In collaboration with the European Space Agency, a 25 m diameter space radio telescope was studied for launch by Energia in 2001. The satellite would have permitted study of the mechanisms of the generation of relativistic energy, mapped in detail radio sources and quasars, studied the black matter problem, and detected new types of celestial objects. The 27.8 metric ton satellite would be equipped with a 5 kWt power supply, of which 1.5 kW would be available for scientific instruments. Its radio interferometer would operate in the frequency range of 5 to 200 GHz. During its five year life in a 63.45 deg orbit, it would maneuver to successively higher orbits. Two years would be spent in a 5,000 km x 20,000 km orbit, followed by two years in a 5,000 x 40,000 km orbit, and the final year in a 5,000 x 150,000 km orbit.

Typical orbit: 5,000 km x 20-40,000 km orbit. Mass: 27,800 kg (61,200 lb).