Spacecraft Thermal Engineer; Mid-Career - Millennium Space Systems

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.

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 include 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.

• 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
• Assist 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 aid 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.

• Must meet Export Control compliance requirements, therefore a “US Person” as defined by 22 C.F.R. 120.15. “US Person” includes US Citizen, lawful permanent resident, refugee, or asylee.
• Ability to obtain and maintain a TS/SCI Security Clearance

• Bachelor’s degree in Mechanical Engineering, Aerospace Engineering, Physics, or other relevant fields
• 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

• Active TS/SCI Clearance

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

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.

This role will be on 1st shift.

At Millennium Space Systems, a Boeing Company, we strive to deliver a Total Rewards package that will attract, engage and retain top talent. Elements include competitive base pay and variable compensation opportunities, health insurance, flexible spending accounts, health savings accounts, retirement savings plans, life and disability insurance programs, and various paid and unpaid time‑away programs. Pay is based upon candidate experience and qualifications, as well as market and business considerations.

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

Applications for this position will be accepted until Jun. 22, 2026.

Relocation assistance is not a negotiable benefit for this position.

Employer will not sponsor applicants for employment visa status.

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.