  The possibility of analyzing the node Omega of the GP-B satellite in order to
measure also the Lense-Thirring effect on its orbit is examined. This feature
is induced by the general relativistic gravitomagnetic component of the Earth
gravitational field. The GP-B mission has been launched in April 2004 and is
aimed mainly to the measurement of the gravitomagnetic precession of four
gyroscopes carried onboard at a claimed accuracy of 1% or better. The aliasing
effect of the solid Earth and ocean components of the solar K_1 tidal
perturbations would make the measurement of the Lense-Thirring effect on the
orbit unfeasible. Indeed, the science period of the GP-B mission amounts to
almost one year. During this time span the Lense-Thirring shift on the GP-B
node would be 164 milliarcseconds (mas), while the tidal perturbations on its
node would have a period of the order of 10^3 years and amplitudes of the order
of 10^5 mas.
