Fobos 2

Goals: Fobos 1 and 2 were part of an ambitious Russian plan to explore Mars and its moon Phobos. Each spacecraft comprised an orbiter for long term studies of the planet and a lander to study geological and climatic conditions on Phobos. Fobos 2 had an additional payload on board, a 110-kg "hopper" designed to make up to ten 20-m jumps across the Phobos surface to gather surface data on the tiny Martian moon. Fobos 2 also had a slightly different instrument complement.

Accomplishments: Fobos 2 did take high-resolution photos of Mars' moon Phobos on 23 February (at a range of 860 km), 28 February (320 km) and 25 March 1989 (191 km). However before the release of its lander, scheduled for 4-5 April 1989, during a regularly planned communications session on 27 March at 15:58 UT, there was no word from the spacecraft. A weak signal was received between 17:51 and 18:03 UT, but there was no telemetry information. The mission was declared lost on 15 April 1989.

Source

Siddiqi, Asif A. Beyond Earth: A Chronicle of Deep Space Exploration, 1958-2016. NASA History Program Office, 2018.