Simultaneous Observations of Solar-Flare Electron Spectra in Interplanetary Space and Within Earth's Magnetosphere

Magnetic electron spectrometers on satellites OGO-V and OV1-19 were used to make simultaneous measurements in interplanetary space and over the polar caps during the intense solar-particle event of April 1969. The absolute intensities and energy spectra measured on the two satellites tracked within experimental error for the entire history of the event. The results are examined in terms of the "open" and "closed" models of Earth's magnetosphere.