ISS Zvezda
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Zvezda_Service_Module_under_construction.jpg
ISS Zvezda is a Russian service module for the International Space Station. Its name is from the Russian Звезда, meaning 'star'. The module, similar in layout to the core module of the Mir space station, was manufactured by Korolev, launched by a Proton rocket on July 12, 2000, and docked with the ISS on July 26. The basic structural frame was initially built in the mid 1980's and designed to be the core of the Mir 2 space station, which the ISS replaced, and, in fact, was labeled as "Mir-2" for quite some time in the factory. The design lineage of Zvezda extends back to the original Salyut stations.
Due to Russian financial problems, Zvezda was launched with no backup and no insurance. Due to this risk, NASA had constructed an Interim Control Module in case it was delayed significantly or destroyed on launch. However, without the Service Module, it would be several more flights before the ISS would be able to support a permanent crew.
Zvezda is the structural and functional center of the Russian portion of the ISS -- the Russian Orbital Segment and the early core of the station. Zvezda provided early living quarters, a life support system, a communication system, electrical power distribution, a data processing system, a flight control system, and a propulsion system. These quarters and systems are to be supplemented or replaced by future ISS components.
Zvezda consists of a cylindrical "Work Compartment" where the crews work and live, a cylindrical "Transfer Chamber" which has one docking port, an unpressurised "Assembly Compartment" surrounding the Transfer Chamber, and a spherical "Transfer Compartment" with three docking ports.
The Transfer Compartment attaches currently to the Zarya module and has docking ports intended for the Science Power Platform and the Universal Docking Module. However, currently the lower port contains the Russian Docking Compartment and the other is empty. It can be used as an airlock, however, if the hatch fails, it will be impossible to travel to the rest of the station, so that capability has never been used.
The Assembly compartment holds external equipment such as thrusters, antennas, and propellant tanks.
The Transfer Chamber is equipped with automatic docking equipment and is used to service Soyuz and Progress spacecraft.
Zvezda contains sleeping quarters for two astronauts, A NASA-provided treadmill and a bicycle for exercise, toilet and other hygiene facilities, a galley with a refrigerator and freezer. It contains the primary Russian computers for guidance and navigation. It has a total of 14 windows -- three 9-inch diameter windows in the forward Transfer Compartment, a 16-inch in the Working Compartment, a window in each crew compartment, and several more. It also contains the Elektron system that uses condensed humidity and waste water, electrolyzes it, and provides hydrogen and oxygen. The hydrogen is exhausted into space and the oxygen is used for breathing air. The condensed water and the waste water can be used for drinking in an emergency, but ordinarily other fresh water from Earth is used. There are 16 small thrusters and two large thrusters for propulsion and eight batteries for storing power.
The Elektron system has required significant maintenance work, having failed several times and requiring the astronauts to use Solid Fuel Oxygen Generator canisters (commonly called "Oxygen Candles"), which were the cause of a fire on Mir, when it has been broken for extended amounts of time. It also contains the Vozdukh system to remove Carbon Dioxide from the atmosphere. It was criticized for being excessively noisy inside of the Zvezda and, in fact, Astronauts have been observed wearing earplugs inside of it.
There has been, at times, a 50 Ruble note, a dollar, and a Euro attached to the wall. When asked to explain it, the astronauts suggested that it was there to ask each other for favors.
Specifications
- Length: 13.1 m
- Maximum Diameter: 4.15 m.
- Total Mass: 19,050 kg.
- Solar array span: 29.72 m
- Electrical System: Solar cells.de:Swesda