Lead Nuclear Engineer

About Matter IntelligenceMatter Intelligence is at the forefront of developing cutting-edge airborne and spaceborne sensing systems that integrate precision optics, innovative thermal architectures, spacecraft engineering, and AI-enhanced data analysis. Our advanced systems function effectively in challenging orbital and airborne environments, unlocking new possibilities for Earth observation capabilities.With a proven track record of delivering technologies to Mars for NASA/JPL, designing advanced sensors for U.S. defense, and establishing core infrastructure at OpenAI, our team is now focused on creating the next generation of sensing systems for both space and airborne applications.About the RoleWe are looking for a Senior Thermal Engineer who will take charge of the thermal architecture, analysis, and verification of our precision optical payloads and spacecraft systems. This role encompasses ownership of thermal performance from the initial concept stage through integration, testing, and, where applicable, on-orbit operations.You will be responsible for developing and maintaining intricate thermal models, steering thermal trade studies, supporting STOP performance, and collaborating closely with systems, optomechanical, electronics, and AI & T teams to ensure that flight hardware meets all performance requirements throughout every mission phase.This is a hands-on, analytical, and leadership-focused role suited for an engineer seeking significant technical ownership over hardware that operates in flight.Key ResponsibilitiesThermal Architecture & DesignDefine and lead the thermal architecture for optical payloads and spacecraft subsystems.Design both passive and active thermal control solutions, including radiators, heat pipes, thermal straps, insulation, and cryogenic interfaces.Translate mission-level thermal requirements into subsystem- and component-level designs.Support thermal trades to effectively balance performance, mass, power, and complexity.Thermal Modeling & AnalysisDevelop, maintain, and correlate detailed thermal models using industry-standard tools (e.g., Thermal Desktop, SINDA/FLUINT).Conduct steady-state and transient thermal analyses across all mission phases (launch, ascent, on-orbit hot/cold cases, safe modes).Perform in-depth thermal analysis of precision optical elements (mirrors, mounts, focal plane assemblies), including thermo-elastic distortion.Execute thermal assessments at the circuit card and chassis level.

About VardaLow Earth orbit is open for business. Varda is pioneering the advancement of commercial space infrastructure, from in-orbit pharmaceutical processing to dependable and cost-effective reentry capsules.From life-saving pharmaceuticals to enhanced fiber optics, a myriad of products utilized on Earth today can only be produced in space. Varda is driving innovation in the orbital economy by establishing both the products and infrastructure required for space to directly enhance life on Earth. Our mission is to expand the economic horizons of humanity.Our team is exceptionally equipped to achieve this objective, with leadership and personnel comprising veterans from SpaceX, Blue Origin, leading pharmaceutical companies, and Silicon Valley. Founded in January 2021 by Will Bruey and Delian Asparouhov, Varda is supported by esteemed investors including Khosla Ventures, Lux Capital, Founders Fund, Caffeinated Capital, General Catalyst, and Also Capital.Varda's headquarters is located in El Segundo, California, where we operate offices and a production facility for building, integrating, and testing our vehicles, equipment, and materials. Additionally, Varda has offices in Washington, DC, and Huntsville, AL.Join Varda and contribute to the creation of a thriving in-space ecosystem.

Join Radiant Industries as a Senior Thermal Engineer, where you will play a crucial role in developing innovative thermal solutions for our cutting-edge projects. You will collaborate with a dynamic team of engineers and scientists to enhance product performance through advanced thermal management techniques.

We are seeking a highly skilled and experienced Senior Thermal-Hydraulics Engineer to join our dynamic team at Radiant Industries. In this role, you will be responsible for designing, analyzing, and optimizing thermal-hydraulic systems to enhance our product offerings. Your expertise will play a crucial role in ensuring the efficiency and reliability of our engineering solutions.As a key member of our team, you will collaborate with cross-functional teams to develop innovative designs, conduct simulations, and perform experiments. If you are passionate about engineering and eager to take on new challenges, we invite you to apply!

Join Radiant Industries as a Senior Thermal Analyst, where you will leverage your expertise in thermal analysis to contribute to innovative projects. In this role, you will be responsible for assessing thermal performance and ensuring optimal design solutions for our cutting-edge products.

Join Radiant Industries as a Senior Thermal Modeling Engineer, where you will play a crucial role in developing advanced thermal models for innovative products. You will collaborate with cross-functional teams to ensure thermal performance meets design specifications. Your expertise will contribute to our mission of delivering cutting-edge solutions that enhance user experience.

About VardaPioneering the Future of Low Earth Orbit. Varda is at the forefront of developing commercial space infrastructure, ranging from in-orbit pharmaceutical production to efficient and cost-effective reentry capsules.Our innovations include a variety of products, from life-saving pharmaceuticals to advanced fiber optics, all of which can only be developed in space. Varda is committed to driving progress in the orbital economy by establishing the necessary products and infrastructure to ensure that space can directly enhance life on Earth. Our mission is to expand the economic horizons of humanity.Our exceptional team is composed of veterans from SpaceX, Blue Origin, and major pharmaceutical firms, along with experts from Silicon Valley. Founded in January 2021 by Will Bruey and Delian Asparouhov, Varda has garnered significant support from prestigious investors, including Khosla Ventures, Lux Capital, Founders Fund, Caffeinated Capital, General Catalyst, and Also Capital.Headquartered in El Segundo, California, we operate a production facility where our vehicles, equipment, and materials are designed, integrated, and tested. Additionally, we have offices in Washington, DC, and Huntsville, AL.Join Varda and contribute to building a thriving ecosystem in space.About This RoleThe Thermal Engineer will be responsible for conducting thermal analysis and ensuring optimal thermal performance of our spacecraft systems.

Join Radiant Industries as a Senior Thermal Modeling Analyst and leverage your expertise in thermal systems to drive innovation and excellence. In this pivotal role, you will be responsible for conducting advanced thermal modeling analyses, collaborating with cross-functional teams to develop and enhance thermal solutions, and ensuring that our products meet the highest standards of performance and efficiency.

Important Notice: In accordance with U.S. Government Space Technology Export Regulations, applicants must be U.S. citizens, lawful permanent residents, conditional residents, asylees, refugees, or eligible for required authorizations from the U.S. Department of State.At CesiumAstro, we are at the forefront of innovative communication systems for satellites, UAVs, launch vehicles, and various aerospace platforms. Our vibrant and collaborative work environment fosters learning, growth, and engagement across all levels of our organization. If you seek a dynamic, hands-on, and autonomous work culture, CesiumAstro is the right choice for you.We are eager to welcome a Senior Thermal Engineer I to our expanding team. If you excel in your craft, thrive in a startup setting, and are passionate about pioneering hardware for satellites and aerospace systems, we invite you to apply.In this role, you will take charge of designing, analyzing, and validating thermal control systems for Cesium’s next-generation products. The ideal candidate will possess significant experience in developing and analyzing thermal management systems for satellite electronics and airborne systems, along with a profound understanding of space and aerospace thermal environments.As a senior member of our cross-functional team, you will oversee thermal designs from the initial concept phase through requirements definition, detailed design, simulation/analysis, manufacturing, testing, qualification, and in-orbit support of Cesium’s products. You will collaborate closely with electrical and mechanical engineers to devise highly optimized solutions.The successful candidate will also be responsible for presenting engineering design review materials to customers and upper management, as well as participating in proposal-writing initiatives. Therefore, exceptional written and verbal communication skills are essential.

Join Vardaspace as a Thermal Hardware Engineer specializing in Passive & Active Control Systems. In this role, you will be at the forefront of innovative thermal management solutions, ensuring the efficiency and reliability of our cutting-edge technologies. Collaborate with a dynamic team to design, develop, and test thermal hardware components that meet rigorous performance standards.

Join our team at Radiant Industries as a Structural & Thermal Analyst - Turbomachinery. In this pivotal role, you will oversee the structural, thermal, and mechanical performance of high-speed rotating machinery, including compressors, turbines, and pumps utilized in our power generation and primary cooling systems.You will collaborate with mechanical designers, manufacturing engineers, and testing teams to ensure our hardware meets performance expectations under extreme mechanical and thermal conditions. Your contributions will significantly impact Radiant’s mission through trade studies, iterative design, prototype development, simulations, and comprehensive testing.Responsibilities:Conduct structural and thermal analyses of turbomachinery components and assemblies (compressors, turbines, rotors, electric motors, bearings, seals, and housings) to inform design decisions and ensure reliability under operational and transient conditions.Assess static and dynamic mechanical performance, thermal stresses, and coupled thermal-structural interactions.Perform fatigue, durability, and rotor-bearing performance analyses for high-speed rotating systems.Support evaluations of airflow, heat transfer, and temperature distributions within turbomachinery components as part of thermal and structural assessments.Investigate complex interactions between mechanical, thermal, and rotor system behaviors.Collaborate with design, assembly, and testing teams to optimize component designs, assembly processes, and thermal management strategies.Assist in prototype and first-article testing, including integration, instrumentation setup, data collection, and analysis.Document technical results, share findings, and provide actionable insights to cross-functional teams.

Radiant Industries is on the lookout for a Lead Electrical Motor Design Engineer to spearhead the architecture, technical direction, and implementation of high-speed alternators and primary loop motors for our cutting-edge nuclear-driven power generation systems. This pivotal role will oversee the electric machine design function that is essential for the commercialization of the world's first mass-produced nuclear reactors.In this position, you will establish a technical vision for motor design while steering efforts in structural, thermal, and system integration. As a player-coach, you will actively engage in design work while mentoring a team of engineers to ensure the delivery of safe, reliable, and production-ready generator systems.This hands-on technical leadership position comes with substantial cross-functional impact.

Join BryceTech as a Senior Acquisition Lead and play a pivotal role in our mission to advance space technologies. In this leadership position, you will spearhead acquisition strategies that drive our growth and success in the competitive aerospace sector. Collaborate with cross-functional teams, manage key client relationships, and leverage market insights to identify and capture new business opportunities.

Join BryceTech as a Lead Software Engineer, where you will take charge of cutting-edge projects in the space industry. You will lead a talented team of engineers, driving innovation and excellence in software development. Your expertise will help shape the future of our space technology solutions.

Join Radiant Industries as a Lead Test Engineer for Power Generation Systems, where you will spearhead the strategy and execution of testing for our innovative power generation systems, encompassing turbomachinery, heat exchangers, controls, and primary cooling systems. This position is perfect for a hands-on technical leader who takes pride in developing test infrastructures, managing complex hardware operations, and mentoring engineering talent while being actively engaged in daily testing activities.In this role, you will take charge of the testing development for our high-speed machinery and build our testing facilities from the ground up. These infrastructures will be pivotal for rapid design iterations, focusing on evaluating vibration, performance, thermal behavior, and system reliability, ultimately facilitating a smooth transition into production acceptance testing. You will collaborate closely with mechanical design, analysis, manufacturing, and operations teams to validate and ensure that turbomachinery designs meet production standards.

About Radiant IndustriesRadiant Industries, headquartered in El Segundo, CA, is pioneering the development of the world’s first mass-produced, portable nuclear microreactors. Our flagship product, Kaleidos, is a revolutionary 1-megawatt microreactor designed for transportability and can operate continuously for up to five years without the need for refueling. This innovative solution aims to replace conventional diesel generators, providing essential energy support for hospitals, data centers, remote locations, and military bases. We leverage cutting-edge software engineering practices to deliver safe, factory-built microreactors utilizing established, high-quality materials. Established in 2020, Radiant Industries is gearing up to test its inaugural reactor at the Idaho National Laboratory next year, with initial customer deliveries set to commence in 2028.Position OverviewWe are looking for an accomplished Technical Lead DevOps Engineer to spearhead our software infrastructure, deployment, and automation initiatives. In this pivotal role, you will collaborate with teams across the organization, working closely with the software development team to design scalable, secure, and resilient DevOps practices, tools, and systems. The infrastructure you oversee, the pipelines you construct, and the analytical tools you develop will be integral to the design, operation, and analysis of our groundbreaking reactor, which represents a major advancement in nuclear technology over the past 50 years. This is a unique opportunity to establish a robust foundation for our production environment.Key Responsibilities:Architect, implement, and maintain infrastructure across AWS and on-premises Linux environments, ensuring high availability, security, and optimal performance for mission-critical systems.Oversee and enhance Kubernetes and Docker container orchestration to efficiently execute simulations, internal tools, and engineering applications at scale.Design, build, and optimize CI/CD pipelines using Git, Argo, and other automation tools to facilitate rapid and reliable software delivery across engineering teams.Develop internal tools that enhance build systems, testing frameworks, deployment automation, and developer environments.Create computational analysis tools for our digital twin platform, implementing automated profiling and monitoring to optimize high-performance computing workloads for reactor modeling.Implement and manage infrastructure-as-code practices using Terraform or similar tools to ensure reproducible, version-controlled infrastructure deployments.Establish and maintain observability, monitoring, and logging infrastructure to guarantee system reliability and performance.

Senior Manufacturing EngineerJoin Radiant Industries as a Senior Manufacturing Engineer, where you will collaborate with design engineers to revolutionize the production of intricate mechanisms and structures essential to our innovative microreactor technology. Your role will be critical in ensuring the reliability, safety, quality, and timely delivery of the Kaleidos demonstration unit, set for testing at the Idaho National Lab in 2026—marking the first new reactor design in over 50 years.Key Responsibilities:Oversee the manufacturing and inspection processes of vital components and assemblies within the Kaleidos microreactor.Collaborate with design engineers to create innovative production methods for complex mechanisms and structures.Develop, validate, and optimize manufacturing processes to fulfill all design and business requirements, including safety, quality, efficiency, and delivery timelines.Formulate and implement manufacturing specifications and fabrication instructions.Manage the manufacturing bill of materials (mBOM) for components and assemblies.Identify, evaluate, and establish partnerships with suppliers for component sourcing and fabrication.Identify, plan, and execute upgrades to capital equipment, machinery, and layout to adapt to evolving production needs.Lead initiatives that promote continuous improvements in manufacturing processes and product quality.

Join VardaSpace as a Senior Structures Engineer and be at the forefront of innovative aerospace solutions. In this pivotal role, you will lead the design and analysis of structural components for space vehicles, ensuring safety and performance in the demanding environment of space. You will collaborate with a passionate team of engineers and contribute to groundbreaking projects that push the boundaries of technology.

At Sift, we are pioneering the future of infrastructure for modern machines, transforming the way they are constructed, tested, and managed. Our innovative platform offers engineers unparalleled real-time observability over high-frequency telemetry, effectively eliminating bottlenecks and facilitating rapid, dependable development.Originating from our groundbreaking work at SpaceX on projects like Dragon, Falcon, Starlink, and Starship, Sift emerged from the need for advanced infrastructure to accommodate complex telemetry, debug flight systems, and ensure mission reliability. Our founding team, with expertise from SpaceX, Google, and Palantir, crafts solutions for mission-critical systems where precision and scalability are paramount.As a pivotal member of our engineering team, you will not only write code but also play a significant role in shaping the architecture, product direction, and culture of a company dedicated to addressing real engineering challenges. If you thrive on tackling intricate technical problems and aspire to build foundational systems that support complex machinery, we encourage you to apply.