RADIATION DATA
What Artemis I sensors actually measured vs what Apollo crews reportedly experienced. Numbers from NASA technical publications and mission reports. No editorializing — just the data.
MEASURED RADIATION DOSES
Artemis I — MARE Experiment
Inside Orion (unshielded phantom)
~60 mSv
25.5 days | ~2.4 mSv/day
Matroshka AstroRad Radiation Experiment — anthropomorphic phantom torso with 1,400+ passive dosimeters. Measured deep space radiation environment during transit and lunar flyby.
Artemis I — MARE (shielded)
Inside Orion (AstroRad vest)
~40 mSv
25.5 days | ~1.6 mSv/day
Second phantom wore the AstroRad radiation protection vest. ~33% dose reduction compared to unshielded phantom.
Artemis I — RAM sensors
Orion interior various
50-150 mSv range
25.5 days | Varies by position
Radiation Area Monitor passive dosimeters placed throughout the crew module. Dose varied significantly based on position relative to shielding.
Apollo missions (reported)
Inside CM/LM
1.8-11.4 mSv
6-12 days | 0.3-1.3 mSv/day
NASA-reported doses for Apollo 7-17. Apollo 14 reported the highest skin dose at 11.4 mSv. These numbers are remarkably low for missions passing through the Van Allen belts.
ISS (6-month stay)
Low Earth Orbit (~400 km)
~80-160 mSv
~180 days | 0.5-0.9 mSv/day
ISS orbits below the inner Van Allen belt. Partial shielding from Earth's magnetic field. Higher doses during solar particle events.
Van Allen Belts (peak)
Inner belt (~3,000 km)
Up to 25+ mSv/hour
Transit time | 25,000+ mSv/day at peak
The inner Van Allen belt contains trapped protons with energies up to 100 MeV. Peak flux zone is ~1.5-2 Earth radii. Apollo trajectories reportedly passed through in ~30 minutes each way.
QUESTIONS THE DATA RAISES
Apollo crews reportedly received 1.8-11.4 mSv passing through the Van Allen belts. Artemis I (uncrewed) measured ~60 mSv over 25 days in deep space — roughly 2.4 mSv per day. How did Apollo crews receive less total dose in missions that spent longer in more intense radiation zones?
Apollo transited the Van Allen belts twice (out and back). The inner belt peak can deliver 25+ mSv per hour. A 30-minute transit through the peak would deliver ~12 mSv per pass, or ~25 mSv round trip — more than most full Apollo mission totals.
Why was the MARE experiment on Artemis I the first detailed radiation measurement in deep space, 54 years after Apollo?
NASA describes MARE as providing "the most detailed radiation measurements ever taken in deep space." If Apollo crews successfully transited these environments, the radiation environment should have been well-characterized decades ago.
Artemis I Orion flew a higher-altitude trajectory through the Van Allen belts to minimize radiation exposure. If Apollo solved this problem in 1969, why does Artemis need to avoid the belts?
NASA mission planners specifically designed Artemis trajectories to minimize Van Allen belt transit time and peak exposure. This implies the belts remain a significant engineering concern — which raises questions about how Apollo handled them with far less shielding.
SOURCES
ARTEMIS TRACKER — NIXFRED.TECH