Propulsion Engineer, Merlin Main Injector



hawthorne, ca, usa
Posted on Wednesday, March 29, 2023

SpaceX was founded under the belief that a future where humanity is out exploring the stars is fundamentally more exciting than one where we are not. Today, SpaceX is actively developing the technologies to make this possible, with the ultimate goal of enabling human life on Mars.


As a Merlin Development Engineer, you will own all aspects of ongoing Merlin Main Injector Assembly design, development, qualification, and production support. In this role, you will utilize your strong technical knowledge of metallic structures, elastomeric goods, mechanical and fluid fundamentals to ensure maximum reliability of the Merlin engine. You will fully integrate with the Merlin development, refurb, and flight operations teams as we fly commercial, national security, and crewed missions at a pace of 50+ flights per year.


  • Support build, test, and flight of Merlin Main Injector Assemblies for SpaceX’s Falcon 9 and Falcon Heavy reusable launch vehicles.
  • Generate accurate, precise, and thoughtfully-dimensioned CAD models and drawings, with appropriate Design for Manufacturing/Assembly (DFMA) considerations.
  • Review and/or update detailed structural analysis on all the Main Injector components/systems, and confirm that they meet the required standards for structural margin, fatigue life, etc.
  • Understand the detailed assembly and tolerance stack-ups required for assessing seal compression and extrusion for both static and dynamics seals.
  • Work with manufacturing engineers to ensure Main Injector and key sub-assemblies are manufactured correctly, efficiently and that all processes are value-added.
  • Lead ongoing design, manufacturing or reliability improvements to the Main Injector, and ensure the changes are properly qualified.
  • Work with teams developing other systems on the engine (combustion devices, valves, etc.) to have a deep understanding of the implications your part will have on adjacent/supporting systems.
  • Lead the resolution of issues encountered with the Main Injector during testing, flight operations or engine refurbishment in a timely fashion.
  • Support M1D and MVacD engine test teams for development, qualification, and production engines. This will involve travel to other SpaceX sites.


  • Bachelor’s degree in an engineering discipline
  • 2+ years of academic or professional experience related to combustion devices or rocket engine development


  • Bachelor’s degree in mechanical or aerospace engineering
  • Master’s degree in an engineering discipline
  • Strong fundamentals of structural mechanics, fatigue and fracture. Experience with stress analysis (ANSYS), fatigue and fracture calculations are strongly preferred.
  • Strong fluid flow and heat transfer fundamentals, specifically propellent injection elements/methods, combustion performance parameters, etc. Experience with CFD or fluent is not required, but value-added.
  • Hands-on experience with rocket engines, automotive engine design, dynamic or complex static fluid systems, etc.
  • Professional experience using Siemens NX (Unigraphics)
  • Experience with manufacturing processes such as CNC mill/lathe, welding, castings, additive, etc. Proficient with the fundamentals of Design for Manufacturing/Assembly (DFMA)
  • Great attitude in the face of extreme technical and schedule challenges
  • Experience at a nimble engineering organization or in a highly technical position that required a scrappy, entrepreneurial manner to accomplish tasks with tight time or budget constraints
  • Project experience or full professional engineering lifecycle experience (design trade, CAD design, prototyping, manufacturing, testing, qualification, production, reuse) is desired
  • Demonstrated track record of excellent academic and professional achievement
  • Excellent verbal and written communication skills, with both internal and external customers
  • Ability to deliver against an aggressive schedule, without sacrificing safety or reliability
  • Experience making risk evaluations and/or supporting root cause investigations.


  • Willingness to travel in support of testing (McGregor, TX), launching, and refurbishing (Cape Canaveral, FL and Vandenberg Space Force Base, CA) (~15% of year)
  • Willingness to work extended hours and weekends as needed to resolve critical technical issues


Pay Range:

Development Engineer/Level I: $95,000.00 - $115,000.00/per year

Development Engineer/Level II: $110,000.00 - $130,000.00/per year

Your actual level and base salary will be determined on a case-by-case basis and may vary based on the following considerations: job-related knowledge and skills, education, and experience.

Base salary is just one part of your total rewards package at SpaceX. You may also be eligible for long-term incentives, in the form of company stock, stock options, or long-term cash awards, as well as potential discretionary bonuses and the ability to purchase additional stock at a discount through an Employee Stock Purchase Plan. You will also receive access to comprehensive medical, vision, and dental coverage, access to a 401(k) retirement plan, short & long-term disability insurance, life insurance, paid parental leave, and various other discounts and perks. You may also accrue 3 weeks of paid vacation & will be eligible for 10 or more paid holidays per year. Exempt employees are eligible for 5 days of sick leave per year.


  • To conform to U.S. Government export regulations, applicant must be a (i) U.S. citizen or national, (ii) U.S. lawful, permanent resident (aka green card holder), (iii) Refugee under 8 U.S.C. § 1157, or (iv) Asylee under 8 U.S.C. § 1158, or be eligible to obtain the required authorizations from the U.S. Department of State. Learn more about the ITAR here.

SpaceX is an Equal Opportunity Employer; employment with SpaceX 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.

Applicants wishing to view a copy of SpaceX’s Affirmative Action Plan for veterans and individuals with disabilities, or applicants requiring reasonable accommodation to the application/interview process should notify the Human Resources Department at (310) 363-6000.