Senior Mechanical Design Engineer (RF Systems & Radomes)

STEM Boomerang; Rio Rancho (NM); On-site; USD 130,000 - 180,000; Full time

Benefits offered by this job

Equity for employees

Paid time off (4 weeks)

Medical coverage 100% employee

Dental & Vision coverage 90%

FSA/HSA options

Retirement plan 401k

Parental leave up to 10 weeks

Meals & snacks provided

Fitness stipend $100 monthly

EV charging onsite

Job summary

Castelion in Rio Rancho, NM, seeks a Senior Mechanical Design Engineer specializing in RF systems and radomes. You will design, analyze, build and validate radomes and RF packaging for long-range hypersonic strike vehicles, focusing on structural integrity, thermal survivability, and RF performance.

Collaborate with multidisciplinary teams in a fast-paced hardware-led environment, applying CAD/analysis tools and rigorous testing to deliver robust RF structures that meet extreme environmental

Qualifications

• Bachelor's, Master's, or PhD in Mechanical Engineering or related field.
• 5+ years of mechanical design experience in aerospace or high-performance systems.
• Experience designing radomes, RF-transparent structures, or packaging for RF/antenna systems.
• Familiarity with RF performance considerations and high-temperature materials.

Responsibilities

• Design and deliver RF-critical structures and packaging for RF/antenna systems.
• Develop radomes and RF packaging to ensure RF performance and thermal survivability.
• Collaborate with multidisciplinary teams to validate radomes and packaging in hardware-driven environment.

Skills

RF systems design

Thermal analysis

Structural analysis

CAD tools

Aerospace experience

Tolerance stack-up

Troubleshooting

Education

Bachelor's/Master's/PhD in Mechanical Engineering

Tools

NX

SolidWorks

ANSYS

Job description

Senior Mechanical Design Engineer (RF Systems & Radomes)

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:

Senior Mechanical Design Engineer (RF Systems & Radomes)

We are seeking a Senior Mechanical Design Engineer to design and deliver RF-critical structures and packaging for Castelion's long-range hypersonic strike vehicles. This role is focused on radome development and RF subsystem integration, ensuring structural integrity and thermal survivability while preserving RF performance. You will work hands-on with multidisciplinary engineering teams to design, analyze, build, and validate radomes and RF packaging solutions in a fast-paced, hardware-driven environment.

Requirements

• Bachelor's, Master's, or PhD in Mechanical Engineering or related field
  
• 5+ years of experience in mechanical design for aerospace or high-performance systems
  
• Experience designing radomes, RF-transparent structures, or packaging for RF/antenna systems
  
• Familiarity with RF performance considerations such as dielectric properties, insertion loss, and boresight error
  
• Strong background in structural and thermal analysis for extreme environments
  
• Proficiency in CAD and analysis tools (e.g., NX, SolidWorks, ANSYS, or equivalent)
  
• Experience with tolerance stack-up, alignment, and precision assembly design
  
• Familiarity with materials used in RF applications (e.g., ceramics, composites, low-loss dielectrics) and high-temperature environments
  
• Experience with hardware build, test, and troubleshooting in a lab or flight hardware environment
  
• Strong problem-solving mindset, thriving in a fast-paced, hardware-rich, high flight cadence environment
  
• 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