Spektr-R is a defunct 10-meter space radio telescope launched in 2011, which operated until equipment failure in 2019. Among its uses was providing one end of very-long-baseline interferometry (VLBI). Its elliptical orbit extends to 384,000 km. It operated at 1.35, 6.0, 18.0, and 92.0 cm radio wavelengths.
Spektr-R was one telescope of the RadioAstron program which coordinated its use as one end of a radio interferometer using various Earth-based radio telescopes as the other end. VLBI using it had the potential for extreme angular resolution (0.01 microarcseconds at the extreme end of its orbit), but required a bright radio source because of Spektr-R's 10-meter dish, small for a radio telescope.