The Zarya Control Module, also known by the technical term Functional Cargo Block and
the Russian acronym FGB, was the first component launched for the International Space Station. This module was designed to
provide the station's initial propulsion and power. The 19,323 kilogram pressurized module
was launched on a Russian Proton rocket in November 1998.
The U.S.-funded and Russian-built Zarya, which means "Sunrise" when
translated into English, is a U.S. component of the station, although it was built and
launched by Russia. The module was built by the Khrunichev State Research and Production
Space Center, which is also known as KhSC, in Moscow under a subcontract to The Boeing
Company for NASA. Only weeks after Zarya reached orbit, Space Shuttle Endeavour
made a rendezvous and attached a U.S.-built connecting module called Node
1, or Unity. The Zarya Module provided orientation control, communications and
electrical power attached to the passive Node 1 while the station awaited launch of the
third component, a Russian-provided crew living quarters and early station core known as
the Zvezda Service Service Module. The Service Module enhanced or
replaced many functions of Zarya. The Zarya module is now used primarily for its storage
capacity and external fuel tanks.
The Zarya Module is 12.6 meters long and 4.1 meters at its widest point. It has an
operational lifetime of at least 15 years. Its solar arrays and six nickel-cadmium
batteries can provide an average of 3 kilowatts of electrical power. Its side docking
ports accommodate Russian Soyuz piloted spacecraft and
unpiloted Progress resupply spacecraft. Each of the two solar
arrays is 10.7 meters long and 3.4 meters wide. The module's 16 fuel tanks combined can
hold more than 5.4 tons of propellant. The attitude control system for the module includes
24 large steering jets and 12 small steering jets. Two large engines are available for
reboosting the spacecraft and making major orbital changes.
Construction of the Zarya Module began at KhSC in December 1994. It was shipped to the
Baikonur Cosmodrome, Kazakhstan, launch site to begin launch preparations in January 1998.
The three-stage Proton rocket launched the module into a 220.4- by 339.6-kilometer orbit.
During launch, the module's systems were in an idle mode to conserve battery power. After
reaching the initial elliptical orbit and separating from the Proton's third stage, a set
of preprogrammed commands automatically activated the module's systems and deployed the
solar arrays and communications antennas. Using the Russian Kurs system, the Zarya
performed an automated and remotely piloted rendezvous and docking with the Service Module
in orbit. After several days of operational tests, the module was commanded to fire its
engines and circularize its orbit at an altitude of about 386.2 kilometers, the orbit at
which Endeavour made rendezvous and captured the spacecraft to
attach it to the U.S.-built Unity Connecting Module.
FGB 2 was built as a back-up in case of a launch failure. It was considered to be
converted into the UDM (Universal Docking Module) or the DSM (Docking and Stowage Module). Now it is planned to become the MLM (Multipurpose Laboratory Module).