# #Mon Aug 09 12:06:31 CEST 2010 Text__wPOkcKOdEd-WfYQ0GneCwQ_title=Test Masses of STEP Text__wPOkcKOdEd-WfYQ0GneCwQ_text=STEP explores the free fall of two different test masses in the gravitational field of the Earth. The test masses - shaped in a specific way - are released into an orbit on a polar route. The satellite and its equipment are carefully designed, in order to reduce as much as possible all influences which could bias the free falling test masses, such as the air friction of Earths atmosphere and the magnetic field and the particle fluxes from the sun.