THE GALILEO GALILEI SMALL-SATELLITE MISSION WITH FEEP THRUSTERS (GG)

The Equivalence Principle, formulated by Einstein generalizing Galileo 's and Newton's work, is a fundamental principle of modern physics. As such it should be tested as accurately as possible. Its most direct c onsequence, namely the University of Free Fall, can be tested in space , in a low Earth orbit, the crucial advantage being that the driving s ignal is about three orders of magnitude stronger than on Earth. GALIL EO GALILEI (GG) is a small space mission designed for such a high-accu racy test. At the time of print, GG has been selected by ASI (Agenzia Spaziale Italiana) as a candidate for the next small Italian mission. Ground tests of the proposed apparatus now indicate that an accuracy o f 1 part in 10(17) is within the reach of this small mission.