Manufacturing Engineer, Propellant

STEM Boomerang; Rio Rancho (NM); On-site; USD 110,000 - 170,000; Full time

Benefits offered by this job

Equity

Paid time off

Medical coverage

Dental & Vision

401k

Parental leave

Meals provided

Stipend for wellness

EV charging

Job summary

Castelion in Rio Rancho, NM seeks a Propellant Manufacturing Engineer to lead SRM propellant manufacturing—develop, optimize, qualify, and scale formulation, mixing, casting, and curing. You will work hands-on with energetic materials in a high-consequence setting, ensuring safety, reliability, and producibility as production ramps up.

You’ll collaborate across Propulsion Design, Manufacturing, Quality, Automation & Controls, and Test teams to meet stringent performance and safety requirements

Qualifications

• Bachelor’s or Master’s degree in Chemical, Materials, Manufacturing, Mechanical Engineering, or related field.
• 5+ years of manufacturing or process engineering experience with at least 3+ years hands-on work involving solid propellants or energetic materials.
• Experience developing or scaling mixing, casting, or similar batch operations in a regulated environment.
• Hands-on experience with propellant or energetic mixing, vacuum casting, and curing processes.
• Strong understanding of rheology, ingredient interactions, process sensitivity, and quality attributes (density, voids, mechanical properties, ballistic performance).
• Proficiency with process documentation, PFMEA, and root-cause methodologies.
• Familiarity with equipment design/qualification, instrumentation, and data collection for batch processes.
• Knowledge of energetic materials safety and hazardous location requirements.

Responsibilities

• Lead and execute propellant manufacturing processes for SRMs.
• Develop, optimize, qualify, and scale propellant formulation, mixing, casting and curing.
• Ensure propellant processes meet performance, safety, and producibility requirements.
• Collaborate with Propulsion Design, Manufacturing, Quality, Automation & Controls, and Test teams.
• Drive reliability, yield, safety, and throughput as transitioning to high-rate production.

Skills

Propellant manufacturing

Energetic materials handling

Process optimization

PFMEA & root-cause

Data collection & documentation

Education

Bachelor’s or Master’s degree in engineering

Tools

Minitab

Job description

Rio Rancho, United States | Posted on 08/06/2026

Castelion was founded to restore America’s ability to field advanced weapons at speed and scale. Inspired by the engineering urgency of the WWII and Apollo eras, we combine rapid iteration, vertical integration, and scalable manufacturing to deliver affordable, high-performance strike systems. Our mission: rebuild industrial agility to strengthen national security and outpace evolving threats.

About the Role:

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.

Requirements

Basic Qualifications

• 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 performance).
  
• Proficiency with process documentation, statistical tools (Minitab or similar), PFMEA, and root-cause methodologies.
  
• Familiarity with process equipment design/qualification, instrumentation, and data collection for batch processes.
  
• Working knowledge of energetic materials safety, hazardous location requirements, and large-scale chemical handling practices.
  
• Ability to interpret engineering drawings, specifications, and material data sheets.
  

Preferred Skills and Experience

• Direct experience manufacturing solid rocket motor propellants for DoD, NASA, or commercial space/hypersonic programs.
  
• Background in fast-paced aerospace or defense production environments (startups or primes).
  
• Experience scaling processes from laboratory/prototype to low-rate or high-rate production.
  
• Familiarity with insensitive munitions practices, motor case interfaces, or propellant-to-liner bonding processes.
  
• Prior involvement in facility stand-up, equipment commissioning, or production ramp of energetic materials lines.
  
• Experience with ITAR-controlled programs and classified manufacturing environments.
  
• Employee Equity: Meaningful equity forall full-time employees - share value has increased 150x in three years
  
• Personal Time Off: Four (4) weeks of paidtime off to unplug, reset, and come back sharp—velocity matters,burnout doesn't
  
• Medical: We offer plans at 100% employeecovered and 80% of dependent coverage
  
• Dental & Vision: We cover 90%employees and 80% for dependents to ensure you and your family haveaccess to quality preventive and ongoing care
  
• FSA/HSA: To support long-term health andfinancial resilience, we offer FSA and HSA options that allowemployees to set aside pre-tax dollars for eligible medical anddependent care expenses
  
• Retirement: 401k plan offered to supportlong term financial growth along side high-impact, high-velocity work
  
• Paid Parental Leave: We support growingfamilies with meaningful time to bond and recover. Birthing parentsare eligible for up to 10 weeks of paid leave, while non-birthingparents may take up to 4 weeks of paid leave. This time can be usedfor pre-natal care, pregnancy, childbirth, and related medicalneeds—ensuring every parent has the support they need during thisimportant life moment.8-weeks of paid parental leave for allparents. Additional paid pregnancy leave for CA employees
  
• Meals & Catering: Frequently cateredlunches and team meals, plus company-covered meals when extra timeor effort is required
  
• Snacks & Beverages: Fully stockedkitchen with unlimited snacks and drinks to keep you fueledthroughout the day
  
• Performance & Fitness: $100 monthlyfitness stipend to support peak performance and health, both insideand outside of work
  
• EV Charging: Onsite electric vehiclecharging available for employees