ISS Russian Segment

Zarya Functional Cargo Block

Zarya Module

FGB Zarya

FGB Zarya is a US module technically integrated into ISS RS.


  • docking, on the side of the pressurized adapter, of the US segment elements, and, on the side of the conical back end and nadir docking unit, of the Russian segment elements;
  • repeated reception of propellant from Progress-type resupply spacecraft, its storage and transfer to the tanks of the Service Module Zvezda for performing dynamic operations - orbital reboost, ISS attitude control and stabilization;
  • supplying the space station with electric power at the initial phase of operation and supporting short stays of the crews;
  • final ascent of FGB from a 200 km parking orbit to a 350400 km assembly orbit;
  • attitude control, stabilization and reboost of the FGB + Node1 stack prior to its docking with the Service Module;
  • docking the FGB + Node1 stack with the Service Module.

Key specifications

Parameter Value

Mass in orbit, kg

20 260

Body length, mm

12 990

Maximum diameter, mm

4 100

Volume of pressurized compartments, m3


Solar array wing span, mm

24 400

The area of photovoltaic elements, m2


Guaranteed daily averaged 28V electric power supply, kW


US segment electric power supply, kW

up to 2

Propellant load mass, kg

up to 6 100

Note: at present solar arrays on FGB Zarya are stowed. Electrical power is supplied from the US Orbital Segment of the ISS.

FGB Zarya uses the configuration that was proven in the development and operation of the Mir space station modules. FGB systems were subdivided into service systems and station systems. Service systems provide the module operation in free flight and during its rendezvous and docking with the Service Module, while control of the module as a part of the space station is provided by the station systems.

FGB consists of the Instrumentation and Cargo Compartment (ICC) and the Pressurized Adapter (PA) designed to accommodate onboard systems supporting mechanical docking with other ISS modules and spacecraft arriving at ISS. PA is separated from the ICC by a spherical bulkhead which has an 800 mm manhole. On the outer surface of the PA, there is a special feature for mechanical grappling of the FGB by the Shuttle Orbiter robotic arm. The pressurized volume of the ICC is 64.5 m3, of the PA - 7.0 m3. The internal volume of the ICC and PA is divided into two areas: instrumentation area and living area. The instrumentation area accommodates onboard systems units. The living area is designed for crew work. It contains elements of the systems for monitoring and controlling onboard equipment, as well as for emergency caution and warning. The instrumentation area is separated from the living area by interior panels.

On November 20, 1998, at 8 h 40 min, Moscow Time, launch vehicle Proton successfully put FGB Zarya into Earth orbit.

On July 26, 2000, the functional cargo module docked with Service Module Zvezda.

ISS Crew

Hoshide  AkihikoHoshide

leg Novitskiy Novitskiy

Petr Dubrov Dubrov

Mark Vande Hei Vande Hei

Robert Shane

Megan McArthur McArthur