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Principal GNC Engineer I

Posted 3 hours agoAvionics
Compensation
$142,000–$189,500/year

Job Description

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 actively seeking passionate, collaborative, energetic, and forward-thinking individuals to join our team.

We are looking to add an experienced Principal GNC Engineer I to our team. If you are great at what you do, enjoy working in a startup environment, and are passionate about developing GNC systems for leading-edge spacecraft, and aerospace communication systems, we would like to hear from you.
In this position, you will draw on your experience on previous spacecraft to operate on a small team in the design and analysis of GNC systems for CesiumAstro satellites and payloads. You will be responsible for Guidance, Navigation, and Control through all stages of design, integration, test, and operations. As such, you will perform trade studies, lead design reviews, create models, and complete simulations and system testing. You will build, test, and fly hardware and software.
As a CesiumAstro spacecraft team member, you will work on a small team to develop satellites and put them in orbit. Your work will have a direct impact on the success of the company. You will work closely with the engineering team, program management to ensure the successful build and launch of our satellite. Element will be the largest, most powerful rideshare satellite in LEO. We’re launching eight of them in the next four years, starting with our first launch this year. Together, our small team will design, build, and iterate to reduce mass and cost while increasing performance, reliability, and manufacturability of a new generation of satellites. Let’s build!

JOB REQUIREMENTS AND MINIMUM QUALIFICATIONS

  • Master of Science (MS), or Doctorate (Ph.D.) degree in Aerospace Engineering from an accredited university or institution
  • Minimum of 9 years of industry experience in satellite attitude and orbit systems
  • Deep expertise in spacecraft attitude estimation, guidance, and control, including nonlinear state estimation theory and implementation (e.g., Extended Kalman Filters (EKF), Multiplicative EKF (MEKF), Unscented Kalman Filters (UKF), or other nonlinear observers); coordinate frame transformations; linear algebra; and nonlinear systems
  • Experience with multiple spaceflight missions from concept to operations
  • Experience in low earth orbit satellites
  • Experience with post-CDR test failures and on-orbit failures that guide your design and test philosophies
  • Experience with successful and unsuccessful recovery from on-orbit failures
  • Experience in conceptualization, architecture design, requirements specification, design, test, and operations of various GNC architectures and components
  • Familiarity with space mission simulation tools such as STK, Basilisk, GMAT, or FreeFlyer
  • Experience defining spacecraft trajectories and orbital requirements
  • Fluency with Python and C++, or other modeling languages
  • Familiarity with spacecraft mission design including events, pointing modes, maneuver planning, and operations
  • Excellent written and verbal communication skills
  • PREFERRED EXPERIENCE

  • Demonstrated experience designing, implementing, tuning, and validating flight-grade state estimators, including covariance propagation, bias estimation, sensor fusion (e.g., IMU, star tracker, GNSS, magnetometer), and Monte Carlo-based performance analysis
  • Experience performing observability analysis, estimator consistency analysis (e.g., NEES/NIS), and robustness evaluation under sensor degradation or fault conditions
  • Experience architecting end-to-end ADCS estimation pipelines, including fault detection, measurement rejection, mode-dependent filter configurations, and on-orbit estimator anomaly resolution
  • CubeSat and SmallSat experience
  • Hands-on experience with spacecraft instrumentation, subsystems, and test labs
  • Experience with multiple mission simulation and flight architectures which drives your vision for the next generation of space software
  • Experience in LEO, MEO, GEO, and deep space satellites
  • Experience with communications satellites
  • CesiumAstro considers several factors when extending an offer, including but not limited to, the role and associated responsibilities, a candidate’s work experience, education/training, and key skills. Full-time employment offers include company stock options and a generous benefits package including health, dental, vision, HSA, FSA, life, disability and retirement plans.
    CesiumAstro is an Equal Opportunity employer. All qualified applicants will receive consideration for employment without regard to race, color, religion, sex, national origin, disability, protected Veteran Status, or any other characteristic protected by applicable federal, state, or local law.

    Please note: CesiumAstro does not accept unsolicited resumes from contract agencies or search firms. Any unsolicited resumes submitted to our website or to CesiumAstro team members will be considered property of CesiumAstro, and we will not be obligated to pay any referral fees.

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    Job Details

    Category
    Avionics
    Employment Type
    Contract
    Location
    Westminster, CO
    Posted
    Mar 1, 2026, 01:07 PM
    Listed
    Mar 1, 2026, 01:10 PM
    Compensation
    $142,000 - $189,500 per year

    About CesiumAstro

    Part of the growing space industry ecosystem pushing humanity toward interplanetary exploration.

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