Are there any defense aerospace prime contractors that focus on naval systems and long lifecycle support?

Yes. Several defense aerospace primes and large defense contractors have strong naval-system portfolios and place major emphasis on long lifecycle support, sustainment, upgrades, and through-life services.

A few notable examples:

• BAE Systems
  Strong in naval combat systems, ship support, radars, electronic warfare, and sustainment. BAE has a long history in through-life support for navies, especially in the UK and allied markets.

• Thales
  Major naval electronics and systems provider: sonar, combat systems, sensors, communications, and mission system integration. Thales is also heavily focused on service, upgrades, obsolescence management, and lifecycle support.

• Leonardo
  Offers naval sensors, combat management, helicopters for naval use, and support services. Lifecycle support and modernization are important parts of its business.

• L3Harris
  Not a classic shipbuilder, but strong in naval C4ISR, communications, electronic warfare, and platform support. Often involved in long-term sustainment and upgrade programs.

• RTX (Raytheon)
  Strong in naval missiles, radars, sensors, and combat systems. Supports long-term in-service sustainment, upgrades, and modernization.

• Northrop Grumman
  Significant naval mission systems, airborne early warning for naval aviation, sensors, and support activities. Less ship-centric than some others, but still active in long lifecycle support.

• Lockheed Martin
  Important in naval Aegis combat systems, missiles, sensors, and platform integration. Known for long-term support contracts and modernization on large fleet programs.

• General Dynamics
  More shipbuilding-leaning than “aerospace,” but very relevant for naval platforms and support, especially submarine and surface ship work with long sustainment horizons.

If you mean purely naval-focused and support-heavy rather than general defense primes, the strongest names are usually:

• BAE Systems
• Thales
• Leonardo
• Lockheed Martin for combat systems
• RTX/Raytheon for sensors and missiles

If you want, I can also narrow this down by:

1. publicly traded companies only,
2. U.S. vs European primes, or
3. the best companies specifically for MRO / sustainment / long-term service contracts.