About the role
Senior Mechanical Design Engineer (RF Systems & Radomes) - Castelion Corporation | Career Page Senior Mechanical Design Engineer (RF Systems & Radomes) Rio Rancho, New Mexico, United States Apply for Position Or refer someone Job Openings Senior Mechanical Design Engineer (RF Systems & Radomes) About the job Senior Mechanical Design Engineer (RF Systems & Radomes) Why Castelion, Why Now Castelion is moving incredibly fast to develop and deliver advanced defense systems at a time when execution matters more than ever. We believe focus and technical excellence are decisive advantages - and we are building a team that can deliver real capability, not just concepts. This is a rare opportunity to join at an early stage, where your work will directly shape critical systems, influence major technical decisions, and have immediate, real-world impact. 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.
Responsibilities Design and develop RF-transparent structures, including radomes, windows, and associated support structures for high-speed flight vehicles Lead the architecture and detailed design of RF subsystem packaging, including mounting, alignment, and environmental protection of antennas, seekers, and electronics Perform structural and thermal analyses to ensure performance and reliability under extreme aerothermal, pressure, and dynamic environments Work closely with RF, avionics, materials, and thermal teams to ensure designs meet RF performance
requirements (e.g., transmission, reflection, boresight error) while maintaining structural integrity Develop and analyze interfaces between radomes, TPS, and primary structure, including sealing, attachment, and thermal isolation strategies Conduct tolerance analysis and assess alignment sensitivity and deformation impacts on RF performance Support prototyping, assembly, and hardware bring-up, including troubleshooting and root cause analysis of structural and RF performance issues Define and execute qualification and environmental test plans, including thermal, vibration, and RF testing Optimize designs for mass, thermal performance, RF transparency, and manufacturability Mentor junior engineers and contribute to best practices in RF structure and packaging design Partner closely with program leadership to make technical trades aligned with mission success Basic
Qualifications 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 Other Duties Please note this job description is not designed to cover or contain a comprehensive listing of activities, duties or
responsibilities that are required of the employee for this job. Duties,
responsibilities and activities may change at any time with or without notice.
Benefits And
Perks All full-time employees are granted meaningful long-term equity, sharing in the company's significant growth trajectory. We offer four (4) weeks of paid time off, ten (10) company-paid holidays, and comprehensive health
benefits - including 100% employee-covered medical and strong dependent coverage, along with dental and vision plans. We also provide paid parental leave to support growing families, a $100 monthly fitness stipend to promote health and performance, and onsite EV charging for convenience. In addition, employees enjoy
perks like catered meals, company-covered food during high-demand periods, and a fully stocked kitchen to stay fueled throughout the day. While this position does not currently require a U.S government-issued security clearance, it may in the near future. Therefore, the ability to obtain and maintain a U.S. government–issued security clearance is required. U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance. Affirmative Action/EEO Statement 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. Apply for Position Or refer someone Share Facebook Line LinkedIn X (Formerly Twitter) Whatsapp Email Powered by Manatal
About Castelion
Castelion is a modern defense production company building long-range hypersonic strike systems to address a critical national security gap. Founded in 2021, Castelion was created in response to the recognized need for the United States to rapidly develop hypersonic capabilities to remain competitive with near-peer adversaries and deter future conflicts.
The company operates under the philosophy of "Peace through Deterrence" — building the weapons systems that ensure conflicts never need to happen. Castelion is one of the few companies in the hypersonics space that has moved beyond concepts to actual production deliverables, with government contracts across multiple branches of the military and a $23M+ Navy order for 50 units in calendar year 2027.
Backed by over $469M in funding from top-tier investors including Andreessen Horowitz, Lightspeed Venture Partners, and General Catalyst, Castelion is scaling rapidly. The company is building what it anticipates will become the preeminent hypersonics campus in the country — including a $150M, 1,000-acre solid rocket motor manufacturing facility in Rio Rancho, New Mexico, alongside its headquarters in Torrance, California.
Castelion's culture is defined by technical excellence, ownership, and velocity. Engineers own meaningful subsystems on the vehicle and are responsible for driving their success. The company follows a responsible engineering model inspired by SpaceX, where individuals choose the highest-value work and are empowered to cultivate resources and partnerships to deliver results. The engineering bar is exceptionally high — attracting elite talent who want to be surrounded by other elite talent.
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Job details
Location
rio rancho, nm
Funding
Total raised
$464M
Last stage
Growth
Investors
Founders
What happens next.
No applications, no recruiter spam. Just the intro.
Confirm the fit
A few questions to make sure this role is the right shape for you. Two minutes.
I pitch you to the company
I write the intro, send it to the founder, and handle the back-and-forth.
A meeting lands on your calendar
If they’re a yes, I book the chat. You show up — that’s the whole job-hunt.
