An optical lever to read out the pendulum motion, allows the detection of linear and quadratic gravitational coupling. Furthermore we want to show 1/r dependence of the force and confirm the coupling constant G in a new low mass regime. Moving the Experiment from Vienna to the outstandingly quiet conditions in the Conrad Observatory is decisive factor in achieving this goal. There is no more urban seismic noise which makes continuous long term measurements possible, magnetite noise is very low and the temperature is remarkably stable . This will open up the possibility to explore the gravitational coupling for even smaller masses, probe dark energy theories and test short range forces in a new mass regime.