NASA's IMP-8 (Explorer 50) was launched on 26 October 1973 to study cosmic rays, energetic solar particles, plasma, and electric and magnetic fields in interplanetary space, the magnetotail, and magnetospheric boundaries. Operating in a near-circular orbit about 35 Earth radii from Earth, it provided long-duration solar-wind measurements and a one-AU baseline for deep-space Voyager and Ulysses studies.
Alerts for directly linked future launches and major activity.