On the Human Health and Performance Contract we are at the forefront of safeguarding astronaut health, ensuring human performance, and advancing technologies for human space exploration. We are seeking a Senior Decision Scientist/Engineer to support our Biomedical and Environmental Research Department at the NASA Johnson Space Center (JSC) in Houston, TX.

In this role you will support research and operational decision-making for NASA’s Planetary Protection efforts. This role focuses on applying Bayesian decision theory, quantitative risk assessment, and advanced modeling methods to evaluate backward contamination risks for human and robotic exploration missions. You will contribute to safeguarding Earth and other planetary bodies as human and robotic exploration expands across the solar system. This is a unique opportunity to apply advanced statistical and analytical expertise to real‑world challenges in space exploration, planetary science, and human spaceflight risk management. Your work will help define and guide the actions necessary to ensure the safety of Earth’s biosphere and humankind.

Must be U.S. Citizen or U.S. Permanent Resident due to length of investigation for non-U.S. persons.

Primary Responsibilities:

Planetary Protection Analysis & Modeling

• Develop and implement Bayesian decision theory frameworks to support risk-based decision making.
• Construct probabilistic and statistical models for contamination likelihood, microbial transfer, and system-level uncertainties.
• Inform optimal sample-testing strategies to determine containment needs and evaluate risks associated with Mars samples returned to Earth (backwards planetary protection).
• Conduct uncertainty quantification, sensitivity analysis, and scenario modeling for exploration missions.

Data Management & Technical Modeling

• Clean, integrate, and validate multidisciplinary datasets (biological, environmental, engineering, and operational).
• Build predictive models to evaluate system performance and biosafety pathways.
• Apply computational tools such as R, Python, Stan, C, and other modeling environments.
• Develop integrated dashboards that synthesize current risk-assessment knowledge based on available data.

Regulatory & Compliance

• Ensure adherence to NASA, COSPAR, and internal Planetary Protection standards.
• Prepare documentation aligned with IRB, FDA, and GLP requirements when applicable.
• Support audit readiness and mission reviews through clear and complete technical documentation.

Collaboration & Communication

• Work closely with life scientists, mission planners, engineers, and flight operations personnel.
• Present model results, assumptions, and recommendations using clear visualizations and technical reports.
• Translate complex statistical or risk-based concepts into actionable operational guidance.

Your Qualifications:

• Master’s or Ph.D. in Decision Theory, Statistics, Biostatistics, Applied Mathematics, Computer Science, AI/ML, Data Science, or related field.
• Demonstrated experience with Bayesian inference and Bayesian decision theory.
• Proficiency with statistical and modeling tools such as R, Python, Stan, SAS, or equivalent. S
• Strong foundation in probabilistic modeling, experimental design, and risk assessment.

Desired Skills:

• Research or operational experience in planetary protection, astrobiology, microbial risk assessment, or aerospace health.
• Familiarity with COSPAR Planetary Protection guidelines.
• Experience with machine learning methods and advanced statistical modeling frameworks.
• Prior support of NASA programs or spaceflight-related research.

Core Competencies

• Analytical rigor and strong quantitative problem-solving skills.
• Ability to communicate complex technical topics to diverse audiences.
• Collaborative mindset for interdisciplinary projects.
• Detail-oriented approach to compliance documentation, and modeling

What to Expect

This position is office-based at JSC.

If you're looking for comfort, keep scrolling. At Leidos, we outthink, outbuild, and outpace the status quo — because the mission demands it. We're not hiring followers. We're recruiting the ones who disrupt, provoke, and refuse to fail. Step 10 is ancient history. We're already at step 30 — and moving faster than anyone else dares.

Original Posting:

April 10, 2026

Pay Range:

Pay Range $131,300.00 - $237,350.00

The Leidos pay range for this job level is a general guideline only and not a guarantee of compensation or salary. Additional factors considered in extending an offer include (but are not limited to) responsibilities of the job, education, experience, knowledge, skills, and abilities, as well as internal equity, alignment with market data, applicable bargaining agreement (if any), or other law.