ESA Science & Technology30-Jun-2005 16:32:52

Background Science

Radio Science

Two scientific investigations have been carried out using the Ulysses spacecraft's dual-frequency (X- and S-band) radio communications link with the Earth:  

  • SCE (Solar Coronal-Sounding Experiment)  
  • GWE (Gravitational Wave Experiment)

SCE (Solar Coronal-Sounding Experiment)  
The main goal of the SCE radio science experiment was to measure the electron content (column density), and its variations, of the near-Sun corona using radio sounding techniques. This experiment was conducted on two occasions, during the first solar conjunction (C1) of the Ulysses mission in the summer of 1991, and again during the fourth solar conjunction (C4) in the winter of 1995. In addition, radio sounding of the Io Plasma Torus was carried out during the Jupiter fly-by in 1992.

GWE (Gravitational Wave Experiment)
The GWE was an attempt to detect, for the first time, low-frequency (mHz) gravitational waves crossing the solar system. Potential sources of such gravitational waves include astrophysical objects such as binary black holes, supernovae, quasars, and active galactic nuclei. The data did not lead to a positive identification of gravitational waves.

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