Senior Mechanical Design Engineer (Structures & Thermal Protection Integration)

STEM Boomerang; Rio Rancho (NM); On-site; USD 120,000 - 180,000; Full time

Benefits offered by this job

Employee equity

4 weeks paid time off

100% employee health coverage

Dental & Vision 90%

FSA/HSA options

401k retirement plan

Paid parental leave

Meals & catering

Snacks & beverages

Fitness stipend

EV charging onsite

Job summary

Castelion in Rio Rancho, NM, seeks a Senior Mechanical Design Engineer to deliver flight vehicle structures for hypersonic strike vehicles, focusing on structural TPS interfaces and high-temperature components. You will work with multidisciplinary teams to design, analyze, build, and validate hardware in a fast-paced environment.

Candidates have a strong background in high-temperature materials, TPS-adjacent structures, and experience with CAD/analysis tools like NX, SolidWorks and ANSYS;

Qualifications

• Bachelor's, Master's, or PhD in Mechanical Engineering or related field.
• 5+ years of experience in structural design and analysis for aerospace or high-performance systems.
• Strong background in high-temperature structures and materials, particularly TPS-adjacent or aerothermal environments.
• Experience designing separation systems, joints, and structural interfaces for flight hardware.
• Proficiency in CAD and analysis tools (e.g., NX, SolidWorks, ANSYS, or equivalent).
• Experience with structural and thermal analysis, including thermal-structural coupling and tolerance stack-up.
• Familiarity with materials used in high-temperature environments (ceramics, carbon-carbon, refractory metals, or similar).
• 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.

Responsibilities

• Design and deliver critical flight vehicle structures interfacing with the thermal protection system (TPS).
• Focus on structural systems that enable TPS integration and high-temperature performance.
• Collaborate with multidisciplinary teams to design, analyze, build, and validate flight-critical structures.

Skills

Structural design

Aerospace experience

High-temperature structures

Thermal-structural analysis

Tolerance stack-up

Problem solving

Education

Bachelor's/Master's/PhD in Mechanical Engineering or related field

Tools

NX

SolidWorks

ANSYS

Job description

Senior Mechanical Design Engineer (Structures & Thermal Protection Integration)

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 (Structures & Thermal Protection Integration)

We are seeking a Senior Mechanical Design Engineer to design and deliver critical flight vehicle structures for Castelion's long-range hypersonic strike vehicles. This role is focused on structural systems that interface with and enable the thermal protection system (TPS), including separating nose tip architectures and other high-temperature structural components. You will work hands-on with multidisciplinary engineering teams to design, analyze, build, and validate flight-critical structures 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 structural design and analysis for aerospace or high-performance systems
  
• Strong background in high-temperature structures and materials, particularly in TPS-adjacent or aerothermal environments
  
• Experience designing separation systems, joints, and structural interfaces for flight hardware
  
• Proficiency in CAD and analysis tools (e.g., NX, SolidWorks, ANSYS, or equivalent)
  
• Experience with structural and thermal analysis, including thermal-structural coupling and tolerance stack-up
  
• Familiarity with materials used in high-temperature environments (e.g., ceramics, carbon-carbon, refractory metals, or similar)
  
• 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