Portfolio Careers

Senior Thermal Analysis Engineer

Portal Space Systems

Portal Space Systems

Bothell, WA, USA
Posted on Feb 22, 2026

The Thermal Analysis Engineer is responsible for performing thermal modeling and analysis in support of high-temperature thruster hardware and spacecraft bus systems. This role is responsible for predicting temperature distributions, assessing thermal margins, and defining thermal control strategies for high-temperature thruster hardware. It is also responsible for modeling on-orbit thermal environments and supporting spacecraft bus thermal control design. The position works closely with design, fluids, structural, electrical, and systems engineers to develop thermal requirements, predictions, and solutions at both component- and system-levels.

Responsibilities

HEX Thruster Thermal Analysis and Development

  • Develop transient, high geometric fidelity thermal models of high-temperature thruster
  • Predict transient temperature distributions, radiation in, re-radiation out, and conduction to bus
  • Assess thermal margins for thruster and nearby spacecraft hardware
  • Identify and design thermal control approaches of the thruster, including radiation reception, re-radiation mitigation, and conduction paths
  • Support propulsion test campaigns with pre-test predictions, instrumentation planning, and post-test data reduction and model correlation

Spacecraft Thermal Analysis

  • Design and develop spacecraft thermal control systems including passive and active solutions
  • Perform thermal modeling, simulation, and analysis using Thermal Desktop, SINDA/FLUINT
  • Generate and maintain thermal models across multiple mission phases
  • Collaborate closely with systems engineering, mechanical design, and electrical engineering teams to ensure cohesive spacecraft development

Basic Qualifications

  • Bachelor’s or Master’s degree in Mechanical Engineering, Aerospace Engineering, or related field
  • 5+ (for Bachelors) or 3+ (for Masters) years of experience in modeling and designing thermal solutions for propulsion hardware, spacecraft, and/or satellites
  • Proficiency in industry-standard thermal analysis tools (e.g., Thermal Desktop, SINDA/FLUINT, Ansys Mechanical)
  • Strong understanding of orbital thermal environments and space mission thermal challenges

Preferred skills & Experience

  • Experience analyzing and developing high-temperature propulsion hardware
  • Deep understanding of heat transfer fundamentals (e.g., conduction, convection, radiation, and high-temperature material behavior)
  • Proficiency in using first principals hand calcs to create quick predictions and sanity checks for detailed models
  • Excellent communication and documentation skills

Compensation & Benefits

Base salary is just one part of your total rewards package at Portal. You may also be eligible for long-term incentives in the form of company stock, stock options, or long-term cash awards, as well as potential discretionary bonuses and the ability to purchase additional stock at a discount through an Employee Stock Purchase Plan. You will also receive access to comprehensive medical, vision, and dental coverage. Portal is planning to establish future access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, and various other discounts and perks. Employees typically have 2-3 weeks of paid vacation per year plus company holidays.

ITAR Requirements

To conform to U.S. Government export regulations, the applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State.