Don Helton

Don Helton

Nuclear Flight Safety Officer

Learn more about Nuclear Flight Safety Officer Don Helton.

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Points of Contact

Points of Contact

For details on contacting a Nuclear Flight Safety Point of Contact (PoC), click below.

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SATERN Courses
Introduction to Nuclear Flight Safety for SMA SMA-STL-WBT-403

This course is designed to provide NASA personnel with an overview of Nuclear Flight Safety and to increase knowledge across the programmatic, mission support and Technical Authority, with a focus on Safety and Mission Assurance personnel. 

SMA-STL-WBT-403 Details Launch SATERN
Radiation Safety Resources

In addition to space nuclear systems, NASA personnel use small quantities of radioactive material to accomplish the agency’s mission, and in some cases, this includes using this material in high-altitude flights and spaceflights. The resources immediately below highlight the importance of radiation protection and diligence when using these sources to provide familiarity or a refresher. More detailed information is available elsewhere on this page, on the NASA Safety Center’s Radiation Safety site linked at the bottom of this page, and on OCHMO’s Health Physics page .
Think Safety: Radioactive Material Awareness
Remember the Risks: Radioactive Material Awareness Video
60-Second Safety: Reduce Radiation Exposure
Knowledge Byte: More to Know About MAMS

Policy and Guidance

NASA and Interagency

Policy Title Buttons Buttons
NPR 8715.26
Nuclear Flight Safety
NPR 8715.26 Details  See NPR 8715.26
INSRB Trial Use Playbook Interagency Nuclear Safety Review Board (INSRB) Playbook, approved January 20, 2023      Playbook Details See Playbook
Provide Feedback
INSRB Charter Charter of the Interagency Nuclear Safety Review Board, approved June 14, 2022              Charter Details See Charter
Provide Feedback
Categorial Relief Memo 2
Categorical Relief for Launches and Reentries Involving an A2 Mission Multiple Less Than 0.001 (2023 Update)
Memo Details See Memo 
NASA-HDBK-8715.26 Information and Best Practices Related to NASA Nuclear Flight Safety for Space Flights Involving Space Nuclear Systems  Handbook Details  See NASA-HDBK-8715.26

Federal Guidance on Launch of Spacecraft Containing Space Nuclear Systems

The 2019 Presidential Memorandum on Launch of Spacecraft Containing Space Nuclear Systems (NSPM-20) revises the process for launches of spacecraft containing space nuclear systems, including Radioisotope Power Systems, Radioisotope Heater Units , and Fission Reactors. It states, “The ability to use space nuclear systems safely and sustainably is vital to maintaining and advancing United States dominance and strategic leadership in space. For United States launches of space nuclear systems, the Federal Government must ensure a rigorous, risk informed safety analysis and launch authorization process.” The memorandum covers both federal government launches and commercial launches and, among other things, it establishes a new set of safety guidelines, a revised launch authorization process and a standing Interagency Review Board.

The 2020 Space Policy Directive-6 outlines a government-wide strategy for space nuclear power and propulsion activities and provides greater clarity on how NASA’s programmatic activities, as well as those of its inter-governmental, commercial and international partners, fit in to that overall strategy. It also codifies the expectations for safe disposal of Earth-orbiting spacecraft that use a space nuclear system.