HEOS-1

HEOS-1 was launched on December 5, 1968 and was operational until 1975, a period of high solar activity.

It determined the magnetic field and the proton and electron distribution in the near earth space.

MPE was involved with the ion cloud experiment: A container weighing 8 kg and filled with Barium and Copper oxide was ejected from the satellite and produced a ion cloud in a distance of 50 km from the satellite.