Stella is a 48 kilogram (106 pound) French satellite that was launched along with the French Earth Observation Satellite Spot 3. Stella was placed on a Ariane 40 rocket. Stella was released at an altitude near 497 miles/800 km in a quasi-circular orbit at an inclination of 98 degrees.
The Stella satellite is a dense sphere of uranium alloy with 60 laser reflectors on the surface. Reflected laser beams enabled accurate geodetic measurements for the determination, with an accuracy of 1 cm, of the geoid, of oceanic and terrestrial tides, and of tectonic movements. Stella isn’t alone out there. She is joined by her still operational twin, Starlette, that was launched in 1975.