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Updated 2026-06-13 13:00 UTC·© 2025–2026 RoleSuite
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Principal Mechanical Engineer I

Cesium Astro · Westminster, CO

Please Note: To conform with the United States Government Space Technology Export Regulations, the applicant must be a U.S. citizen, lawful permanent resident of the U.S., conditional resident, asylee or refugee (protected individuals as defined by 8 U.S.C. 1324b(a)(3)), or eligible to obtain the required authorizations from the U.S. Department of State.

At CesiumAstro, we are developers and pioneers of out-of-the-box communication systems for satellites, UAVs, launch vehicles, and other space and airborne platforms. We take pride in our dynamic and cross-functional work environment, which allows us to learn, develop, and engage across our organization. If you are looking for hands-on, interactive, and autonomous work, CesiumAstro is the place for you.

We are looking to add a Principal Mechanical Engineer I to our team. If you enjoy working in a startup environment, and are passionate about developing leading-edge hardware for satellites, spacecraft, and aerospace systems, we would like to hear from you.

In this position, you will be responsible for the mechanical design of Cesium products through all phases of the development process. The ideal candidate will have extensive experience in electronics packaging design, mechanical simulations and analyses, computer-aided design (CAD), spacecraft mechanical interfaces, and environmental qualification of electronic assemblies.

As a principal mechanical team member, you will be responsible for mechanical designs from initial concept design through requirements definition, detailed design, simulation, analysis, manufacturing, testing, qualification, and in-orbit support of Cesium's products. Required skills and experience include thermal management design, precision machining principles, thermal simulation and analysis, shock and vibration simulation and analysis, electromagnetic interference/compatibility (EMI/EMC) mitigation techniques, geometric dimensioning and tolerancing (GD&T), finite element analysis (FEA), and cost analysis to develop, validate, and optimize mechanical designs. Principal engineers also serve as technical and professional mentors in their field.

The successful candidate will also present engineering design review materials to our customers and executive team, as well as participate in proposal-writing efforts. As such, excellent written and verbal communication skills are required.

JOB REQUIREMENTS AND MINIMUM QUALIFICATIONS

  • A Bachelor of Science (BS) or Master of Science (MS) degree in Mechanical or Aerospace Engineering from an accredited university or institution.
  • 9 years of industry experience in design and analysis of electronics packaging, including thermal, vibration, and stress dynamics.
  • Demonstrated expertise in packaging high-power and high-density electronic assemblies.
  • Strong understanding of thermal management techniques for spaceborne and/or high-power electronics. 
  • Experience designing hardware for launch and spaceflight environments (or similar). 
  • Expertise in finite element analysis and thermal simulation tools (Ansys or similar).
  • Expert-level proficiency with professional mechanical CAD tools (SolidWorks or similar).
  • Experience with precision machining, advanced manufacturing processes, and tolerance analysis. 
  • Experience with EMI/EMC mitigation techniques.
  • Strong understanding of GD&T and aerospace drawing practices. 
  • Excellent written and verbal communication skills.
  • PREFERRED EXPERIENCE

  • Experience packaging digital, power or RF printed circuit board assemblies. 
  • Experience with spacecraft payloads, avionics, or power systems. 
  • Knowledge of NASA, DoD, ESA, or commercial space qualification standards. 
  • Experience with thermal vacuum testing and spacecraft environmental qualification. 
  • Familiarity with materials selection for radiation and outgassing environments. 
  • Hardware pay context

    Based on 2,278 disclosed Hardware salaries on RoleSuite, the role pays a median of $136K/year, with most offers between $110K and $172K (10th–90th percentile: $92K–$208K).

    This posting lists $134K–$161K, in line with the $136K market median.

    See the full Hardware salary breakdown →
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