Navigation Engineer II

## Job Details New ideas are all around us, but only a few will change the world. That’s our focus at JPL. We ask the biggest questions, then search the universe for answers - literally. We build upon ideas that have guided generations, then share our discoveries to inspire generations to come. Your mission - your opportunity - is to seek out the answers that bring us one step closer.

If you’re driven to discover, create, and inspire something that lasts a lifetime and beyond, you’re ready for JPL. Located in Pasadena, California, JPL has a campus-like environment situated on 177 acres in the foothills of the San Gabriel Mountains and offers a work environment unlike any other: we inspire passion, foster innovation, build collaboration, and reward excellence.

The Jet Propulsion Laboratory (JPL) seeks a Navigation Engineer to support Earth’s gravity-field recovery, precise orbit determination, and simulation activities for the Gravity Recovery and Climate Experiment Follow-On (GRACE-FO) and Gravity Recovery and Climate Experiment–Continuity (GRACE-C) missions.

This position focuses on developing, implementing, and validating methods and software to estimate Earth’s gravity field and its temporal variations from spacecraft tracking and instrument measurements. JPL’s Mission Design and Navigation Section develops navigation methods and tools, designs spacecraft trajectories, and navigates spacecraft to their destinations.

The Solar System Dynamics Group (SSD), within JPL’s Mission Design and Navigation Section, studies the orbits and physical characteristics of natural bodies throughout the solar system.

Its work includes: - Characterizing gravity fields, rotation, and shape using spacecraft and ground-based observations. - Computing and predicting the orbits of natural solar system bodies. - Assessing potential Earth impacts by near-Earth objects. - Developing scientific models and analysis methods. - Maintaining and disseminating ephemerides and related dynamical information.

SSD team members collaborate with scientists and engineers throughout the United States and around the world to investigate planetary interiors, improve dynamical models, and support mission planning and scientific investigations.

The Navigation Engineer will be a member of the Solar System Dynamics Group and will report administratively to the Group Supervisor and programmatically to the relevant program or project leads. ## Primary tasks will include but are not limited to - Perform precise orbit determination, gravity-field recovery, and simulation studies in support of GRACE-FO and GRACE-C. - Develop, implement, test, and maintain scientific software for processing spacecraft observations and estimating orbital, gravity-field, and instrument parameters. - Process and analyze relevant mission data, including intersatellite microwave and laser ranging, GPS/GNSS observations, accelerometer measurements, and spacecraft attitude data, as applicable to each mission. - Estimate spacecraft orbital states, gravity-field coefficients, accelerometer calibration parameters, and other relevant model parameters, together with their uncertainties. - Apply and evaluate dynamical and observation models, including models of gravitational and nongravitational accelerations, tides, and atmospheric and oceanic mass variability. - Assess data quality, select appropriate observation weights, identify anomalous measurements, and investigate systematic errors in orbit and gravity-field solutions. - Conduct covariance, sensitivity, and error-budget analyses to evaluate the effects of measurement errors, instrument performance, and modeling assumptions on gravity-field recovery. - Validate recovered gravity fields and orbit solutions through residual analysis, comparisons with independent solutions or observations, and other appropriate diagnostic methods. - Present analysis results, simulation findings, and uncertainty assessments to project scientists, technical leads, and collaborators. - Collaborate with colleagues to document methods and publish research results in peer-reviewed journals. ## Additional responsibilities may include - Contribute to trade studies involving measurement accuracy, data types, processing strategies, and gravity-recovery performance. - Develop and assess improved physical models, estimation methods, and computational tools. - Support the development and testing of processing capabilities for GRACE-C. - Prepare technical documentation, status reports, and presentations for project reviews. - Coordinate with engineers, scientists, and external collaborators on assigned technical activities. - Take responsibility for defined analysis or software-development tasks, including planning, execution, verification, and reporting. ## Required Qualifications - Bachelor’s degree in aerospace engineering, Astronomy, or related technical discipline with typically a minimum of 3 years of related experience; master’s degree in similar disciplines with a minimum of 1 years of related experience; or PhD in similar discipline. - Demonstrated experience in satellite gravity-field recovery or closely related spacecraft-based gravity estimation, including hands-on estimation of gravity-field parameters from tracking observations. - Strong knowledge of orbital dynamics, statistical estimation, numerical methods, and the mathematical foundations of gravity-field modeling. - Experience with precise orbit determination and the estimation of dynamical or instrument parameters from spacecraft measurements. - Understanding of measurement weighting, parameter observability, correlations, covariance analysis, and systematic errors. - Proficiency in scientific programming using one or more languages such as Fortran, Python, C++, or MATLAB. - Experience developing, testing, debugging, and documenting scientific analysis software. - Ability to evaluate technical results critically and communicate findings clearly to technical audiences. - Ability to work independently on assigned tasks and collaborate effectively within a multidisciplinary team. ## Preferred Qualifications - Experience similar to recovering Earth’s time-variable gravity field from GRACE or GRACE-FO. - Familiarity with GRACE, GRACE-FO, or GRACE-C measurement architectures and instrument characteristics. - Experience processing or modeling intersatellite ranging, GPS/GNSS, accelerometer, and attitude observations. - Experience estimating spherical harmonic gravity-field coefficients and mascon models and evaluating the resulting solutions. - Familiarity with tidal models, atmospheric and oceanic de-aliasing products, reference frames, Earth orientation parameters, and nongravitational force modeling. - Experience with accelerometer calibration, ranging-system errors, colored measurement noise, or regularization methods. - Experience with large-scale estimation problems, efficient numerical linear algebra, or high-performance computing. - A publication record demonstrating contributions to spacecraft-based gravity-field recovery, precise orbit determination, or closely related research. - Experience with Fortran-based scientific software and Python-based analysis workflows. - Familiarity with MONTE, particularly for maintaining existing processing tools. - Ability to lead defined technical tasks and collaborate across organizational or institutional boundaries.

JPL has a catalog of benefits and perks that span from the traditional to the unique. This includes a variety of health, dental, vision, wellbeing, and retirement plans, paid time off, learning, rideshare, childcare, flexible schedule, parental leave and many more. Our focus is on work-life balance, and living healthy, fulfilling lives as we Dare Mighty Things Together.

For benefits eligible positions, benefits are effective the first day of the month coincident with or immediately following the employee’s start date. For further benefits information click Benefits a