Functional Cargo Block

The ISS space station module Zarya, until the launch of Nauka the latest space station module to be based on the Functional Cargo Block (FGB) design.

The Functional Cargo Block or FGB (from the Russian "Функционально-грузовой блок", [Funktsionalno-gruzovoy blok] Error: {{Lang}}: text has italic markup (help) or ФГБ, GRAU index 11F77) was part of the TKS spacecraft of the Soviet Salyut space station program.

Several space station modules have been derived from this spacecraft and are to some extent called Functional Cargo Block (FGB) as well, like the Zarya FGB module.

The FGB provides "functional" support in the form of electrical power, propulsion, guidance and docking; The support for "cargo" operations is supplied in the form of a pressurized habitable cargo storage section (accessible by the crew) and the externally mounted fuel tanks.

History

Main articles: Almaz, TKS (spacecraft), and VA spacecraft

The Functional Cargo Block (FGB) was originally developed as support for the VA spacecraft – with both together forming the TKS spacecraft, intended for resupply flights to the Almaz space stations. For Salyut space station modules, it was initially intended that the first such modules be derived from the Progress spacecraft (which in turn is a Soyuz spacecraft derivate), and not the FGB. As the Almaz program wound down, TKS test missions to Salyut stations were used to gather experience on docking larger modules to space stations. The TKS flights proved that the FGBs could form the basis of such a space station module, with the TKS being large and flight ready, and having a considerable larger capacity than the Progress – so the FGB and not the Progress became the basis of Soviet and Russian space station modules. The Gamma observatory, the initially intended first Progress-based research module, would became after these and other changes the free-flying Gamma satellite.

Design

The basic layout of the exemplary Zarya FGB consists of two sections:

• The Instrumentation and Cargo Compartment (ICC) with a pressurized volume of 64.5 cubic metres (2,280 cu ft)
• The Pressurized Adapter (PA) with a pressurized volume of 7.0 cubic metres (250 cu ft)

The PA is separated from the ICC by a spherical bulkhead which has an 800 mm manhole. Both pressurized sections contains working and living areas, in addition to instrumentation separated by interior panels.

Functional Cargo Blocks

FGB based spacecraft include in addition to the original TKS spacecraft:

• Polyus spacecraft
• Kvant-1 (Mir module)
• Kvant-2 (Mir module)
• Kristall (Mir module)
• Spektr (Mir module)
• Priroda (Mir module)
• Zarya (ISS module)
• Nauka (ISS module)