GOES-19, a NOAA geostationary weather satellite, triggered an electron flux alert at 09:20 UTC on 3 April after the 2 MeV integral electron flux exceeded 1,000 particle flux units 1. No news outlet has reported this specific alert in the context of Artemis II.
Elevated electron flux is a distinct hazard from the geomagnetic Kp index that measures storm intensity . High-energy electrons primarily threaten satellite electronics through deep dielectric charging, but for a crewed vehicle in translunar space they contribute to the cumulative radiation dose the crew absorbs. The two hazards, geomagnetic storm and elevated particle flux, are related but not identical.
NOAA SWPC forecasters remain in direct communication with NASA's Space Radiation Analysis Group (SRAG), the team responsible for crew dose management 2. Six HERA sensors throughout the cabin are feeding real-time data. Whether the current particle environment has meaningfully increased crew exposure beyond the baseline mission estimate is not publicly known.
Only the top 5% of solar particle events produce nausea-level radiation exposure 3. The current environment does not appear to approach that threshold. But the absence of public dose reporting means the margin of safety is, for now, a matter of institutional trust rather than verifiable data.
