ESA is planning to launch in December 1993 a solid earth mission satellite, primary equipped with a satellite gradiometer to monitor the earth's gravity field. The program is called Aristoteles. A phase-A study is being carried out during 1988. Probably, a non-dragfree satellite in 200 km altitude will be recommended. Expected accuracy will be better than 5 mgal and 1 · 1° resolution. Aristoteles will have great impact on geodesy, geodynamics, oceanography, and satellite orbit control.