A space test of general relativity

In this paper we describe a test in space of general relativity and gravitational physics: the measurement of this effect, obtained in 1995-98, using two laser-ranged satellites. We first briefly present the gravitomagnetic field and the Lense-Thirring effect in general relativity. We then review the method proposed to measure this effect by analyzing the orbits of the two laser-ranged satellites LAGEOS and LAGEOS II, and we report on the corresponding measurement of the Lense-Thirring effect by analyzing the data of LAGEOS and LAGEOS II with the orbital programs GEODYN-SOLVE, using the Earth gravitational models JGM-3 and EGM-96 and our method. The first result was obtained in 1995, and the most accurate measurements were obtained in 1998 using EGM-96, with an estimated uncertainty of about 20%-30%.