The IMP-8 satellite is the last in a family of ten Interplanetary
Monitoring Platforms. IMP-8 was launched on 26 October
1973 into a nearly circular orbit about the Earth at a radius of about 35 Earth
radii. It spends 60% or more of each 12-day orbit in the solar wind, and the
rest of its time in the magnetosheath and magnetosphere. IMP-8 is a
spin-stabilized spacecraft, with its spin vector nearly perpendicular to the
ecliptic plane, and a spin rate of 24 rpm.
The Charged Particle Measurements Experiment
(CPME) and the Energetic Particle Experiment
(EPE) on IMP-8 have operated successfully for 28
years and have generated a wealth of high-quality data that have led to new
discoveries and have resulted in hundreds of publications. Both the CPME
and EPE instruments continued to perform without problems until IMP-8
operations were terminated by NASA at the end of October 2001
(see Mission Overview Plot ).
These pages describe both the CPME and EPE Instruments,
and provide text-formatted data files containing energetic ion
and electron count rates and fluxes that cover a wide variety of
ion species, energy ranges, angular distributions,
and time resolutions.
For further information regarding the CPME and EPE data contact:
Dr. R. B. Decker (e-mail:
robert.decker@jhuapl.edu)
Dr. D. G Mitchell (e-mail:
don.mitchell@jhuapl.edu)
Both at: The Johns Hopkins University Applied Physics Laboratory,
11100 Johns Hopkins Road, Laurel, Maryland, 20723-6099, U.S.A.