The Lyappa (or Ljappa) arm, officially Automatic system of re-docking (), was a robotic arm used during the assembly of the Soviet/Russian

space station A space station (or orbital station) is a spacecraft which remains orbital spaceflight, in orbit and human spaceflight, hosts humans for extended periods of time. It therefore is an artificial satellite featuring space habitat (facility), habitat ...

Mir ''Mir'' (, ; ) was a space station operated in low Earth orbit from 1986 to 2001, first by the Soviet Union and later by the Russia, Russian Federation. ''Mir'' was the first modular space station and was assembled in orbit from 1986 to ...

''. Each of the ''

Kvant-2 Kvant-2 (; English: Quantum-II/2) (77KSD, TsM-D, 11F77D) 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 w ...

'', ''

Kristall The Kristall () (77KST, TsM-T, 11F77T) module was the fourth module and the third major addition to ''Mir''. As with previous modules, its configuration was based on the 77K (TKS) module, and was originally named "Kvant 3". It was launched on Ma ...

'', ''

Spektr Spektr (; ) (TKM-O, 77KSO, 11F77O) was the fifth module of the Mir Space Station. The module was designed for remote observation of Earth's environment and contained atmospheric and surface research equipment. Spektr also had four solar arra ...

'' and ''

Priroda The Priroda (; ) (TsM-I, 77KSI, 11F77I) 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. The ...

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

Mir Core Module ''Mir'' ( lit. ''Peace'' or ''World''), 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 l ...

's forward (or axial) port, grappled 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 degrees for docking to one of the four radial docking ports. Likewise the Prichal module will host the grapple fixtures for the redocking of future modules docked to it from one port to another using the Lyappa Arm attached to those modules, if needed. Both the Wentian and Mengtian modules of the

Tiangong space station Tiangong (), officially the ''Tiangong'' space station (), is a permanently crewed space station constructed by China and operated by China Manned Space Agency. Tiangong is a modular design, with modules docked together while in low Earth o ...

carry arms to enable them to manoeuvre around the docking hub of the ''

Tianhe core module ''Tianhe'' (), officially the ''Tianhe'' core module (), is the first module to launch of the Tiangong space station. It was launched into orbit on 29 April 2021, as the first launch of the final phase of Tiangong program, part of the China ...

''. A mechanical arm dubbed the Indexing robotic arm, which looks similar to the Lyappa arm, allowed them to dock to a radial port of the CCM. It is different from Lyappa as it works on a different mechanism. Lyappa arm is needed to control the pitch of the spacecraft and redocking in a different plane. Where as the Indexing robot arm is needed for docking in the same plane. In addition to this arm used for docking relocation, the Chinarm on ''Tianhe'' module could also be used as a backup.

Naming

The word “Lyappa” does not exist in Russian. It is probably a corruption of .

Gallery

Image:Lyappa arm and attach fixture on Mir.jpg , Lyappa arm and attach fixture on Mir Image:Mir arm1.jpg, Lyappa arm at the RKK Energiya museum Image:RP1357 p165 Repositioning Kvant module using Lyappa arm.svg , A diagram showing how the arm was used to relocate ''

''. File:Mir Docking Cone Placement and Module Movements.pdf, A diagram showing the ''Konus'' drogue and module movements around ''Mirs docking node

Naming

Gallery

References

Further reading