Please review these points carefully before applying:

• This application is exclusively for the software, controls, and electrical track.

• We provide both Internship and Co-op placements through this single posting.

Application Deadline: Thursday, April 9, 2026

About Marathon Fusion

Since our founding in 2023, we've developed fuel cycle technologies to deliver fusion energy more quickly with better economics. Marathon Fusion was founded by Adam Rutkowski, previously a Propulsion Engineer at SpaceX and PhD candidate in Plasma Physics at Princeton University, and Kyle Schiller, previously a Fellow in science policy at Schmidt Futures. We believed then, and now more than ever, that fusion is humanity's best pathway to abundant, clean and reliable energy.

We've secured over $10m in funding from the US Department of Energy and leading investors including 1517 Fund and Strong Atomics. We have letters of intent from leading fusion companies including Helion Energy, Commonwealth Fusion Systems, and Thea Energy.

We've built plasma centrifuges for isotope separation, superpermeable pumps for rapid fuel recycling in fusion power plants. We're on a quest to commercialize alchemy, accelerate the deployment of fusion energy, and open a new frontier in scientific discovery.

Culture at Marathon Fusion

We are a startup environment characterized by a need for focus, adaptability and prioritization in a shifting landscape. Thriving in this environment requires excellent proactive communication across roles and backgrounds, the ability to build and maintain trust between team members, and the willingness to learn and develop new skills on the job. We place particularly high weight on each team member's ability to be self-directed.

Technical Roles at Marathon Fusion

We are primarily interested in interns who are:

• Studying physics, but have meaningful hands-on experience in software and electronics as it relates to experiments.

• Studying computer engineering or a related field, with experience in controls or experiment design

• Studying electrical engineering or a related field, with experience in controls or experiment design

• Studying an engineering field or other technical field and have exceptional work-ethic, eagerness to learn, and autonomy.

Controls Intern Role

This track combines software development with hands-on electronics work and the integration of physical instrumentation. Successful candidates will work at the interface of hardware and control systems, writing software to interface directly with instruments

Core Responsibilities and Focus Areas

• Experimental Design: Conceptualizing, designing, and setting up experiments to test hardware and measure plasma properties.

• Hardware and Diagnostics: Designing, building, and characterizing electrical or optical measurement systems and experimental controls.

• Testing and Iteration: Executing experiments, analyzing data, and contributing to the design iteration of core technologies like the plasma centrifuge and metal foil pump.

• Software Design: Develop software to interface directly with laboratory instruments and hardware systems

  • Integrate with preexisting Marathon controls framework

  • Create new framework for new instruments

  • Further develop controls capability

Example Projects

Interns and Co-ops in this role have previously been involved in:

• Building python framework for asynchronous control of devices

• Building serial communication pipelines between instruments

• Full-stack web-based data acquisition dashboard / GUI

• Building electrical to optical PCB circuitboards

Preferred (But Not Required) Experience

We don't expect, but would be particularly excited about any candidates with experience in the following: Modbus, SCPI, PCB design, high power electronics, RF matching networks, plasma physics, LabView, NI DAQ Frameworks, Git, object oriented programming

For all roles, important soft skills include:

• Excellent written and oral communication

• Ability to think holistically about systems

• Capacity to learn new technical subjects quickly, collaborate cross-functionally, and consider problems from inter-disciplinary perspectives

• Organization and project management

• A high degree of conscientiousness and integrity

• Long-term vision while executing short-term goals

• Comfort with the inherent uncertainty of breakthrough technology

• Experimental mindset, ability to form and test hypotheses

Compensation

Undergraduate interns are paid $27.88/hour. More experienced interns can earn up to $43.27/hour depending on qualifications.

Marathon Fusion considers all qualified applicants equally for employment. We do not discriminate on the basis of race, color, national origin, ancestry, citizenship status, protected veteran status, religion, physical or mental disability, marital status, sex, sexual orientation, gender identity or expression, age, or any other basis protected by law, ordinance, or regulation. If you need assistance or an accommodation during the interview process, please let us know.