iternational space station (page 3)
Pressurised modules
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Unity node (top) and Zarya (with solar panels deployed) in 1998
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From top to bottom: Unity, Zarya, Zvezda modules with Progress M1-3 docked |
Zarya (Russian: Заря́; lit. dawn), also known as the Functional Cargo Block or FGB (Russian: ФГБ), was the first module of the station, launched on 20 November 1998 by a Russian Proton-K rocket flying from Site 81/23 at the Baikonur in Kazakhstan. Zarya was placed into an initial parking orbit at an altitude of 400 km (250 mi). Zarya provided attitude control, communications and electrical power for the station prior to the arrival of the Zvezda module. The FGB was derived from the TKS spacecraft developed during the Salyut programme.
Zarya can store 6,100 kg of propellant, which can be transferred to and from ships docked to the Russian Orbital Segment, or the Russian part of the space station. Zarya was originally intended as a module for the Russian Mir space station, but was not flown.[citation needed] Development costs for Zarya were paid for by Russia (and the former Soviet Union), spread across previous space station programmes,[citation needed] and some construction and preparation costs were paid for by the United States.
Unity, or Node 1, is one of three nodes, or passive connecting modules, in the US Orbital Segment of the station. It was the first US-built component of the Station to be launched. Cylindrical in shape, with six berthing locations facilitating connections to other modules, Unity was carried into orbit by Space Shuttle Endeavour as the primary cargo of STS-88 in 1998.
Zvezda (Russian: Звезда, meaning "star"), also known as DOS-8 or the Service Module or SM (Russian: СМ). It provides all of the station's critical systems,[clarification needed] its addition rendered the station permanently habitable for the first time, adding life support for up to six crew and living quarters for two. Zvezda's DMS-R computer handles guidance, navigation and control for the entire space station.[104] A second computer which performs the same functions will be installed in the Nauka module, FGB-2.
The hull of Zvezda was completed in February 1985, with major internal equipment installed by October 1986. The module was launched by a Proton-K rocket from Site 81/23 at Baikonur, on 12 July 2000. Zvezda is at the rear of the station according to its normal direction of travel and orientation, its engines are used to boost the station's orbit. Alternatively Russian and European spacecraft can dock to Zvezda's aft port and use their engines to boost the station.
Destiny is the primary research facility for United States payloads aboard the ISS. In 2011, NASA solicited proposals for a not-for-profit group to manage all American science on the station which does not relate to manned exploration. The module houses 24 International Standard Payload Racks, some of which are used for environmental systems and crew daily living equipment. Destiny also serves as the mounting point for the station's Truss Structure.[105]
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Thomas Reiter (left), is attired in a liquid cooling and ventilation garment that complements the EMU style space suit worn by Jeffrey N. Williams in the Quest Airlock
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Quest is the only USOS airlock, Quest hosts spacewalks with both United States EMU and Russian Orlan spacesuits. Quest consists of two segments; the equipment lock, that stores spacesuits and equipment, and the crew lock, from which astronauts can exit into space. This module has a separately controlled atmosphere. Crew sleep in this module, breathing a low nitrogen mixture the night before scheduled EVAs, to avoid decompression sickness (known as "the bends") in the low pressure suits.[106]
Pirs (Russian: Пирс, meaning "pier"), (Russian: Стыковочный отсек), "docking module", SO-1 or DC-1 (docking compartment), and Poisk (Russian: По́иск; lit. Search), also known as the Mini-Research Module 2 (MRM 2), Малый исследовательский модуль 2, or МИМ 2. Pirs and Poisk are Russian airlock modules. Each of these modules have 2 identical hatches. An outward opening hatch on the MIR space station failed after it swung open too fast after unlatching, due to a small amount of air pressure remaining in the airlock.[107] A different entry was used, and the hatch repaired. All EVA hatches on the ISS open inwards and are pressure sealing. Pirs is used to store, service, and refurbish Russian Orlan suits and provides contingency entry for crew using the slightly bulkier American suits. The outermost docking ports on both airlocks allow docking of Soyuz and Progress spacecraft, and the automatic transfer of propellants to and from storage on the ROS.[108]
Harmony, is the second of the station's node modules and the utility hub of the USOS. The module contains four racks that provide electrical power, bus electronic data, and acts as a central connecting point for several other components via its six Common Berthing Mechanisms (CBMs). The European Columbus and Japanese Kibō laboratories are permanently berthed to two of the radial ports, the other two can used for the HTV. American Shuttle Orbiters docked with the ISS via PMA-2, attached to the forward port. Tranquility is the third and last of the station's US nodes, it contains an additional life support system to recycle waste water for crew use and supplements oxygen generation. Three of the four berthing locations are not used. One location has the cupola installed, and one has the docking port adapter installed.
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Not large enough for crew using spacesuits, the airlock on Kibō has a sliding drawer for external experiments.
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Columbus, the primary research facility for European payloads aboard the ISS, provides a generic laboratory as well as facilities specifically designed for biology, biomedical research and fluid physics. Several mounting locations are affixed to the exterior of the module, which provide power and data to external experiments such as the European Technology Exposure Facility (EuTEF), Solar Monitoring Observatory, Materials International Space Station Experiment, and Atomic Clock Ensemble in Space. A number of expansions are planned for the module to study quantum physics and cosmology.[109][110] ESA’s development of technologies on all the main areas of life support has been ongoing for more than 20 years and are/have been used in modules such as Columbus and the ATV. The German Aerospace Center DLR manages ground control operations for Columbus and the ATV is controlled from the French CNES Toulouse Space Center.
Kibō (Japanese: きぼう, "hope") is the largest single ISS module. This laboratory is used to carry out research in space medicine, biology, Earth observations, materials production, biotechnology, communications research, and has facilities for growing plants and fish. During August 2011, an observatory mounted on Kibō, which utilises the ISS's orbital motion to image the whole sky in the X-ray spectrum, detected for the first time the moment a star was swallowed by a black hole.[111][112] The laboratory contains a total of 23 racks, including 10 experiment racks and has a dedicated airlock for experiments. In a 'shirt sleeves' environment, crew attach an experiment to the sliding drawer within the airlock, close the inner, and then open the outer hatch. By extending the drawer and removing the experiment using the dedicated robotic arm, payloads are placed on the external platform. The process can be reversed and repeated quickly, allowing access to maintain external experiments without the delays caused by EVA's. Only the Russian and Japanese laboratories have this feature. A smaller pressurised module is attached to the top of Kibō, serving as a cargo bay. The dedicated Interorbital communications system allows large amounts of data to be beamed from Kibō's ICS, first to the Japanese KODAMA satellite in geostationary orbit, then to Japanese ground stations. When a direct communication link is used, contact time between the ISS and a ground station is limited to approximately 10 minutes per visible pass. When KODAMA relays data between a LEO spacecraft and a ground station, real-time communications are possible in 60% of the flight path of the spacecraft. Ground staff use telepresence robotics to conduct on-orbit research without crew intervention.
Cupola is a seven window observatory, used to view Earth and docking spacecraft. Its name derives from the Italian word cupola, which means "dome". The Cupola project was started by NASA and Boeing, but cancelled due to budget cuts. A barter agreement between NASA and the ESA resulted in the Cupola's development being resumed in 1998 by the ESA. The module comes equipped with robotic workstations for operating the station's main robotic arm and shutters to protect its windows from damage caused by micrometeorites. It features 7 windows, with a 80-centimetre (31 in) round window, the largest window on the station. The distinctive design has been compared to the 'turret' of the fictitious Millennium Falcon from the motion picture Star Wars;[113][114] the original prop lightsaber used by actor Mark Hamill as Luke Skywalker in the 1977 film was flown to the station in 2007,[115] and the Falcon rockets commercial ships that come to the station use, are named after the Millennium Falcon itself.
Rassvet (Russian: Рассве́т; lit. "dawn"), also known as the Mini-Research Module 1 (MRM-1) (Russian: Малый исследовательский модуль, МИМ 1) and formerly known as the Docking Cargo Module (DCM), is similar in design to the Mir Docking Module launched on STS-74 in 1995. Rassvet is primarily used for cargo storage and as a docking port for visiting spacecraft. It was flown to the ISS aboard NASA's Space Shuttle Atlantis on the STS-132 mission and connected in May 2010,[116][117] Rassvet is the only Russian owned module launched by NASA, to repay for the launch of Zarya, which is Russian designed and built, but partially paid for by NASA.[118] Rassvet was launched with the Russian Nauka Laboratory's Experiments airlock temporarily attached to it, and spare parts for the European Robotic Arm.
Leonardo Permanent Multipurpose Module (PMM) is a storage module attached to the Unity node.[119] The three NASA Space Shuttle MPLM cargo containers Leonardo, Raffaello and Donatello, were built for NASA in Turin, Italy by Alcatel Alenia Space, now Thales Alenia Space.[120] The MPLMs are provided to the ISS programme by the Italy (independent of Italy's role as a member state of ESA) to NASA and are considered to be US elements. In a bartered exchange for providing these containers, the U.S. has given Italy research time aboard the ISS out of the US allotment in addition to that which Italy receives as a member of ESA.[121] The Permanent Multipurpose Module was created by converting Leonardo into a module that could be permanently attached to the station.[122][123][124]
Scheduled additional modules
Nauka (Russian: Нау́ка; lit. Science), also known as the Multipurpose Laboratory Module (MLM) or FGB-2, (Russian: Многофункциональный лабораторный модуль, or МЛМ), is the major Russian laboratory module. It is scheduled to arrive at the station in 2014, docking to the port currently occupied by the Pirs module.[125] Prior to the arrival of the Nauka module, a Progress spacecraft will be used to remove Pirs from the station, deorbiting it to reenter over the Pacific Ocean. Nauka contains an additional set of life support systems and attitude control. Originally it would have routed power from the single Science-and-Power Platform, but that single module design changed over the first ten years of the ISS mission, and the two science modules, which attach to Nauka via the Uzlovoy Module, or Russian node, each incorporate their own large solar arrays to power Russian science experiments in the ROS.
Nauka's mission has changed over time. During the mid-1990s, it was intended as a backup for the FGB, and later as a universal docking module (UDM); its docking ports will be able to support automatic docking of both spacecraft, additional modules and fuel transfer. Nauka is a module in the 20 ton[which?] class and has its own engines. Smaller Russian modules such as Pirs and Poisk were delivered by modified Progress spacecraft, however the larger modules; Zvezda Zarya and Nauka, are launched by Proton rockets. They are the only modules on the ISS that contain engines or navigation computers with star, sun and horizon sensors, to enable flight and station-keeping.[citation needed] Russia plans to separate Nauka, allong with the rest of the Russian Orbital Segment, before the ISS is deorbited, to form the OPSEK space station.
The Uzlovoy Module (UM), or Node Module is a 4-ton[which?] ball shaped module will support the docking of two scientific and power modules during the final stage of the station assembly and provide the Russian segment additional docking ports to receive Soyuz TMA (transportation modified anthropometric) and Progress M spacecraft. NM is to be incorporated into the ISS in 2014. It will be integrated with a special version of the Progress cargo ship and launched by a standard Soyuz rocket. The Progress would use its own propulsion and flight control system to deliver and dock the Node Module to the nadir (Earth-facing) docking port of the Nauka MLM/FGB-2 module. One port is equipped with an active hybrid docking port, which enables docking with the MLM module. The remaining five ports are passive hybrids, enabling docking of Soyuz and Progress vehicles, as well as heavier modules and future spacecraft with modified docking systems. However more importantly, the node module was conceived to serve as the only permanent element of the future Russian successor to the ISS, OPSEK. Equipped with six docking ports, the Node Module would serve as a single permanent core of the future station with all other modules coming and going as their life span and mission required.[126][127] This would be a progression beyond the ISS and Russia's modular MIR space station, which are in turn more advanced than early monolithic first generation stations such as Skylab, and early Salyut and Almaz stations.
Science Power Modules 1 & 2 (NEM-1, NEM-2) (Russian: Научно-Энергетический Модуль-1 и -2)
Bigelow Expandable Activity Module (BEAM) is part of a contract with Bigelow Aerospace to provide a Bigelow Expandable Activity Module (BEAM), which is scheduled to arrive at the space station in 2015 for a two-year technology demonstration.[128] BEAM is an inflatable module developed by Bigelow Aerospace will be attached to the International Space Station attached to the aft hatch of the port-side Tranquility module. During its two-year test run, instruments will measure its structural integrity and leak rate, along with temperature and radiation levels. The hatch leading into the module will remain mostly closed except for periodic visits by space station crew members for inspections and data collection. Following the test run, the module will be detached and jettisoned from the station.[129]
Cancelled components
The US Habitation Module would have served as the station's living quarters. Instead, the sleep stations are now spread throughout the station.[130] The US Interim Control Module and ISS Propulsion Module were intended to replace functions of Zvezda in case of a launch failure.[131] The Russian Universal Docking Module, to which the cancelled Russian Research modules and spacecraft would have docked.[132] The Russian Science Power Platform would have provided the Russian Orbital Segment with a power supply independent of the ITS solar arrays,[132] and two Russian Research Modules that were planned to be used for scientific research.[133]
Unpressurised elements
ISS Truss Components breakdown showing Trusses and all ORUs in situ
The ISS features a large number of external components that do not require pressurisation. The largest such component is the Integrated Truss Structure (ITS), to which the station's main solar arrays and thermal radiators are mounted.[134] The ITS consists of ten separate segments forming a structure 108.5 m (356 ft) long.[3]
The station in its complete form has several smaller external components, such as the six robotic arms, the three External Stowage Platforms (ESPs) and four ExPrESS Logistics Carriers (ELCs).[102][135] Whilst these platforms allow experiments (including MISSE, the STP-H3 and the Robotic Refueling Mission) to be deployed and conducted in the vacuum of space by providing electricity and processing experimental data locally, the platforms' primary function is to store Orbital Replacement Units (ORUs). ORUs are spare parts that can be replaced when the item either passes its design life or fails. Examples of ORUs include pumps, storage tanks, antennas and battery units. Such units are replaced either by astronauts during EVA or by robotic arms. While spare parts were routinely transported to and from the station via Space Shuttle resupply missions, there was a heavy emphasis on ORU transport once the NASA Shuttle approached retirement.[136] Several shuttle missions were dedicated to the delivery of ORUs, including STS-129,[137] STS-133[138] and STS-134.[139] As of January 2011, only one other mode of transportation of ORUs had been utilised – the Japanese cargo vessel HTV-2 – which delivered an FHRC and CTC-2 via its Exposed Pallet (EP).[140][dated info]
There are also smaller exposure facilities mounted directly to laboratory modules; the JEM Exposed Facility serves as an external 'porch' for the Japanese Experiment Module complex,[141] and a facility on the European Columbus laboratory provides power and data connections for experiments such as the European Technology Exposure Facility[142][143] and the Atomic Clock Ensemble in Space.[144] A remote sensing instrument, SAGE III-ISS, is due to be delivered to the station in 2014 aboard a Dragon capsule, and the NICER experiment in 2016.[145][146] The largest such scientific payload externally mounted to the ISS is the Alpha Magnetic Spectrometer (AMS), a particle physics experiment launched on STS-134 in May 2011, and mounted externally on the ITS. The AMS measures cosmic rays to look for evidence of dark matter and antimatter.[147]
Cranes and robotic arms
Canadarm2, the largest robotic arm on the ISS, has a mass of 1,800 kilograms and is used to dock and manipulate spacecraft and modules on the USOS, and hold crew members and equipment during EVAs.[148] The ROS does not require spacecraft or modules to be manipulated, as all spacecraft and modules dock automatically, and may be discarded the same way. Crew use the 2 Strela (Russian: Стрела; lit. Arrow) cargo cranes during EVAs for moving crew and equipment around the ROS. Each Strela crane has a mass of 45 kg. The Russian and Japanese laboratories both have airlocks and robotic arms.
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Dextre, like many of the station's experiments and robotic arms, can be operated from Earth and perform tasks while the crew sleeps.
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The Integrated Truss Structure serves as a base for the main remote manipulator system called the Mobile Servicing System (MSS). This consists of the Mobile Base System (MBS), the Canadarm2, and Dextre. Dextre is a 1,500 kg agile robotic manipulator with two 'arms' which have 7 degrees of movement each, a 'torso' which bends at the waist and rotates at the base, a tool holster, lights and video. Staff on earth can operate Dextre via remote control, performing work without crew intervention. The MBS rolls along rails built into some of the ITS segments to allow the arm to reach all parts of the United States segment of the station.[149] The MSS had its reach increased an Orbiter Boom Sensor System in May 2011, used to inspect tiles on the NASA shuttle, and converted for permanent station use. To gain access to the extreme extents of the Russian Segment the crew also placed a "Power Data Grapple Fixture" to the forward docking section of Zarya, so that the Canadarm2 may inchworm itself onto that point.[150]
The European Robotic Arm, which will service the Russian Orbital Segment, will be launched alongside the Multipurpose Laboratory Module in 2012.[151] The Japanese Experiment Module's Remote Manipulator System (JFM RMS), which services the JEM Exposed Facility,[152] was launched on STS-124 and is attached to the JEM Pressurised Module.[153]
Station systems
Life support
The critical systems are the atmosphere control system, the water supply system, the food supply facilities, the sanitation and hygiene equipment, and fire detection and suppression equipment. The Russian orbital segment's life support systems are contained in the Service Module Zvezda. Some of these systems are supplemented by equipment in the USOS. The MLM Nauka laboratory has a complete set of life support systems.
Atmospheric control systems
The atmosphere on board the ISS is similar to the Earth's.[154] Normal air pressure on the ISS is 101.3 kPa (14.7 psi);[155] the same as at sea level on Earth. An Earth-like atmosphere offers benefits for crew comfort, and is much safer than the alternative, a pure oxygen atmosphere, because of the increased risk of a fire such as that responsible for the deaths of the Apollo 1 crew.[156] Earth-like atmospheric conditions have been maintained on all Russian and Soviet spacecraft.[157]
Elektron units in the Zvezda service module.
The Elektron system aboard Zvezda and a similar system in Destiny generate oxygen aboard the station.[158] The crew has a backup option in the form of bottled oxygen and Solid Fuel Oxygen Generation (SFOG) canisters, a chemical oxygen generator system.[159] Carbon dioxide is removed from the air by the Vozdukh system in Zvezda. Other by-products of human metabolism, such as methane from the intestines and ammonia from sweat, are removed by activated charcoal filters.[159]
Part of the ROS atmosphere control system is the oxygen supply, triple-redundancy is provided by the Elektron unit, solid fuel generators, and stored oxygen. The Elektron unit is the primary oxygen supply, O
2 and H
2 are produced by electrolysis, with the H
2 being vented overboard. The 1 kW system uses approximately 1 litre of water per crew member per day from stored water from Earth, or water recycled from other systems. MIR was the first spacecraft to use recycled water for oxygen production. The secondary oxygen supply is provided by burning O
2-producing Vika cartridges (see also ISS ECLSS). Each 'candle' takes 5–20 minutes to decompose at 450–500 °C, producing 600 litres of O
2. This unit is manually operated.[160]
The US orbital segment has redundant supplies of oxygen, from a pressurised storage tank on the Quest airlock module delivered in 2001, supplemented ten years later by ESA built Advanced Closed-Loop System (ACLS) in the Tranquility module (Node 3), which produces O
2 by electrolysis.[161] Hydrogen produced is combined with carbon dioxide from the cabin atmosphere and converted to water and methane.
Food
Most of the food on board is vacuum sealed in plastic bags. Cans are too heavy and expensive to transport, so there are not as many. The preserved food is generally not held in high regard by the crew, and when combined with the reduced sense of taste in a microgravity environment,[162] a great deal of effort is made to make the food more palatable. More spices are used than in regular cooking, and the crew looks forward to the arrival of any ships from Earth, as they bring fresh fruit and vegetables with them. Care is taken that foods do not create crumbs. Sauces are often used to ensure station equipment is not contaminated. Each crew member has individual food packages and cooks them using the on-board galley. The galley features two food warmers, a refrigerator added in November 2008, and a water dispenser that provides both heated and unheated water.[163] Drinks are provided in dehydrated powder form and are mixed with water before consumption.[163][164] Drinks and soups are sipped from plastic bags with straws, while solid food is eaten with a knife and fork, which are attached to a tray with magnets to prevent them from floating away. Any food that does float away, including crumbs, must be collected to prevent it from clogging up the station's air filters and other equipment.[164]
Hygiene
Showers on space stations were introduced in the early 1970s on Skylab and Salyut 3.[165]:139 By Salyut 6, in the early 1980s, the crew complained of the complexity of showering in space, which was a monthly activity. The ISS does not feature a shower; instead, crewmembers wash using a water jet and wet wipes, with soap dispensed from a toothpaste tube-like container. Crews are also provided with rinseless shampoo and edible toothpaste to save water.[166][167]
There are two space toilets on the ISS, both of Russian design, located in Zvezda and Tranquility.[163] These Waste and Hygiene Compartments use a fan-driven suction system similar to the Space Shuttle Waste Collection System. Astronauts first fasten themselves to the toilet seat, which is equipped with spring-loaded restraining bars to ensure a good seal.[162] A lever operates a powerful fan and a suction hole slides open: the air stream carries the waste away. Solid waste is collected in individual bags which are stored in an aluminium container. Full containers are transferred to Progress spacecraft for disposal.[163][168] Liquid waste is evacuated by a hose connected to the front of the toilet, with anatomically correct "urine funnel adapters" attached to the tube so both men and women can use the same toilet. Waste is collected and transferred to the Water Recovery System, where it is recycled back into drinking water.[164]
| Author: | Bling King |
| Published: | Sep 9th 2013 |
| Modified: | Sep 9th 2013 |
