The Intelsat 3 spacecraft were used to relay commercial global telecommunications including live TV. Three of the 8 satellites in the series (F1, F5, F8) were unusable due to launch vehicle failures, and most of the remainder did not achieve their desired lifetimes.
Geostationary OrbitISIS 1 (International Satellite for Ionosphere Studies) was an ionospheric observatory instrumented with sweep- and fixed-frequency ionosondes, a VLF receiver, energetic and soft particle detectors, an ion mass spectrometer, an electrostatic probe, an electrostatic analyzer, a beacon transmitter, and a cosmic noise experiment.
Elliptical OrbitUS-A (Upravlenniye Sputnik Aktivny) were active radar satellites for ocean surveillance. The high power consumtion of the active radar required a nuclear reactor as power source. The satellites were known as RORSAT in the west. The US-AO series consisted of satellites, which tested all the system components but the nuclear reactor. They were battery powered.
Low Earth Orbit