Freelance Simulation Software Engineer Jobs in Texas

Are you passionate about human space exploration, understanding the origins of the universe, and working with a passionate and diverse team to make a difference? If you are, we need you!
We need your talent, teamwork, and energy to help us achieve great things that inspire people all over the globe. We need you to bring creative ideas and diverse backgrounds to help us envision, shape, and deliver systems that will enable the exploration of space while benefiting people here on Earth. We are excited about what we do, and we need you on our team as we take on exciting challenges for NASA's pursuits in deep space exploration. As NASA's largest engineering solutions provider working together with NASA at centers across the United States.
We have an exciting opportunity for a Simulation Software Engineer to join the JETSII Contract!
As an individual - contributor Simulation Software Engineer supporting a human spaceflight subsystem, you will design, develop, integrate, and test advanced simulation software used for spacecraft docking 6DOF motion subsystem analysis, verification, autonomy behaviors, and test environment integration. This role emphasizes hands - on development using NASA Trick , ROS/ROS2 , and high - fidelity physics based modeling tools that interface with flight software and motion systems.
Core Responsibilities
Simulation & Software Development

• Develop, maintain, and extend Space Vehical Systems simulations , docking subsystem models, and supporting software used for integrated test environments.
• Build interfaces, and supporting tools for simulations, integration labs, and autonomous behavior prototyping.
• Implement C/C++ and Python components in a Linux environment to support modeling, data exchange, and hardware - in - the - loop (HIL) integration.
• Integrate simulation products with those produced by other engineers, ensuring compatibility across the broader test and analysis toolchain.

Documentation & Collaboration

• Document simulation architecture, usage instructions, model assumptions, and interface details in Confluence .
• Maintain clear, well - commented code and Git documentation, including READMEs and versioning notes.
• Track and respond to development assignments using JIRA , providing transparent progress and timely updates.
• Author and revise software and simulation requirement specifications.

Testing, Analysis & Verification

• Configure and run simulation utilizing automated test frameworks, and data - logging pipelines.
• Ensure correct time - synchronization between simulation environments, control system software, and integrated dynamics models.
• Perform verification activities and generate test reports, demonstrations, or analysis summaries in formats such as Confluence pages or PowerPoint presentations.

Systems Understanding & Agile Execution

• Develop deep familiarity with spacecraft subsystem architecture, system interfaces, and modeling needs.
• Work effectively in a fast - paced Agile environment, coordinating with Integrated Product Teams and other software and system engineers.
• Communicate clearly, provide reliable technical updates, and maintain a strong customer - service attitude when supporting partner teams.

Other Duties
Requisition Qualifications

• Typically requires a minimum of a bachelor's degree in Engineering and normally possess 5- 10 years of related experience. License and certification may be required.

• Perform additional simulation or software - related tasks as assigned to support mission needs.
• Either BS + 6 years / MS + 2 years, or equivalent relevant engineering experience.
• Demonstrated experience developing or testing high - criticality or safety - critical software within an Integrated Product Team.
• Experience writing software requirements for safety - critical software.
• Hands - on experience with simulation testing tools, automated testing frameworks and timing synchronization between simulations and control systems.
• Proficiency in C/C++ (Linux) and scripting languages such as Python .
• Experience with Agile workflows and modern collaboration tools.

Requisitions Preferences:

• NASA Human Space Flight Software frameworks.
• Experience with simulation - based autonomy development or highly autonomous systems.
• Full - lifecycle software development experience, especially for simulation environments.
• Familiarity with Confluence, GitLab, JIRA, Teams, Slack, SharePoint, SQL, and QT.
• Background in safety - critical or flight - critical software development.
• Knowledge of NASA software engineering and systems development standards.

Why Join Our Team?
In addition to exciting career opportunities, we also have:

• Excellent personal and professional career growth
• 9/80 work schedule (every other Friday off), when applicable
• Onsite cafeteria (breakfast & lunch)
• Much, much more!

For more information on our partnership with NASA at Johnson Space Center (JSC), please visit www.wehavespaceforyou.com

• Proof of U.S. Citizenship or US Permanent Residency may be a requirement for this position.
• Must be able to complete a U.S. government background investigation.
• Management has the prerogative to select at any level for which the position is advertised.

Essential Functions
Work Environment
Generally, an office environment, but can involve inside or outside work depending on task.
Physical Requirements
Work may involve sitting or standing for extended periods (90% of time). May require lifting and carrying up to 25 lbs. (5% of time).
Equipment and Machines
Standard office equipment (PC, telephone, printer, etc.).
Attendance
Regular attendance in accordance with established work schedule is critical. Ability to work outside normal schedule and adjust schedule to meet peak periods and surge requirements.
Other Essential Functions
Professional behavior that enhances productivity and promotes teamwork and cooperation. Grooming and dress must be appropriate for the position and must not impose a safety risk/hazard to the employee or others.
#JETS #JETSII
Compensation Details:
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The compensation range or hourly rate listed for this position is provided as a good-faith estimate of what the company intends to offer for this role at the time this posting was issued. Actual compensation may vary based on factors such as job responsibilities, education, experience, skills, internal equity, market data, applicable collective bargaining agreements, and relevant laws.
Benefits Overview:
Our health and welfare benefits are designed to support you and your priorities. Offerings include:

• Health, dental, and vision insurance
• Paid time off and holidays
• Retirement benefits (including 401(k) matching)
• Educational reimbursement
• Parental leave
• Employee stock purchase plan
• Tax-saving options
• Disability and life insurance
• Pet insurance

Note: Benefits may vary based on employment type, location, and applicable agreements. Positions governed by a Collective Bargaining Agreement (CBA), the McNamara-O'Hara Service Contract Act (SCA), or other employment contracts may include different provisions/benefits.
Original Posting:
06/10/2026 - Until Filled
Amentum anticipates this job requisition will remain open for at least three days, with a closing date no earlier than three days after the original posting. This timeline may change based on business needs.
Amentum is proud to be an Equal Opportunity Employer. Our hiring practices provide equal opportunity for employment without regard to race, sex, sexual orientation, pregnancy (including pregnancy, childbirth, breastfeeding, or medical conditions related to pregnancy, childbirth, or breastfeeding), age, ancestry, United States military or veteran status, color, religion, creed, marital or domestic partner status, medical condition, genetic information, national origin, citizenship status, low-income status, or mental or physical disability so long as the essential functions of the job can be performed with or without reasonable accommodation, or any other protected category under federal, state, or local law. Learn more about your rights under Federal laws and supplemental language at Labor Laws Posters.