Manufacturing Engineer, Propellant

Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus, ownership, and excellence are decisive advantages - and we’re building a world-class team to turn bold ideas into real capability.

This is a rare opportunity to join at an early stage, where you’ll have significant ownership, collaborate with exceptional teammates, and make a direct, measurable impact on our mission and the future of the company - regardless of your function.

We are seeking a Propellant Manufacturing Engineer to lead and execute propellant manufacturing processes for solid rocket motors (SRM) supporting Castelion’s hypersonic strike programs, including Blackbeard. This role focuses on the development, optimization, qualification, and scaling of propellant formulation, mixing, casting, curing, and related processes. You will work hands‑on with energetic materials in a high‑consequence environment, driving process reliability, yield, safety, and throughput as we transition from prototype and research builds to high‑rate production.

Partnering closely with Propulsion Design, Manufacturing, Quality, Automation & Controls, and Test teams, you will ensure propellant processes meet stringent performance, safety, and producibility requirements.

• Own or lead propellant manufacturing processes, including ingredient preparation, batch mixing, vacuum casting, grain forming, curing, and finishing operations.
• Develop, document, and continuously improve process parameters, work instructions, and control plans for propellant production.
• Execute Design for Manufacturability (DFM) and process FMEA activities; drive statistical process control (SPC) and yield improvement initiatives.
• Support new product introduction (NPI) by translating propellant formulation and grain design requirements into robust, scalable manufacturing processes.
• Perform root‑cause analysis and implement corrective/preventive actions for process deviations, defects, or quality issues. Collaborate with Automation & Controls teams to introduce or improve mixing, casting, and handling automation while maintaining strict safety and process control.
• Ensure full compliance with energetic materials handling protocols, DoD 4145.26-M, ATF regulations, ITAR, and site‑specific explosive safety standards.
• Support equipment selection, qualification, maintenance, and process validation for mixers, casting systems, ovens, and related tooling.
• Interface with suppliers on propellant ingredients and intermediate materials; contribute to incoming quality and supplier process improvements.
• Mentor junior engineers and technicians; contribute to training programs and process standardization across production sites.
• Support facility ramp and capability expansion at the Midland, TX operations and Project Ranger campus in New Mexico.

• Bachelor’s or Master’s degree in Chemical Engineering, Materials Science, Manufacturing Engineering, Mechanical Engineering, or related technical field.
• 5+ years of manufacturing or process engineering experience, with at least 3+ years hands‑on work involving solid propellants, energetic materials, or analogous high‑hazard chemical/process manufacturing.
• Demonstrated experience developing or scaling mixing, casting, or similar batch/process operations in a regulated environment.
• Hands‑on experience with propellant or energetic mixing (planetary, vertical, or similar mixers), vacuum casting, and curing processes.
• Strong understanding of propellant rheology, ingredient interactions, process sensitivity, and quality attributes (density, voids, mechanical properties, ballistic…