Generational Hurdles

Past Bottlenecks: Why Legacy Architectures Failed

Traditional defense acquisition was built on vertically integrated, proprietary architectures. A prime contractor (e.g., Lockheed Martin, BAE Systems) would win a "winner-take-all" contract and build a closed system where all the interfaces were trade secrets. This model had three fatal flaws:

Vendor Lock-In: Once a platform was fielded, the government was held hostage. The original manufacturer was the only one who could perform upgrades or sustainment, leading to non-competitive, monopoly pricing.
Technology Freeze: A fighter's avionics system, designed in 2010, is fielded in 2020 with processors that are hopelessly obsolete. In a proprietary system, swapping that processor is a multi-million dollar "ship-level" re-engineering effort.
Interoperability Disaster: The Army's "black box" C2 system, built by General Dynamics, could not "talk" to the Air Force's "black box" C2 system, built by Raytheon. This mitigates mission success in a joint-force environment.

In an era where threats evolve in months, this "decade-long" upgrade cycle is a critical failure.

What Is the Core Principle?

MOSA is a philosophy of procurement and design centered on open, standard interfaces. It is not a single standard itself, but a set of five core principles mandated by the DoD:

Use Modular Design: Decouple complex systems into independent, replaceable modules.
Employ Open Standards: Base interfaces on consensus-based standards (e.g., from VITA, SOSA, OMS).
Provide Full Design Disclosure: Ensure the government has access to the interface documentation.
Secure Government Purpose Data Rights: The government must own the "digital blueprints" for the interfaces.
Enable Competition: Use this framework to create a competitive market for upgrades.

The entire "system of systems" is built from three main pillars:

The Technical Standard (The "Hardware Socket"): This is the physical and electrical specification. For example, the SOSA (Sensor Open Systems Architecture) Technical Standard, based on the VITA 46/65 (VPX) standard, defines the exact size, pin-outs, and protocols (e.g., PCIe, 100GbE) for ruggedized hardware cards.
The Data Model (The "Software Language"): This ensures the modules can communicate. Standards like the Open Mission Systems (OMS) or Universal C2 Interface (UCI) define a "common dictionary" so a sensor from Vendor A can publish a "Target Track" message that a C2 module from Vendor B can understand.
The Data Rights (The "Business Rule"): This is the legal foundation. The government must secure "Government Purpose Data Rights" (GPDR) for the interfaces. This gives them the legal right to hire a third party (or an ally) to build a new, compatible module, breaking the original vendor's monopoly.

The fundamental goal is to shift competition from the platform level to the module level. A company no longer wins a 40-year sustainment monopoly; it must win by continuously building the best, most cost-effective MOSA-compliant module on the market.

Breakthroughs of the New Generation

Accelerating Capability Deployment: A new EW threat emerges. The DoD can now launch a "rapid acquisition" program for a single SOSA-aligned EW card, test three competing designs, and deploy the winner in months, not years.
Reduced Lifecycle Costs: Open competition for upgrades and sustainment drives down prices. Common modules reduce the inventory and training burden.
Enabling Interoperability (NATO): This is the holy grail. When all allied systems are built on MOSA, a UK-built sensor can be slotted into a US-built vehicle, which then passes data, via a common data model, to a French-built C2 system.
Best-of-Breed Technology: The government is no longer "stuck" with the mediocre processor that the prime contractor chose. It can select the absolute best-in-class module for every single function.

Industry Impact and Applications

The Implementation Blueprint: Challenges from Lab to Field

The MOSA transition is a seismic shift, challenging the decades-old business models of the A&D industry.

Challenge 1: The Hardware Standards War (SOSA / CMOSS)

All services must align on a common set of hardware standards.

Core Components and Technical Requirements:
- SOSA / CMOSS: The U.S. Army is leading with CMOSS (C4ISR/EW Modular Open Suite of Standards), which mandates that all C5ISR equipment in vehicles must use SOSA-aligned, 3U/6U VPX-based "card-and-chassis" systems.
- 3U/6U VPX Modules: This is the physical "Lego block." A new market of specialized "merchant suppliers" (like Curtiss-Wright, Mercury Systems, Kontron) has emerged to build these highly-specialized, rugged, MOSA-compliant cards.

Challenge 2: The Software & Data Standardization (OMS / UCI)

Once the hardware is decoupled, the software must be, too.

Core Tools and Technical Requirements:
- Hardware Abstraction Layer (HAL): A "translator" layer in the software stack. Mission applications (like a fire-control algorithm) are written to the HAL, not to the specific hardware, making them portable.
- Open Mission Systems (OMS): An Air Force-led standard that defines the "common language" for aircraft subsystems. This is critical for the NGAD / CCA (Collaborative Combat Aircraft) program, ensuring the 6th-gen fighter can seamlessly command its AI-driven wingmen, regardless of who builds them.

Challenge 3: The Business & Cultural Revolution

This is the greatest hurdle. MOSA directly attacks the profit-center of the "Prime" contractors: their lucrative, sole-source sustainment and upgrade contracts.

Core Tools and Technical Requirements:
- Data Rights in Contracts (RFP): The Program Manager (PM) is now the most important player. They must have the technical expertise and contractual courage to demand (and get) Government Purpose Data Rights from the Primes.
- Digital Engineering (DE): MOSA is the "what," and Digital Engineering is the "how." In a Digital Twin environment, the government can "virtually integrate" a new MOSA-compliant digital model from a new vendor before buying it, proving interoperability and mitigating mission risk at near-zero cost.

Kingmaker of Capabilities: Where is This Technology Indispensable?

MOSA is now a mandated, non-negotiable requirement for all new DoD programs:

Army Ground Vehicles (CMOSS): All new vehicle-mounted C5ISR systems for EW, C-UAS, and networking are being built on CMOSS.
Air Force (OMS/UCI): The NGAD and CCA programs are "born-digital" and "born-MOSA" to ensure they can be rapidly upgraded with new AI algorithms and sensors.
Navy (Aegis, AN/BYG-1): The Navy was an early MOSA pioneer and has saved billions in upgrade costs on its Aegis combat system and submarine sonar suites by embracing open architectures.
JADC2: The entire JADC2 concept is MOSA. It is the technical and business framework that will (in theory) allow any sensor to connect to any shooter.

The Road Ahead: MOSA-Enabled AI

The primary obstacle to MOSA is cultural inertia. The next wave is MOSA-Enabled AI. By creating a standard hardware and software "platform," MOSA creates an "App Store" for warfare. It allows the DoD to run a "best-of-breed" AI algorithm from a small tech startup (like Palantir) on a ruggedized hardware card (from Mercury Systems) inside a combat system (from Northrop Grumman), enabling "software-defined warfare."

The Investment Angle: Why Selling Shovels in a Gold Rush Pays Off

MOSA is fundamentally reshaping the A&D value chain and, consequently, the investment thesis. The large Prime Contractors (Lockheed, Northrop, Raytheon, GD) face a strategic challenge: they must comply with MOSA, but doing so erodes their high-margin, proprietary sustainment business.

The new "gold rush" is at the component and module level. The winners are the "merchant suppliers" and "pure-play" MOSA specialists. These are the companies that, instead of building the whole "PC," have focused on building the world's best "SOSA-aligned graphics card," "CMOSS-compliant network switch," or "OMS-compliant software."

These companies have immense technical moats (military-grade, rugged, high-speed engineering), and their products are "platform-agnostic"—they sell to all the Primes, for all the programs (Army, Navy, Air Force). Investing in these "Lego block" suppliers, who are providing the foundational hardware for this DoD-mandated, multi-decade modernization cycle, is a direct investment in the "shovels" of this new industrial revolution.

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