Principal Thermal Engineer

Infleqtionis a global quantum technology company solving the world’s most challenging problems. The company harnesses quantum mechanics to build and integrate quantum computers, sensors, and networks. From fundamental physics to leading edge commercial products, Infleqtion enables “quantum everywhere” through our ecosystem of devices and platforms.

Infleqtion has 6 office locations, operating out of Boulder/Louisville, CO;
Madison, WI;
Chicago, IL;
Oxford, UK; and Melbourne, AU. This position is a full-time, hybrid position which will be located in our Louisville, CO office.

Infleqtion is seeking a highly experienced thermal analyst; this role is responsible for keeping our sensor head and electronics temperature limits in check when performing physics sequences enabling quantum sensing operations in space.

The role requires close collaboration with our prime customer(s), internal management, researchers, systems engineers, aerospace experts, manufacturing partners, suppliers, and external subcontractors. The individual will actively engage customers and partners throughout the program lifecycle, ensuring delivery against milestones and commitments while maintaining alignment with Infleqtion’s internal product lifecycle and quality standards. Cross‑disciplinary engagement is expected, with this role driving technical alignment across hardware, software, systems, and mission domains.

Up to 10% travel may be required to support off‑site testing, deliveries, and integration.

The duties and responsibilities outlined below include essential functions of the role. Depending on business needs, this role may perform a combination of some or all the following duties. Duties, responsibilities, and activities may change, or new ones may be assigned.

• Update the existing system‑level thermal model with the appropriate fidelity to ensure the physics sequence operates within space environmental constraints
• Conduct regular technical discussions and model reviews of in‑house and subcontractor electronic card and enclosure cooling designs, including some of them which have unique thermal requirements
• Develop and test EDU thermal designs for microgravity environments
• Adapt flight thermal designs for microgravity testing
• Serve as a hands‑on engineer with experience building both EDU and flight hardware
• Install MLI and bond heaters and thermistors using ASTM‑E595 approved materials
• Present progress and results to senior management and the end customer
• Execution of modeling, simulation, and analytical efforts required to enable product performance
• Integration of subsystems and their thermal requirements / interfaces
• Identifying and engaging key suppliers
• Following Infleqtion’s Product Lifecycle Process and supporting Phase gate reviews, critical design reviews, and executive updates
• Supporting development of risk management plans and risk resolution, and supporting reliability analysis and continuous improvement
• Coaching and mentoring junior engineers
• Other duties as assigned or required

• Bachelor’s degree required, with a focus in thermal design or a related engineering field
• 6+ years of relevant and progressive experience in similar roles
• Hands on engineer with experience building both EDU and flight hardware
• Experience installing MLI, bonding of heaters and thermistors using ASTM‑E595 approved materials
• Leverages AI appropriately; understands limitations of current offerings
• Excellent proficiency in design first principles
• Expert level understanding of opto‑mechanics, including free space optical mounting, collimator design, free‑space and fiber coupled alignment design and tolerancing
• Demonstrated Dfx (design to cost etc.)
• Understanding of ASTM E595 – how to choose materials for space
• Experience designing custom flexure mounts for both optics and instruments
• Tolerance analysis
• Hands on engineer with experience building both EDU and flight hardware
• Uses AI appropriately for leverage; understands limitations of current platforms
• Ability to travel domestically and (potentially) internationally up to 10%

• Comfortable with a hands‑on approach to…