The Role

As a Mechanical Engineer - Active Cooling, you will be the responsible engineer for the liquid cooling loop that keeps our on-orbit GPU compute hardware temperature controlled. This is a hands-on role that sits at the intersection of fluid systems and mechanical design. You will architect the pumped coolant loop, select and size its component (pumps, valves, accumulators, cold plates, instrumentation, etc) and own the mechanical packaging, structures, and interfaces that integrate it into the spacecraft. You will own this hardware end to end, from concept and analysis through the ground testbeds used to prove it out, qualification, and on-orbit operation.

You will work closely with thermal, power, structures, avionics, propulsion, and software teams to deliver an integrated cooling solution. We're looking for a strong fluids background paired with strong mechanical design skills. Someone who can move quickly, iterate often, and take full ownership of hardware that directly determines whether our compute payload survives and performs in orbit.

Responsibilities

• Own the design of the spacecraft liquid cooling loop for GPU compute hardware from concept through flight, including cold plates, pumps, valves, accumulators, heat exchangers, tubing, fittings, and instrumentation.
• Perform pressure-drop, flow, and thermal-fluid analyses to size the loop and predict system behavior across the full mission profile, balancing heat rejection, pump power, mass, and reliability.
• Design the mechanical packaging, structures, mounts, and mechanisms that house and integrate the cooling loop, and couple it to radiators and the broader thermal control system.
• Design, build, and operate ground testbeds and dev rigs to characterize components, validate the loop, and de-risk the flight design ahead of qualification.
• Develop and execute proof-pressure, leak, flow, thermal-vacuum, and qualification/acceptance test programs to verify flight-worthiness.
• Author and maintain schematics, drawings, interface control documents, analysis reports, test procedures, and release/configuration records.
• Select, size, and integrate coolant loop components to meet performance, mass, and reliability requirements, and work with suppliers to ensure high-quality, scalable production.
• Diagnose and resolve cooling-system anomalies during integration and test, applying root-cause analysis and implementing corrective actions.
• Partner with thermal, power, structures, avionics, propulsion, and software teams to ensure the cooling loop integrates seamlessly within the overall spacecraft architecture.
• Embrace a fast-paced development environment, driving quick design cycles, hardware builds, and test campaigns to accelerate the program schedule.

Basic Qualifications

• BS or MS in Mechanical Engineering, Aerospace Engineering, or a related field
• 3+ years of experience designing or analyzing fluid systems and/or mechanical hardware in aerospace, automotive, energy, data-center cooling, or other high-performance environments
• Strong fluids fundamentals: compressible/incompressible flow, thermodynamics, heat transfer, and pressure systems
• Hands-on experience with fluid components including pumps, valves, regulators, tubing, and instrumentation
• Experience taking hardware from concept through build and test, with hands-on integration and test experience
• Strong mechanical design fundamentals in mechanics, materials, and thermal systems
• Proficiency with CAD (e.g., NX, SolidWorks, or similar)
• Experience working in fast-paced, hardware-focused development environments

Preferred Qualifications

• Direct experience designing pumped liquid cooling loops, two-phase cooling, or cold-plate/coolant systems for high heat-flux electronics or GPU/compute hardware
• Experience designing for space environments (thermal, vibration, vacuum) and background in spacecraft structures, mechanisms, or thermal systems
• 3+ years of experience with spacecraft, launch vehicle, satellite fluid, or thermal systems
• Familiarity with thermal control systems and thermal-fluid coupling at the spacecraft system level
• Experience with FEA, thermal, and fluid simulation tools.
• Knowledge of aerospace standards (MIL-SPEC, NASA-STD, ECSS) and spaceflight hardware qualification and acceptance margins
• Hands-on experience with prototyping, machining, test setups, leak testing, or pressure vessel design
• Startup or early-stage hardware experience; comfort operating with significant technical ambiguity

Compensation and Benefits

The salary range for this position is $100,000 - $300,000 annually. The actual base salary offered will depend on factors such as job-related skills, experience, qualifications, and internal equity.

Equity in Cowboy Space Corp.

Employees and their eligible dependents may enroll in medical, dental, and vision insurance

401(k) retirement savings plan

Paid time off

10 paid holidays per calendar year

Paid parental leave

Relocation assistance if applicable

Daily lunch in the office and a fully stocked kitchen with beverages and snacks

ITAR Requirements

Export Control Requirement: To conform to U.S. Government space technology export regulations, including the International Traffic in Arms Regulations (ITAR), applicants must be a U.S. citizen, lawful permanent resident of the U.S., protected individual as defined by 8 U.S.C. 1324b(a)(3), or eligible to obtain the required authorizations from the U.S. Department of State. Learn more about ITAR here.

Disclaimer

This job description is a summary of the primary duties and responsibilities of the job and position. It is not intended to be a comprehensive or all-inclusive listing of duties and responsibilities. Contents are subject to change at Cowboy Space Corp.'s discretion.