Venera 15 was a spacecraft sent to Venus by the Soviet Union. This uncrewed orbiter was to map the surface of Venus using high resolution imaging systems. The spacecraft was identical to Venera 16 and based on modifications to the earlier Venera space probes. Venera 15 was launched on June 2, 1983, at 02:38:39 UTC and reached Venus's orbit on October 10, 1983. The spacecraft was inserted into Venus orbit a day apart from Venera 16, with its orbital plane shifted by an angle of approximately 4° relative to the other probe. This made it possible to reimage an area if necessary. The spacecraft was in a nearly polar orbit with a periapsis ~1000 km, at 62°N latitude, and apoapsis ~65000 km, with an inclination ~90°, the orbital period being ~24 hours.

Wikipedia: https://en.wikipedia.org/wiki/Venera_15. Related NASA reference: https://nssdc.gsfc.nasa.gov/planetary/chronology.html#1983. Description adapted from Wikipedia contributors (CC BY-SA 4.0; https://creativecommons.org/licenses/by-sa/4.0/).