Senior Modeling & Simulation Engineer: National Security Missions

K2 is building the largest and highest-power satellites ever flown, unlocking performance levels previously out of reach across every orbit. Backed by $450M from leading investors including Altimeter Capital, Redpoint Ventures, T. Rowe Price, Lightspeed Venture Partners, Alpine Space Ventures, and others – with an additional $500M 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 planned through 2026 and 2027, we're Building Bigger to develop the solar system and become 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 groundbreaking Series C space startup. The Role You will build the modeling and simulation capabilities that let us design, verify, and operate spacecraft for demanding national security missions. You will simulate and verify the software that flies and orchestrates some of the largest satellites ever flown, and model how those systems perform against real mission objectives, threats, and operational constraints. As a senior member of the team, you will drive solutions end-to-end across the software stack, make changes to vehicle control software where needed, set technical direction, and mentor other engineers. In your first 3 months you will generalize our simulation tools to operate in classified contexts, modeling multiple spacecraft and mission profiles, demonstrating robust performance in contested and demanding environments. In your first 6 months you will design many-agent, mission-level simulations and tools for operating entire constellations, directly informing mission assurance and critical company and program decisions. This role supports classified national security programs. Work is performed on-site in a secure environment and requires an active TS/SCI clearance and US citizenship. Responsibilities Develop mission-level modeling and simulation of national security space missions, capturing operational objectives, environments, and constraints. Model and analyze constellation-level capability and performance against mission requirements, including network coverage, beam planning, and resilience in contested environments. Support work on classified programs in accordance with all applicable security requirements. Create and maintain simulation software infrastructure for our 20kW+ spacecraft. Develop physics-based software models of spacecraft subsystems, including propulsion, attitude control, power, and communications systems. Create and utilize robust tools to allow for rapid deployment of quality code. Perform data analysis and anomaly investigation to identify and resolve on-orbit problems. Support integration and testing of spacecraft subsystems. Set technical direction, review designs and code, and mentor junior engineers. Qualifications Active TS/SCI clearance, or a TS/SCI held within the last 12 months, and US citizenship. Current or previously held Special Access Program (SAP) access. Prior experience working on classified national security programs and in secure/SCIF environments, including familiarity with handling classified information and program security protocols. Bachelor's degree in physics, aerospace/mechanical/electrical engineering, computer science, math, or a STEM field 5+ years of professional modeling and simulation experience. Development experience in Rust, C++, or similar compiled language. Experience using scientific Python (NumPy, SciPy, etc.), Julia, MATLAB, or similar. Demonstrated ability to own complex systems end-to-end and guide the work of other engineers. Nice to Have Master's or PhD in physics, aerospace/mechanical/electrical engineering, computer science, math, or a STEM field. Experience with mission-level or campaign-level modeling and simulation for defense or national security applications. Experience working in Rust production environments. Experience defining and creating simulation systems. Experience with Monte Carlo simulations and probability/statistics. Experience with linear algebra, controls, and/or orbital mechanics. Experience with space communication modeling (RF, ground stations). Basic knowledge of electronics, Linux, and computer architecture. Experience with continuous integration and continuous delivery systems. Compensation and Benefits Base salary range for this role is $160,000 - $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 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.S. citizens, lawful permanent residents (i.e., Green Card holders), and certain protected individuals (e.g., refugees/asylees, American Samoans). Please consult with a knowledgeable advisor if you are unsure whether you are a “U.S. Person.”The person hired for this role will have access to information and items controlled by U.S. export control regulations, including the export control regulations outlined in the International Traffic in Arms Regulation (ITAR). The person hired for this role must therefore either be a “U.S. person” as defined by 22 C.F.R. 120.15 or otherwise eligible for a federally issued export control license. Equal Opportunity K2 Space is an Equal Opportunity Employer; employment with K2 Space is governed on the basis of merit, competence and qualifications and will not be influenced in any manner by race, color, religion, gender, national origin/ethnicity, veteran status, disability status, age, sexual orientation, gender identity, marital status, mental or physical disability or any other legally protected status. #J-18808-Ljbffr K2 Space