The HiLat satellite mission


  • E. J. Fremouw,

  • H. C. Carlson,

  • T. A. Potemra,

  • P. F. Bythrow,

  • C. L. Rino,

  • J. F. Vickrey,

  • R. L. Livingston,

  • R. E. Huffman,

  • C.-I. Meng,

  • D. A. Hardy,

  • F. J. Rich,

  • R. A. Heelis,

  • W. B. Hanson,

  • L. A. Wittwer


On June 27, 1983, USAF satellite P83-1 was launched from Vandenberg Air Force Base carrying the five ionospheric-effects and diagnostic payloads of DNA's HiLat satellite mission. A Scout launch vehicle placed the satellite in an 800-km circular orbit at an inclination of 82°. The HiLat experiments are as follows: (1) a VHF/UHF/L band coherent radio beacon for observing complex-signal scintillation and total electron content; (2) a three-instrument cold-plasma package for measuring number density and temperature, their spatial fluctuations, and plasma convection velocity and its fluctuations; (3) an electron spectrometer for detection of precipitating and upwelling electrons with energies between 20 eV and 20 keV; (4) a three-axis magnetometer; and (5) an optical assembly for imagery and spectrophotometry in the vacuum-ultraviolet spectrum and for photometry at two visual wavelengths. With the exception of partial launch damage to the electron sensor (Langmuire probe) in the coldplasma package, all payloads initially operated as designed. After approximately 40 orbits of data collection, however, the imaging spectrophotometer failed. In spite of this failure, the optical instrument proved the concept of imaging the aurora, at vacuum-ultraviolet wavelengths, under conditions of full sunlight. Its visual-wavelength photometers continue to perform well, as do the other four HiLat payloads. This paper presents early observations from HiLat.