Lead, Mechanical Engineer (Thermal) - Space Vehicle and Payloads

L3Harris•Fort Wayne, FL

8d•Onsite

About The Position

L3Harris is seeking an experienced Lead Thermal Engineer to lead spacecraft-level thermal design, modeling, and analysis for advanced space-based electro-optical missions. The role is responsible for architecting and validating thermal solutions that support mission success across multiple orbital environments. The engineer will provide technical leadership on spacecraft thermal strategy, mentor engineers, and collaborate with multidisciplinary teams. The position is on-site in Palm Bay, Florida, or Fort Wayne, Indiana, with a 9/80 schedule: employees work nine days every 14 days, totaling 80 hours, and have every other Friday off. Relocation assistance is available to qualified applicants. The candidate must be able to obtain a U.S. security clearance.

Requirements

Bachelor of Science degree in Engineering and at least 9 years of prior relevant experience; or a graduate degree in Engineering and at least 7 years of prior related experience; or at least 13 years of prior related experience in lieu of a degree.
At least 5 years of professional experience using Thermal Desktop.
Prior or current professional experience with thermal design and analysis for space environments or products.
At least 2 years of experience as an IPTL or providing technical leadership to an engineering team.
Ability to obtain a U.S. security clearance.

Nice To Haves

Experience designing for a space environment.
Current security clearance.
Deep understanding of spacecraft materials, thermal coatings, MLI, conductive interfaces, and active thermal-control elements.
Demonstrated success developing, validating, and correlating thermal models to TVAC results.
Ability to lead design reviews, guide complex decision-making, and communicate clearly with customers, leadership, and engineering teams.
Experience working on government, DoD, or national security space missions.
Knowledge of mission-specific environments such as GEO, LEO, cislunar, or deep space.
Broad knowledge of thermal-fluids physics, including heat conduction and convection of multiphase flows.
Experience creating and overseeing the development of thermal testing control logic in SINDA/FLUENT.
Familiarity with structural-thermal-optical (STOP) analysis, deployment-mechanism thermal behavior, or thermal considerations in RF/high-power payloads.
Experience with reliability assessments, derating, and long-duration thermal performance modeling.

Responsibilities

Serve as the technical lead for spacecraft-level thermal design, defining architecture, strategies, and requirements for high-reliability space vehicles.
Develop detailed thermal models and analyses for mission phases and scenarios, including worst-case hot and cold environments, eclipse conditions, and orbital variations.
Lead creation and validation of thermal-control hardware, including radiators, coatings, heat pipes, surface finishes, heaters, insulation, and conductive interfaces.
Own thermal performance budgets and flow down requirements to payload, avionics, structures, and propulsion subsystems.
Evaluate thermal impacts of system trades, configuration changes, power profiles, and operational timelines.
Direct development of thermal math physics models using Thermal Desktop, Flowtherm, SINDA/FLUINT, ESATAN-TMS, or equivalent tools.
Lead spacecraft hardware build, integration, and testing activities, including thermal vacuum (TVAC) planning, execution, anomaly resolution, and correlation of test results to analysis.
Guide environmental considerations for space platforms, including radiation, conduction, convection-free behavior, material properties, surface degradation, and mission-life effects.
Collaborate with systems engineering, mechanical design, power, RF, digital hardware, manufacturing, and mission assurance teams.
Mentor junior and mid-level engineers, establish best practices, and drive continuous improvement in thermal engineering processes.
Prepare thermal requirements, analysis reports, review packages, test plans, and verification matrices.