The Lyappa arm was a robotic arm used during the assembly of the Soviet/Russian space station

Space station

A space station is a spacecraft capable of supporting a crew which is designed to remain in space for an extended period of time, and to which other spacecraft can dock. A space station is distinguished from other spacecraft used for human spaceflight by its lack of major propulsion or landing...

 Mir

Mir

Mir was a space station operated in low Earth orbit from 1986 to 2001, at first by the Soviet Union and then by Russia. Assembled in orbit from 1986 to 1996, Mir was the first modular space station and had a greater mass than that of any previous spacecraft, holding the record for the...

. Each of the Kvant-2

Kvant-2

Kvant-2 was the third module and second major addition to the Mir space station. Its primary purpose was to deliver new science experiments, better life support systems, and an airlock to Mir. It was launched on November 26, 1989 on a Proton rocket. It docked to Mir on December 6...

, Kristall

Kristall

The Kristall module was the fourth module and the third major addition to the Mir space station. As with previous modules, its configuration was based on the 77K module, and was originally named "Kvant 3". It was launched on May 31, 1990 on a Proton rocket...

, Spektr

Spektr

Spektr was the fifth module of the Mir Space Station. The module was designed for remote observation of Earth's environment containing atmospheric and surface research equipment...

and Priroda

Priroda

The Priroda module was the seventh and final module of the Mir Space Station. Its primary purpose was to conduct Earth resource experiments through remote sensing and to develop and verify remote sensing methods...

modules was equipped with one of these arms, which, after the module had docked to the core module

Mir Core Module

Mir , DOS-7, was the first module of the Soviet/Russian Mir space station complex, in low Earth orbit from 1986 to 2001. Generally referred to as either the core module or base block, the module was launched on 20 February 1986 on a Proton-K rocket from LC-200/39 at the Baikonur Cosmodrome...

's forward port, grapples one of two fixtures positioned on the core module's hub module. The module's main docking probe was then retracted, and the arm raised the module so that it could be pivoted 90° for docking to one of the four radial docking ports.