GNC Engineer - Navigation Sensors and Algorithms

K2 is building the largest and highest-power satellites ever flown, unlocking performance levels previously out of reach across every orbit. Backed by over $1 billion in total funding from leading investors including Altimeter Capital, ICONIQ, Kleiner Perkins, Lightspeed Venture Partners, Redpoint Ventures, and T. Rowe Price — and with over $1 billion in signed contracts across commercial and US government customers, we're mass-producing the highest-power satellite platforms ever built for missions from LEO to deep space. The rise of heavy-lift launch vehicles is shifting the industry from an era of mass constraint to one of mass abundance, and we believe this new era demands a fundamentally different class of spacecraft. Engineered to survive the harshest radiation environments and to fully capitalize on today's and tomorrow's massive rockets, K2 satellites deliver unmatched capability at constellation scale and across multiple orbits. With multiple launches in 2027 and plans to scale to 100 satellites a year, we're Building Bigger — helping develop the solar system and build toward a Kardashev Type II (K2) civilization. If you are a motivated individual who thrives in a fast-paced environment and you're excited about contributing to the success of a high-growth Series D-funded company, we'd love for you to apply. The Role You will own the navigation and sensing chain that tells K2 spacecraft where they are, how they are oriented, from the physical sensor hardware all the way to the estimation algorithms and flight software executing those algorithms. This is a blend of a hands-on hardware and software role, requiring you to be the GNC point of contact with Avionics, flight software, and Test teams. In the first 6 months, you will help to design and characterize the software driver for the GNSS receivers, standing up develop testing to validate GNSS performance and link budgets as a function of altitude, and feeding these learnings back into both hardware and on board filter design. In the first year you will support multiple K2 launches of the stacked configuration, supporting operations as the GNC point of contact. Responsibilities

Design, implement, and verify onboard estimation algorithms for orbit and attitude determination (EKF/MEKF/UKF, batch estimators, sensor fusion)

Develop high-altitude GNSS navigation capability for MEO and GEO, including sidelobe and weak-signal tracking, receiver selection, and onboard orbit filtering

Improve measurement and system timing accuracy from sensor output to GNC ingestion, ensuring low-latency and low-jitter navigation

Develop and run GNC sensor calibration on the ground and on orbit.

Select, specify, and integrate navigation sensors (GNSS receivers, IMUs, magnetometers, star trackers) in fault tolerant architectures to support robust next generation capabilities

Build sensor models and estimation components in our simulation framework, and bring algorithms from prototype into production flight software

Support on-orbit commissioning and navigation performance analysis during mission operations

Defining pass/fail performance criteria for GNC hardware during acceptance testing and supporting investigation of out-of-spec hardware

Shape the future of the GNC team by recruiting, interviewing, and mentoring engineers

Qualifications

Master’s degree or higher in aerospace, electrical, or mechanical engineering, physics, or a related field

2+ years of experience in navigation, estimation, or sensor engineering for spacecraft.

Strong grasp of estimation theory, with hands-on experience implementing filters for real time systems

Hands-on experience with navigation hardware in the lab

Experience with Python, Julia, C/C++, or Rust for algorithm development, implementation, hardware test, and simulation

Nice to Have

Experience with early-stage spacecraft conceptual design, i.e. “clean sheet” design work

Previous experience with high altitude/cis-lunar GNSS architectures

Knowledge of GNSS link budgets and antenna pattern modeling

Experience with optics, such as star trackers, cameras, and optical navigation

Ability to characterize inertial sensors through Allan variance and PSD analysis to motivate both simulation and flight software development.

Experience with magnetometer calibration and bias compensation - design and operation of Helmholtz cage and zero gauss chamber.

Hands-on experience with GNSS simulators, attenuators, LNAs, and Spectrum Analyzer.

Experience with vehicle level polarity and run-for-record testing.

Basic power electronics and serial protocol + ethernet knowledge

Avionics radiation basics (transient and dose effects), how they manifest, and FDIR strategies at the hardware and software layer to mitigate these behaviors.

Exposure to environmental testing (SMC-S-016 and/or HALT/HASS) to facilitate root-cause-analysis investigations during acceptance/qualification testing of GNC components.

Compensation and Benefits:

Base salary range for this role is $110,000 - $200,000 + equity in the company

Salary will be based on several factors including, but not limited to: knowledge and skills, education, and experience level

Comprehensive benefits package including paid time off, medical/dental/vision coverage, life insurance, paid parental leave, and many other perks If you don’t meet 100% of the preferred skills and experience, we encourage you to still apply! Building a spacecraft unlike any other requires a team unlike any other and non-traditional career twists and turns are encouraged! If you need a reasonable accommodation as part of your application for employment or interviews with us, please let us know. Export Compliance As defined in the ITAR, “U.S. Persons” include U