Zarya: The Control Module
Zarya (ZAR-yah) is a 21-ton power, communication and spacecraft control element that on Nov. 20, 1998, was rocketed into history as the first International Space Station component to be sent into orbit.
The 41-foot-long, 13.5-foot-wide Control Module (Russian acronym: FGB) at first is the fledgling Station's primary link with Earth, as well as its only source of power, propulsion and control. It is an SUV -- a Space Utility Vehicle -- that's all business.
NASA funded Zarya's construction in Moscow by Boeing and Khrunichev State Research and Production Space Center. Work on the pressurized module began in 1994 and was completed in 1998.
Zarya (in English: "Sunrise," to symbolize the dawn of a new era in space) automatically powered-up its systems and spread its wing-like solar arrays shortly after it achieved initial orbit, an elliptical path that varied in altitude from 137 to 211 miles.
The arrays and six nickel-cadmium batteries can generate an average of 3 kilowatts of electrical power, more than sufficient for the equipment used by Zarya and its mate Unity.
Zarya initially was confronted with a days-long battery of tests. When those were successfully completed, it was commanded to ignite its two large engines, climb to 240 miles and switch to a circular orbit, signaling completion of its operational tests.
The module's engines and 36 steering jets began orbiting the Earth with a six-ton reservoir of propellant to fuel altitude and orientation changes.
Zarya provided most of the First Element critical system functions until Russia's Service Module, the Station's early core and living quarters, arrived July 2000. Its side docking ports are for use by Russia's Soyuz piloted spacecraft and Progress remotely-piloted re-supply vehicles.
As assembly progresses, Zarya's roles will be assumed by other Station elements and it will be used primarily as a passageway, docking port and fuel storage site.