The LAGEOS system

The LAGEOS system is defined and its rationale is developed. Key features of the baseline system specified included a circular orbit at 5900 km altitude and an inclination of 110 deg, and a satellite 60 cm in diameter weighing some 385 kg and mounting 440 retroreflectors, each having a diameter of 3.8 cm, leaving 30% of the spherical surface available for reflecting sunlight diffusely to facilitate tracking by Baker-Nunn cameras. The satellite weight was increased to 411 kg in the actual design through the addition of a 4th-stage apogee-kick motor. The number and diameter of the retroreflectors are now 426 and 3.81 cm, respectively. The net effect of these partially compensating changes is not significant. The diffusely reflecting area was increased to 47% of the satellite surface.