Project SEE (Satellite Energy Exchange): an international effort to develop a space-based mission for precise measurements of gravitation

Project SEE (Satellite Energy Exchange) is an international effort to devel op a space-based mission for precise measurements of gravitation. Gravity i s the missing link in unification theory. Because of the unique paucity of knowledge about this, the weakest of all known forces, and because gravity must have a key role in any unification theory, many aspects of gravity nee d to be understood in greater depth. A SEE mission would extend our knowled ge of a number of gravitational parameters and effects, which are needed to test unification theories and various modern theories of gravity. SEE is a comprehensive gravitation experiment. A SEE mission would test for violations of the equivalence principle (EP), both by inverse-square-law ( ISL) violations and by composition dependence (CD), both at ranges of the o rder of metres and at ranges on the order of R-E. A SEE mission would also determine the gravitational constant G, test for time variation of G, and p ossibly test for post-Einsteinian orbital resonances. The potential finding of a nea-zero time variation of G is perhaps the most important aspect of SEE. A SEE mission will also involve a search for new particles with very l ow masses, since any evidence of violations of the EP would be analysed in terms of a putative new Yukawa-like particle. Thus, SEE does not merely test for violations of general relativity (GR); S EE is a next-generation gravity mission.