Spacecraft Thermal Engineer (Mid to Senior Career) - Millennium Space Systems

Boeing; El Segundo (CA); On-site; USD 102,000 - 183,000; Full time

Job summary

Millennium Space Systems, a Boeing Company, is seeking a Thermal Engineer to support development of all spacecraft thermal configurations and testing for the Spacecraft Development Program. The role emphasizes passive and active thermal control, with opportunities in MLI design and flight operations.

Ideal candidates have a BS in Engineering and 2+ years in spacecraft thermal systems, plus proficiency with Thermal Desktop, SINDA/FLUINT, ANSYS, or Thermica.

Qualifications

• Bachelor of Science degree in Engineering (Mechanical / Civil / Aerospace / Materials focus)
• 2+ years of spacecraft thermal systems design, development, analysis or testing
• Proficiency with thermal analysis tools: Thermal Desktop, SINDA/FLUINT, ANSYS, Thermica
• Ability to obtain and maintain a TS/SCI Security Clearance

Responsibilities

• Perform spacecraft thermal design and analyses at the board, component, subsystem, and system level
• Develop thermal models to predict loads, temperatures and margins to support design
• Brief design and analysis materials to program managers, customers, and sponsors
• Identify materials, processes, and facilities to achieve a qualified thermal design and operation
• Assist in proposal and new business development efforts
• Support thermal verification testing on spacecraft systems and components including test design and data analysis
• Develop tools to aid in conceptual designs and post-processing
• Potential to cross-train with MLI team for hands-on support

Skills

Thermal design

Thermal analysis

Education

Bachelor of Science in Engineering

Tools

Thermal Desktop

SINDA/FLUINT

ANSYS

Thermica

Job description

Job Description

At Boeing, we innovate and collaborate to make the world a better place. We’re committed to fostering an environment for every teammate that’s welcoming, respectful and inclusive, with great opportunity for professional growth. Find your future with us.

Job Description

Millennium Space Systems, a part of Boeing Defense, Space and Security (BDS), is a fast, agile small satellite company focused on national security space. Our missions have direct impact to global security, like missile warning and Earth observation.

Our team is curious, bold and innovative. We take risks, innovate and explore new techniques and technologies. We influence change because we challenge the status quo. And when we watch our satellites launch, we know each one of us made it happen.

Job Summary

Thermal Engineers support the Spacecraft Development Program Managers and Chief Systems Engineer through the development of all spacecraft thermal system configurations, designs, analyses, testing, and flight operations. Spacecraft thermal subsystem elements includes all passive and active means of controlling the satellite’s system, subsystem, and component environments within both operating and survival limits during all pertinent system lifetime activities. Thermal engineers also have the opportunity to support MLI blanket design, fabrication, and installation.

This position’s internal job code is Mechanical System Design & Analysis Engineer. Our team is currently hiring for a level 3-4.

Responsibilities

• Perform spacecraft thermal design and analyses at the board, component, subsystem, and system level
• Develop systems and spacecraft element thermal models to predict thermal loads, impacts, and temperature margins to support system design
• Brief design and analysis materials to program managers, customers, and/or sponsors
• Identify all materials, processes, and facilities to achieve a qualified spacecraft thermal design and operation
• Assists in proposal and new business development efforts
• Support thermal verification testing on spacecraft systems and components including test design, test conduct, data reduction, analysis, and reporting
• Support the development of tools to aide in conceptual designs and post-processing analysis
• Potential to cross-train with MLI team for hands‑on support

This position is expected to be 100% onsite. The selected candidate will be required to work onsite at one of the listed location options.

Security Clearance And Export Control Requirements

This position must meet Export Control compliance requirements, therefore a “US Person” as defined by 22 C.F.R.120.15 is required. “US Person” includes US Citizen, lawful permanent resident, refugee, or asylee.

Minimum Qualifications

• Bachelor of Science degree in Engineering (with a focus on Mechanical, Civil, Aerospace Aeronautical or Material Sciences)
• 2 or more years of experience in the design, development, analysis, implementation, testing, and/or operation of spacecraft thermal systems or other related complex thermal systems
• Proficiency with thermal analysis tools (e.g. Thermal Desktop, SINDA/FLUINT, ANSYS, Thermica)
• Ability to obtain and maintain a TS/SCI Security Clearance

Preferred Qualifications

• Active TS/SCI Clearance

Conflict of Interest:

Successful candidates for this job must satisfy the Company’s Conflict of Interest (COI) assessment process

Drug Free Workplace:

Millennium Space Systems, a Boeing Company, is a Drug Free Workplace (DFW) where post offer applicants and employees are subject to testing for marijuana, cocaine, opioids, amphetamines, PCP, and alcohol when criteria is met as outlined in our policies.

Shift:

• This role will be on 1st

Total Rewards:

At Millennium Space Systems, a Boeing Company, we strive to deliver a Total Rewards package that will attract, engage and retain the top talent. Elements of the Total Rewards package include competitive base pay and variable compensation opportunities.

Millennium Space Systems also provides eligible employees with an opportunity to enroll in a variety of benefit programs, generally including health insurance, flexible spending accounts, health savings accounts, retirement savings plans, life and disability insurance programs, and a number of programs that provide for both paid and unpaid time away from work.

The specific programs and options available to any given employee may vary depending on eligibility factors such as geographic location, date of hire, and the applicability of collective bargaining agreements.

Pay is based upon candidate experience and qualifications, as well as market and business considerations.

Summary Pay-Range

• Level 3: $102,000 - $150,000
• Level 4: $124,100 - $182,500

Millennium is DDTC-registered, ITAR-compliant Company. This position is located at a facility that requires special access. Applicants MUST be U.S. citizens and eligible for a security clearance. Additionally, applicants must be willing to apply for and maintain a security clearance. We encourage all interested candidates to apply for any open position for which they feel they are qualified.

Category = Engineering

Applications for this position will be accepted until Oct. 23, 2026

Export Control Requirements:

This position must meet U.S. export control compliance requirements. To meet U.S. export control compliance requirements, a “U.S. Person” as defined by 22 C.F.R.120.62 is required. “U.S. Person” includes U.S. Citizen, U.S. National, lawful permanent resident, refugee, or asylee.

Export Control Details:

US based job, US Person required

Education

Bachelor's Degree or Equivalent Required

Relocation

Relocation assistance is not a negotiable benefit for this position.

Security Clearance

This position requires the ability to obtain a U.S. Security Clearance for which the U.S. Government requires U.S. Citizenship. An interim and/or final U.S. Secret Clearance Post-Start is required.

Visa Sponsorship

Employer will not sponsor applicants for employment visa status.

Shift

This position is for 1st shift

Equal Opportunity Employer:

Boeing is an Equal Opportunity Employer. Employment decisions are made without regard to race, color, religion, national origin, gender, sexual orientation, gender identity, age, physical or mental disability, genetic factors, military/veteran status or other characteristics protected by law.