  We focus on the possibility of measuring the gravitomagnetic effects due to
the rotation of the Earth, by means of a space-based experiment that exploits
satellites in geostationary orbits. Due to the rotation of the Earth, there is
an asymmetry in the propagation of electromagnetic signals in opposite
directions along a closed path around the Earth. We work out the delays between
the two counter-propagating beams for a simple configuration, and suggest that
accurate time measurements could allow, in principle, to detect the
gravitomagnetic effect of the Earth
