Space RHA grew out of a recurring problem in radiation-effects work: engineers keep rebuilding the same calculations and searching for the same data.
The inputs and methods are spread across standards, papers, test reports, facility documentation, institutional tools, and spreadsheets. Applying them also depends on experience that is not always captured in those sources.
Space RHA puts some of that material in one place.
The site focuses on practical radiation hardness assurance: single-event effects, total ionizing dose, displacement damage, radiation test planning, device evaluation, and mission-level risk assessment.
The tools are intended to make routine calculations faster and more reproducible without hiding the assumptions underneath them. Where practical, the methodology, source data, limitations, and references are published alongside the calculation so an engineer can decide whether the result is appropriate for the problem at hand.
Space RHA also collects radiation test data and provides a place to discuss results and methodology. Radiation effects remains a small field, and a significant amount of useful information never becomes a formal publication.
The tools are free to use and require no account.
Space RHA is run by Greg Allen, a radiation effects engineer, through Space RHA LLC in Pasadena, California. The tools come from the parts, test and analysis side of flight projects: the SEE test plans, the rate calculations, the derating arguments and the parts review board questions that recur on every mission. Several of the methods implemented here are the published work of colleagues in the field and are credited on the relevant pages. The implementation is written with an AI model, as described next; the choice of what to build, the review, and any errors that survive it are Greg's.
The code and the text on this site, the tools, the guides, the methodology sections and the validation harnesses, are written with Claude, Anthropic's AI model. This is disclosed here and in the footer of every page. Greg decides what to build and why, supplies the papers, standards and data sets, sets the rules (what may be published and what may not, which conventions to use, what a page must and must not claim), reads the result and publishes it. Claude writes the code and the prose from the sources named on each page, and writes the harness that checks each engine against the paper's own numbers. The physics and statistics come from the published sources credited on each page. Greg is responsible for reviewing the implementation and the published content.
Verification and review. Each engine is compared with the numbers in the paper it implements, and those records are published where they exist (the alpha law tool's implementation checks are the first). Those records check the code against the paper; whether a model predicts real rates is a separate question, and for the alpha law on FinFETs it is still open. Numerical checks cannot establish that every explanation or modeling assumption is appropriate. Technical review is also needed. The pages therefore include their assumptions, limitations, and methodology. Reader corrections are acted on and acknowledged, and colleagues who have reviewed a page are named on it. If a statement here is wrong, say so through the contact page or the forum; reader feedback helps improve the site.
Data access and use of the tools. The model has no access to proprietary or export controlled data; the compiled data sets it works from are the public ones described on each page, and trends drawn from other data are anonymized and labeled as such. No AI model runs when you use a tool: every calculator on this site is ordinary JavaScript executed in your browser, deterministic, with its source readable in the page.
Found a mistake? Have data that could improve one of the models? Disagree with an assumption? Have an RHA calculation that would be useful to add? Send a note or bring it to the forum.
