Mir
The Soviet Union launches the first module of its new Mir space station, a new modular station design building on the Soviets’ years of experience with the Salyut stations. One end of this “core” module is a six-sided structure, with docking ports on five sides; this design will allow new modules to be added onto Mir in all directions, and will potentially allow for several Soyuz or unmanned Progress cargo vehicles to be docked simultaneously, a design element which will later be carried forward to the International Space Station.