Although this Soviet lunar mission didn't achieve its planned orbit, it still served as a successful communications test.
This spacecraft was a one-off high apogee Earth satellite developed to acquire data on new telecommunications systems for upcoming crewed missions to the Moon.
Besides a usual complement of telemetry and communications equipment, the vehicle also carried a transceiver as part of the long-range communications system (Dal’nyy radiokompleks, DRK) and the BR-9-7 telemetry system, equipment designed to work with the new SaturnMS-DRK ground station located near the village of Saburovo, about 6 miles (10 kilometers) from NIP-14, a station close to Moscow belonging to the Soviet ground-based tracking network.
The spacecraft was similar to Luna 11 but had a slightly lengthened ((by about 6 inches or 15 centimeters) instrument container so as to accommodate the modified DRK and new BR-9-7 telemetry systems.
Mission designers had planned to send the probe into a highly elliptical orbit with an apogee of 155,343 miles (250,000 kilometers), but the Blok L upper stage cut off too early. Instead, the spacecraft, named Kosmos 159, entered a lower orbit of 236 x 37,655 miles (380 × 60,600 kilometers) at 51.5-degree inclination.
Despite the incorrect orbit, controllers were able to accomplish the original mission, carried out over a period of nine days during which it was discovered that the energy potential of the UHF downlink from the spacecraft to the ground was 1 to 2 orders magnitude below the calculated value.
Kosmos 159 reentered Earth’s atmosphere on November 11, 1967.
Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.