See presentation by B. Christophe, “Gravity Advanced Package, a fundamental physics experiment for Jupiter Ganymede
Orbiter Mission”, at the recent Gravitation and Fundamental Physics in Space, the GPhyS “Kick-Off” Colloquium, Les
Houches, 20 – 22 October, 2009, at
http://gphys.obspm.fr/LesHouches2009/Program.html.