It was on this date in 1986 that Russia launched the first module of its long-lived Mir space station. Originally planned a decade earlier as an improved Salyut (1-piece) station, it would take the better part of a decade for Mir to hit the production phase due to plan changes (into a multi-module station) and financial troubles, with the goal of a first module launch by the 27th Communist Party Congress, set to open February 25, 1986.
The launch met the goal by 6 days.
In the intervening decade, Mir would come to include 7 modules, the last of which was attached in 1996. At the same time, with the collapse of the Soviet Union and end of the Cold War in 1991, Mir became an unofficial international space station, hosting astronauts from other countries, including the United States. By 1997, the 11-year old station (designed to fly for only 5years) had really started to show its age as it was plagued by constant mechanical problems to the point where visitors were openly questioning the station's safety.
The beginning of the end for Mir would come on June 25, 1997 when an unmanned supply ship crashed into the space station after a failed docking attempt. The result: a smashed solar panel resulting in a power loss and a punctured module. Additionally, the station was spent into an uncontrolled spin, which was only stopped after the crew estimated the rate of spin by visual estimate (the computers were knocked out) and radioing the guess to mission control, which was able to fire the station's rockets and stabilize the station because the guess, based on the apparent motion of the stars, was right.
After the accident, Mir would continue to fly as a manned station for another 3 years. During that time, the Russians expressed optimism that Mir could be retrofitted and used for future research or, in a preview of things to come, as a commercial venture wherein rich space tourists would pay to be flown to the station aboard Soyuz rockets. However, previous commitments to the then in-planning International Space Station left Russia with no money to fix Mir, which the nation reluctantly abandoned in 2000 before it was eventually de-orbited in 2001.