What are the responsibilities and job description for the Propulsion Engineer (Fluids) position at Apex - Spacecraft Manufacturing?
Spacecraft represent the most pressing unmet need across the entire aerospace industry. As more launch vehicles come online and the cost to orbit decreases, more companies launching payloads to space continue to emerge.
For the first time in history, this influx of payload companies combined with reduced launch costs has resulted in a massive increase in need for commercial spacecraft platforms, known as satellite buses. These buses hold the payloads of our customers and are flown on launch vehicles.
Apex manufactures these satellite buses at scale using a combination of software, vertical integration, and hardware that is designed for manufacturing. Our spacecraft enable the future of society: ranging from earth observation to communications and more.
We’d love for you to join us on our mission of providing humankind access to the galaxy beyond our planet.
About The Role
As a key member of the Propulsion Team, you will design, develop, and own the propulsion system components that enable Apex spacecraft to perform orbital maneuvers. You will be responsible for building critical systems that operate reliably 24/7, ensuring that users can seamlessly ignite Apex propulsion systems.
In this role, you will work closely with internal teams and external parties (such as range safety, DOT, and launch providers), aligning your solutions with company objectives and system requirements. We are seeking motivated engineers who are eager to solve complex problems with a focus on practicality and scalability, and who thrive in a dynamic, fast-paced environment.
Key Responsibilities
Apex believes in creating a work environment that you look forward to embracing every day. Our employees love working at Apex, and we want you to love it too. We're a fast-growing startup backed by $200M in Series C funding, and we invest heavily in our people from day one.
What We Offer
Equal Opportunity Employer
Apex Technology, Inc. is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. Candidates and employees are always evaluated based on merit, qualifications, and performance. We will never discriminate on the basis of race, color, 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.
Compensation Range: $115K - $145K
For the first time in history, this influx of payload companies combined with reduced launch costs has resulted in a massive increase in need for commercial spacecraft platforms, known as satellite buses. These buses hold the payloads of our customers and are flown on launch vehicles.
Apex manufactures these satellite buses at scale using a combination of software, vertical integration, and hardware that is designed for manufacturing. Our spacecraft enable the future of society: ranging from earth observation to communications and more.
We’d love for you to join us on our mission of providing humankind access to the galaxy beyond our planet.
About The Role
As a key member of the Propulsion Team, you will design, develop, and own the propulsion system components that enable Apex spacecraft to perform orbital maneuvers. You will be responsible for building critical systems that operate reliably 24/7, ensuring that users can seamlessly ignite Apex propulsion systems.
In this role, you will work closely with internal teams and external parties (such as range safety, DOT, and launch providers), aligning your solutions with company objectives and system requirements. We are seeking motivated engineers who are eager to solve complex problems with a focus on practicality and scalability, and who thrive in a dynamic, fast-paced environment.
Key Responsibilities
- Fluids System Design
- Design and analyze spacecraft and ground support fluid systems (e.g. propellant, pressurant, pneumatics).
- Develop P&IDs, and component specs.
- Size valves, lines, regulators, filters, and pressure vessels based on mission requirements.
- Range Safety & Launch Readiness
- Interface with launch range authorities to ensure fluid systems meet all safety and compliance requirements.
- Develop fault-tolerant systems and safety interlocks that comply with range standards (e.g., SSCMAN 91-710 or equivalent).
- Ground Tooling & Operations
- Design, build, and test ground support equipment (GSE) for filling, draining, and servicing spacecraft fluids.
- Create procedures and tooling to support safe and efficient pre-launch operations.
- Support integration and launch campaigns on-site.
- Manufacturing & Scalability
- Design fluid components and assemblies for mass manufacturing (e.g., modular designs, standardized fittings, DFM/DFA principles).
- Collaborate with manufacturing and supply chain teams to reduce cost and lead times.
- Testing & Validation
- Own end-to-end test plans for fluid systems—pressure, leak, flow, cryo, and functional tests.
- Support hardware bring-up, validation, and anomaly resolution during development and on the pad.
- Fluid System Design
- Understanding of fluid dynamics, thermodynamics, and heat transfer
- Proficiency in piping and instrumentation diagrams (P&IDs)
- Component selection and sizing: valves, regulators, filters, pressure vessels, pumps, tanks, orifices
- Design of high-pressure propellant systems
- System Analysis & Modeling
- Pressure drop, flow rate, and line sizing calculations
- Transient analysis (e.g., water hammer, blowdown)
- CAD & Mechanical Design
- Proficiency in 3D CAD tools:
- Design of mechanical interfaces, mounting brackets, fluid panels, and routing systems
- Design for assembly, testing, and transportability
- Geometric Dimensioning & Tolerancing (GD&T) knowledge
- Manufacturing & Tooling
- Design for Manufacturability (DFM) and Assembly (DFA)
- Knowledge of welding (TIG, orbital), tube bending, machining, and additive manufacturing
- Familiarity with standard aerospace fittings: AN, VCO, VCR, Swagelok, quick disconnects, etc.
- Tooling for fill/drain operations, including connectors, quick disconnects, and valve control systems
- Testing & Operations
- Leak testing methods: pressure decay, helium leak testing (sniffer, mass spec, etc)
- Hydrostatic and pneumatic testing
- Familiarity with cleaning and compatibility for propellants
- Experience writing test plans, procedures, and executing test campaigns
- U.S. Person status is required as this position needs to access export-controlled data.
- 5 years of total experience
- Bachelor’s degree in Mechanical Engineering or equivalent.
- Possess excellent interpersonal skills, able to work effectively within an organization and convey decisions, direction, and conclusions in a manner meaningful to multiple audiences.
- Self-motivated and able to work independently with minimal supervision, as well as in a team-oriented environment.
- Strong attention to detail, organizational skills, and the ability to manage multiple priorities and meet project deadlines.
Apex believes in creating a work environment that you look forward to embracing every day. Our employees love working at Apex, and we want you to love it too. We're a fast-growing startup backed by $200M in Series C funding, and we invest heavily in our people from day one.
What We Offer
- Shared upside: Receive equity in Apex, letting you benefit from the work you create
- Best-in-class healthcare: 100% company-paid medical, dental, and vision for you and your dependents, plus $100k life insurance at no cost
- Comprehensive PTO package to reset and recharge - starting at 15 days vacation, growing to 20 days annually, plus 10 paid holidays
- Competitive 401(k) plan with generous matching - 100% match on first 3%, 50% on next 2%
- 8 weeks paid parental leave plus childcare reimbursement up to $350/day for work-related travel
- Daily catered lunch and unlimited snacks to keep you fueled throughout the day
- Vibrant community: Monthly office BBQs, pickleball tournaments, run club, and social gatherings for you and your family
- Your dream desk setup and all the tools you need to be your most productive self
- World-class Playa Vista office with EV chargers, with the benefit of in-person collaboration with amazing coworkers and flexibility to integrate work and life
- Real impact opportunity: Work alongside experts from aerospace, new space, and other cutting-edge industries to make a lasting difference
Equal Opportunity Employer
Apex Technology, Inc. is an Equal Opportunity Employer. We celebrate diversity and are committed to creating an inclusive environment for all employees. Candidates and employees are always evaluated based on merit, qualifications, and performance. We will never discriminate on the basis of race, color, 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.
Compensation Range: $115K - $145K
Salary : $115,000 - $145,000
