A suite of free, interactive tools for exploring space radiation environments from Low Earth Orbit (LEO) to Geostationary Orbit (GEO). Each tool generates heatmaps of orbital altitude vs inclination, allowing rapid visual assessment of radiation risks across mission profiles. These tools are intended as visual guides only and should not replace detailed analysis.
Total Ionizing Dose (TID) Tool
→The TID tool calculates radiation environment requirements for spacecraft missions across different orbital regimes. It uses a "fix two, solve one" approach where you specify two of three parameters and the tool calculates the third across circular orbits from LEO to GEO and lunar orbits.
Input Parameters — choose two fixed parameters and one variable to calculate:
Shielding Thickness — Find required protection for given TID tolerance and lifetime. Equivalent aluminum thickness protecting components.
Survival TID — Find required part radiation hardness for given shielding and lifetime. Radiation tolerance required for parts.
Max Mission Lifetime — Find the mission duration limit for given shielding and TID tolerance. Time on orbit.
Recommended parameter ranges:
Shielding: 3–5 mm (default: 4 mm if unknown) · TID tolerance: 5–100 kRad (default: 5 kRad if unknown) · Lifetime: 3–15 years
Note: Values are capped for readability (shielding >99 mm, TID >999 kRad, lifetime >99 years displayed at maximum). Only circular orbits are shown.
Single Event Effects (SEE) Tool
→The Petersen Figure of Merit (FOM) method has been used to plot heat maps of altitude vs inclination with colour indicating Single Event Effect (SEE) rates. Petersen developed a Figure of Merit (FOM) as a useful parameter to describe part upset sensitivity, and to approximate upset rates. The approach correlates ground based test data with on-orbit event rates, providing a relation that gives order of magnitude event rates for different orbits.
Four types of test data can be used:
Proton test data — A single data point is needed: the limiting cross-section (events per proton per cm²) at 100–200 MeV protons.
Heavy ion test data — Full Weibull fit parameters for a heavy ion test, where event cross-sections are taken at multiple Linear Energy Transfers (LET).
On-orbit event rates — Added by Space Radiation Services as a way to correlate on-orbit data to different orbits.
Manual FOM entry — For users with their own calculated FOM, or for proton SEL.
Limitations:
The FOM method is targeted at soft error rates and should not be used for destructive SEE analysis. This approach is not accurate and should only be used to give order-of-magnitude results. All correlated data is from before 1998 and may not be as accurate for modern electronics. There is an artificial low spot just over 7000 km due to limited data in the 1998 paper. When using proton cross-section data, note that some events do not occur with protons.
* E. L Petersen, "The SEU Figure of Merit and Proton Upset Rate Calculations," IEEE TRANSACTIONS ON NUCLEAR SCIENCE, VOL. 45, NO. 6, DECEMBER 1998
Atomic Oxygen (AO) Tool
→Calculates atomic oxygen densities, fluxes, and erosion rates across LEO orbits. Presents results for two solar conditions — solar mean (F10.7 = 145, Ap = 15) and solar max (F10.7 = 250, Ap = 45) — reflecting how higher solar activity increases AO density in LEO.
AO Density & Flux — Density and ram-direction flux at your selected orbit under mean and max solar conditions.
Erosion Rate (μm/year) — Input a material erosion yield (cm³/atom) to get erosion rates. Published NASA MISSE data is recommended as a starting point.
Internal Charging Tool
→Calculates internal charging risk and shielding requirements from LEO to GEO, based on charging current (A/cm²) on a planar surface after aluminium shielding. Uses the NASA-HDBK-4002B threshold of 1 × 10⁻¹³ A/cm² for pass/fail visualisation.
Minimum required shielding — Set an acceptable current threshold to find the minimum aluminium shielding required across all orbits.
Charging current — Select a shielding level to see the internal charging current at each orbit, with green/red pass/fail colouring.
Note: This tool has not been benchmarked. Recommended threshold: 1×10⁻¹³ A/cm² (NASA-HDBK-4002B).
Need more detailed analysis?
Space Radiation Services offers professional radiation analysis and consulting.