Zvezda (ISS)

Infobox Space station
station = ISS Zvezda
station_

station_image_caption = The "Zvezda" service module of the ISS with "Zarya" to the left and a docked Progress spacecraft to the right.
insignia = ISS insignia.svg
insignia_size = 120px
sign = International Space Station
launch = 2000-07-12
Docked with ISS on 26 July.
launch_pad = Baikonur Cosmodrome, Kazakhstan
mass = convert|19051|kg|lb
length = convert|13.1|m|ft
width = convert|29.7|m|ft
diameter = 4.15 m
pressure = 101.3 kPa (29.91 inHg)
perigee = convert|319.6|km|nmi
apogee = convert|346.9|km|nmi
inclination = 51.63 degrees
altitude = convert|333.3|km|nmi
speed = convert|27743.8|km/h|mph|lk=on
period = 91.20 minutes
orbits_day = 15.79
in_orbit = 2534 days
occupied = 2316 days
orbits = 40,010
as_of = June 20, 2007
stats_ref = [cite web |url=http://spaceflight.nasa.gov/station/isstodate.html |title=The ISS to Date |work=NASA.gov |date=2007-02-22 |accessdate=2007-06-24] [cite web |url=http://spaceflight.nasa.gov/spacenews/reports/issreports/2006/iss06-7.html |title=International Space Station Status Report #06-7 |work=NASA.gov |date=2006-02-17 |accessdate=2007-06-24] [cite web |url=http://www.nasa.gov/mission_pages/station/structure/elements/sm.html |title=NASA - Zvezda Service Module |work=NASA.gov |date=2006-10-14 |accessdate=2007-07-10]
configuration_

---

configuration_caption = On-orbit configuration of the "Zvezda" service module

"Zvezda" ( _ru. Звезда, meaning "star"), DOS-8, also known as the "Zvezda Service Module", is a component of the International Space Station (ISS). It was the third module launched to the station, and provides some of the station's life support systems, as well as living quarters for two crew members. It is the structural and functional center of the Russian portion of the station - the Russian Orbital Segment.

The module was manufactured by S.P. Korolev Rocket and Space Corporation Energia and is currently the only fully Russian-built and funded module besides "Pirs". ("Zarya" was built by Russia, but was funded and is owned by the United States). "Zvezda" was launched on a Proton rocket on July 12, 2000 and docked with the "Zarya" module on July 26. The rocket used for the launch was one of the first to carry advertising; it was emblazoned with the logo of the fast food chain Pizza Hut,Space.com, 30 September 1999. [http://www.space.com/businesstechnology/business/pizza_hut_990930_wg.html Pizza Hut Puts Pie in the Sky with Rocket Logo] . Accessed 27 June 2006.] for which the company paid US$1 million.Fact|date=May 2008

Origins

The basic structural frame of "Zvezda", known as "DOS-8", was initially built in the mid-1980s to be the core of the "Mir-2" space station. This means that "Zvezda" is similar in layout to the core module (DOS-7) of the "Mir" space station. It was in fact labeled as "Mir"-2" for quite some time in the factory. Its design lineage thus extends back to the original Salyut stations. The space frame was completed in February 1985 and major internal equipment was installed by October 1986.

Design

Zvezda consists of a cylindrical "Work Compartment" where the crews work and live, a cylindrical "Transfer Chamber" which has one docking port, an unpressurized "Assembly Compartment" surrounding the Transfer Chamber, and a spherical "Transfer Compartment" with three docking ports. The component weights 18,051 kg (42,000 lb) and had a length of 13.1 meters (43 feet). The solar panels extend 29.7 meters (97.5 feet).

The "Transfer Compartment" attaches to the "Zarya" module, and has docking ports intended for the Science Power Platform and the Universal Docking Module. Currently the lower port contains the Russian Docking Compartment and the other is empty. It could be used as an airlock; however, if the hatch failed, it would be impossible to travel to the rest of the station, so this capability has never been used. Once the Multipurpose Laboratory Module comes, before the launch, two crewmembers of Expedition 18 will remove the Docking Compartment, relocate it on the zenith port of Zvezda, and install and activate the Multipurpose Laboratory and the European Robotic Arm.

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 cosmonauts, a NASA-provided treadmill and a bicycle for exercise, toilet and other hygiene facilities and 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 window in the Working Compartment, one in each crew compartment, and several more. It also contains the Elektron system that electrolyzes condensed humidity and waste water to provide hydrogen and oxygen. The hydrogen is expelled 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 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 crew 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, a system which removes carbon dioxide from the air based on the use of regenerable adsorbers of carbon dioxide gas. "Zvezda" has been criticized for being excessively noisy and the crew has been observed wearing earplugs inside it.

Connection to the ISS

On July 26, 2000, "Zvezda" became the third component of the ISS when it docked at the aft port of "Zarya". ("Zarya" had already been attached to the U.S. "Unity" module.) Later in July, the computers aboard "Zarya" handed over ISS commanding functions to computers on "Zvezda". [cite web |url=http://science.ksc.nasa.gov/shuttle/missions/sts-106/mission-sts-106.html |title=STS-106 |publisher=NASA]

On September 11, 2000, two members of the STS-106 Space Shuttle crew completed final connections between "Zvezda" and "Zarya": during a 6 hour, 14 minute extravehicular activity (EVA), astronaut Ed Lu and cosmonaut Yuri Malenchenko connected nine cables between "Zvezda" and "Zarya", including four power cables, four video and data cables and a fiber-optic telemetry cable. [cite web |url=http://science.ksc.nasa.gov/shuttle/missions/sts-106/news/sts-106-mcc-07.txt |title=STS-106 Report # 07 |publisher=NASA] The next day, STS-106 crew members floated into "Zvezda" for the first time, at 12:20 a.m. CDT on September 12, 2000. [cite web |url=http://science.ksc.nasa.gov/shuttle/missions/sts-106/news/sts-106-mcc-09.txt |title=STS-106 Report # 10 |publisher=NASA]

"Zvezda" provided early living quarters, a life support system, a communication system ("Zvezda" introduced a 10Mbit/s Ethernet network to the ISS [ [http://gltrs.grc.nasa.gov/reports/2002/TM-2002-211310.pdf ISS and STS Commercial Off-The-Shelf Router Testing] , Ivancic, Bell and Shell, NASA Technical Memo TM-2002-211310] ), electrical power distribution, a data processing system, a flight control system, and a propulsion system. These quarters and systems have since been supplemented by additional ISS components.

The two main engines on "Zvezda" can be used to raise the station's altitude. This was done on 25 April 2007. This was the first time the engines had been fired since "Zvezda" arrived in 2000. [cite web |url=http://www.nasa.gov/home/hqnews/2007/apr/HQ_SS0723_station_status.html |title=International Space Station Status Report: SS07-23 |publisher=NASA]

Launch risks

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.

Gallery

References