Space Science & Space Physics Editors' Highlights

Extending the Envelope for Known Safe Locations in Space

When unattached electrons collide with spacecraft, the build-up of electric charge can cause malfunctions, but recent observations model near-Earth regions that are likely safe zones.

Source: Space Weather


Most operational spacecraft orbit Earth within 7 Earth radii. Over recent decades, a few research missions have sampled the plasma and energetic particle environment out to 20 Earth radii. From the limited (but growing) number of observations beyond geosynchronous orbit, Denton et al. [2019] have created an empirical model from the CLUSTER mission, a quartet of orbiting spacecraft with identical instruments.

This model supports prediction of electron flux in the energy range ~45 eV to ~325 keV, as a function of local-time and radial distance from the Earth near the equatorial plane. This is a key energy band associated with spacecraft charging. The model is parameterized by a geomagnetic activity index (Kp index) that ranges from 0 to 9. This new model supports international efforts in benchmarking extreme particles fluxes that may damage spacecraft or individual space-based instruments.

Citation: Denton, M. H., Taylor, M. G. G. T., Rodriguez, J. V., & Henderson, M. G. [2019]. Extension of an empirical electron flux model from 6 to 20 Earth radii using Cluster/RAPID observations. Space Weather, 17.

—Delores J. Knipp, Editor in Chief, Space Weather

Text © 2019. The authors. CC BY-NC-ND 3.0
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