Ionospheric Reentry of LEO Satellites Impacts GPS Accuracy: Teaching Introductory Plasma Physics to STEM K-12 Students

Students will learn that the ionosphere constitutes a plasma medium revealing neutrals, ions, and electrons. While the ionospheric plasma density is lower than atmospheric neutral gas density, plasma electrostatic charging can lead to the formation of plasma sheath and wake structures around a satellite. The total delay suffered by a radio wave propagating through the ionosphere depends both on the frequency of the radio wave and total electric count (TEC) between the transmitter and the receiver. And, disrupted radio wave propagation occurs due to changes in plasma and electron densities, formation of ionospheric plasma sheath on spacecraft reentry, increased interaction of electrons, ions, and molecules with radio waves. As of March 2023, 299 Starlink V1 (first generation) satellites re-entered the Earth’s ionosphere at a mass of approximately 300 kg each in a state of reentry burn. The resultant layer of re-entry particulate does not dissipate when the satellite demolishes. It stays stagnant in the upper atmosphere/ lower ionosphere for several years before decaying into the lower atmosphere. Satellites themselves may create a ionizing radiation zone with their reentry plasma dust to cause GPS/GNSS inaccuracies. This paper aims to explore approaches for their risk management.