Senior GNC Engineer

About Castelion

Castelion is bringing a new approach to defense development and production: one that focuses on short, iterative design cycles, rapid testing in development, and modern commercial manufacturing strategies for production at scale. Were designing, building, and testing next-generation long-range strike weapons systems to give America and its Allies a definitive edge and deter future conflicts.

GNC Engineer

As a GNC Engineer at Castelion, you will be at the forefront of developing and refining the control systems that guide and control our advanced missile systems. You will be responsible for controlled flight of development vehicles, focusing on aerodynamically efficient flight paths. This position offers the opportunity to work on cutting‑edge technology, creating advanced flight control algorithms while validating simulation models through real‑world testing. You will collaborate closely with cross‑functional engineering teams to deliver accurate flight predictions, drive hardware specification, and conduct successful flight tests.

Responsibilities

• 6 DOF Simulations: Build, maintain and run multi-DOF simulations for multi-stage vehicle flights. Implement the simulation models in Software in the Loop (SITL) systems and transition them to hardware environments. Build a validation workflow for each controller release and integrate with Hardware in the Loop (HITL) systems to test real‑world expected performance.
• Aerodynamic Analysis: Estimate, generate, and calibrate aerodynamic tables and responses. Test and validate aerodynamic performance through flight tests, novel testing, and analytical CFD or Missile DATCOM.
• Electromechanical Actuators: Develop and characterize actuator simulation models based on test data. Specify performance requirements for sensors and mechanisms from a bottom‑up approach. Quantify the impact of sensor and mechanism errors on overall performance.

Outcomes

• Roll‑Pitch Controlled Single Stage Flights: Design and implement initial control systems to achieve roll‑stabilized pitch controlled ballistic paths. Capture flight data to validate simulations and predict aerodynamic performance.
• Roll‑Pitch Flight Path on Multi‑Stage Vehicles: Expand controllers to multi‑stage vehicle while ensuring stable and safe flight envelopes throughout all flight regimes.
• Simulations and Model Predictions: Build and utilize simulations to inform design trades. Specify bandwidth, slew rate, limits, and output sensor requirements for navigation and control.

Basic Qualifications

• Bachelors or Masters degree in Aerospace Engineering, Mechanical Engineering, Electrical Engineering, or a related field.
• 2+ years of experience in GNC engineering or a similar role in the aerospace, defense, or missile systems industry.
• Experience with 6 DOF simulation tools and building flight models for missile systems.
• Familiarity with CFD, Missile Datcom, and other aerodynamics simulation tools.
• Proficient in implementing and testing Software in the Loop (SITL) systems.
• Strong programming skills in MATLAB, Python, C++, or similar languages.

Preferred Skills and Experience

• Experience with Hardware in the Loop (HITL) systems.
• Familiarity with Kalman filters for state estimation and advanced control techniques.
• Strong understanding of aerodynamics, flight dynamics, and control theory.
• Hands‑on experience with electromechanical actuator characterization and building actuator simulation models.

Leadership Qualities

• Bias to Action and Creative Problem Solving. Demonstrated ability to question assumptions and propose breakthrough ideas that lead to successful implementation. Capable of bringing in processes, materials, or concepts from other industries to achieve efficiency gains.
• High Commitment, High Initiative. A genuine passion for Castelion's mission and a strong sense of accountability. Consistently seeks ways to contribute to technical goals and resolve blockers in the development process.
• Clear Communicator. Proactively communicates blockers. Trusted in previous roles to be voice of company with regulators, suppliers gate keepers and customers. Capable of tactfully managing relationships with stakeholders to achieve company‑desired outcomes without compromising relationships. Emails, IMs and verbal interactions are logical, drive clarity, and detailed enough to eliminate ambiguity.

ITAR Requirements

• To conform to U.S. Government export regulations, the applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.

Employment with Castelion is governed on the basis of competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status.

All employees are granted long‑term stock incentives as part of their employment at Castelion. All employees receive access to comprehensive medical, vision, and dental insurance, and the company offers four weeks of paid time off per year.