Topics: Space Exploration - 2. International Space Station

2. International Space Station

The International Space Station is the largest and most complex international scientific project in history. And when it is complete just after the turn of the century, the the station will represent a move of unprecedented scale off the home planet. Led by the United States, the International Space Station draws upon the scientific and technological resources of 16 nations: Canada, Japan, Russia, 11 nations of the European Space Agency and Brazil.

More than four times as large as the Russian Mir space station, the completed International Space Station will have a mass of about 1,040,000 pounds. It will measure 356 feet across and 290 feet long, with almost an acre of solar panels to provide electrical power to six state-of-the-art laboratories.

The station will be in an orbit with an altitude of 250 statute miles with an inclination of 51.6 degrees. This orbit allows the station to be reached by the launch vehicles of all the international partners to provide a robust capability for the delivery of crews and supplies. The orbit also provides excellent Earth observations with coverage of 85 percent of the globe and over flight of 95 percent of the population. By the end of this year, about 500,000 pounds of station components will be have been built at factories around the world.

U.S. Role and Contributions

The United States has the responsibility for developing and ultimately operating major elements and systems aboard the station. The U.S. elements include three connecting modules, or nodes; a laboratory module; truss segments; four solar arrays; a habitation module; three mating adapters; a cupola; an unpressurized logistics carrier and a centrifuge module. The various systems being developed by the U.S. include thermal control; life support; guidance, navigation and control; data handling; power systems; communications and tracking; ground operations facilities and launch-site processing facilities.

International Contributions

The international partners, Canada, Japan, the European Space Agency, and Russia, will contribute the following key elements to the International Space Station:

· Canada is providing a 55-foot-long robotic arm to be used for assembly and maintenance tasks on the Space Station.

· The European Space Agency is building a pressurized laboratory to be launched on the Space Shuttle and logistics transport vehicles to be launched on the Ariane 5 launch vehicle.

· Japan is building a laboratory with an attached exposed exterior platform for experiments as well as logistics transport vehicles.

· Russia is providing two research modules; an early living quarters called the Service Module with its own life support and habitation systems; a science power platform of solar arrays that can supply about 20 kilowatts of electrical power; logistics transport vehicles; and Soyuz spacecraft for crew return and transfer.

In addition, Brazil and Italy are contributing some equipment to the station through agreements with the United States.

ISS Phase One: The Shuttle-Mir Program

The first phase of the International Space Station, the Shuttle-Mir Program, began in 1995 and involved more than two years of continuous stays by astronauts aboard the Russian Mir Space Station and nine Shuttle-Mir docking missions. Knowledge was gained in technology, international space operations and scientific research.

Seven U.S. astronauts spent a cumulative total of 32 months aboard Mir with 28 months of continuous occupancy since March 1996. By contrast, it took the U.S. Space Shuttle fleet more than a dozen years and 60 flights to achieve an accumulated one year in orbit. Many of the research programs planned for the International Space Station benefit from longer stay times in space. The U.S. science program aboard the Mir was a pathfinder for more ambitious experiments planned for the new station.

For less than two percent of the total cost of the International Space Station program, NASA gained knowledge and experience through Shuttle-Mir that could not be achieved any other way. That included valuable experience in international crew training activities; the operation of an international space program; and the challenges of long duration spaceflight for astronauts and ground controllers. Dealing with the real-time challenges experienced during Shuttle-Mir missions also has resulted in an unprecedented cooperation and trust between the U.S. and Russian space programs, and that cooperation and trust has enhanced the development of the International Space Station.

The International Space Station will establish an unprecedented state-of-the-art laboratory complex in orbit, more than four times the size and with almost 60 times the electrical power for experiments — critical for research capability — of Russia's Mir. Research in the station's six laboratories will lead to discoveries in medicine, materials and fundamental science that will benefit people all over the world. Through its research and technology, the station also will serve as an indispensable step in preparation for future human space exploration.

Examples of the types of U.S. research that will be performed aboard the station include:

· Protein crystal studies: More pure protein crystals may be grown in space than on Earth. Analysis of these crystals helps scientists better understand the nature of proteins, enzymes and viruses, perhaps leading to the development of new drugs and a better understanding of the fundamental building blocks of life. Similar experiments have been conducted on the Space Shuttle, although they are limited by the short duration of Shuttle flights. This type of research could lead to the study of possible treatments for cancer, diabetes, emphysema and immune system disorders, among other research.

· Tissue culture: Living cells can be grown in a laboratory environment in space where they are not distorted by gravity. NASA already has developed a Bioreactor device that is used on Earth to simulate, for such cultures, the effect of reduced gravity. Still, these devices are limited by gravity. Growing cultures for long periods aboard the station will further advance this research. Such cultures can be used to test new treatments for cancer without risking harm to patients, among other uses.

· Life in low gravity: The effects of long-term exposure to reduced gravity on humans – weakening muscles; changes in how the heart, arteries and veins work; and the loss of bone density, among others – will be studied aboard the station. Studies of these effects may lead to a better understanding of the body’s systems and similar ailments on Earth. A thorough understanding of such effects and possible methods of counteracting them is needed to prepare for future long-term human exploration of the solar system. In addition, studies of the gravitational effects on plants, animals and the function of living cells will be conducted aboard the station. A centrifuge, located in the Centrifuge Accommodation Module, will use centrifugal force to generate simulated gravity ranging from almost zero to twice that of Earth. This facility will imitate Earth’s gravity for comparison purposes; eliminate variables in experiments; and simulate the gravity on the Moon or Mars for experiments that can provide information useful for future space travels.

· Flames, fluids and metal in space: Fluids, flames, molten metal and other materials will be the subject of basic research on the station. Even flames burn differently without gravity. Reduced gravity reduces convection currents, the currents that cause warm air or fluid to rise and cool air or fluid to sink on Earth. This absence of convection alters the flame shape in orbit and allows studies of the combustion process that are impossible on Earth, a research field called Combustion Science. The absence of convection allows molten metals or other materials to be mixed more thoroughly in orbit than on Earth. Scientists plan to study this field, called Materials Science, to create better metal alloys and more perfect materials for applications such as computer chips. The study of all of these areas may lead to developments that can enhance many industries on Earth.

· The nature of space: Some experiments aboard the station will take place on the exterior of the station modules. Such exterior experiments can study the space environment and how long-term exposure to space, the vacuum and the debris, affects materials. This research can provide future spacecraft designers and scientists a better understanding of the nature of space and enhance spacecraft design. Some experiments will study the basic forces of nature, a field called Fundamental Physics, where experiments take advantage of weightlessness to study forces that are weak and difficult to study when subject to gravity on Earth. Experiments in this field may help explain how the universe developed. Investigations that use lasers to cool atoms to near absolute zero may help us understand gravity itself. In addition to investigating basic questions about nature, this research could lead to down-to-Earth developments that may include clocks a thousand times more accurate than today’s atomic clocks; better weather forecasting; and stronger materials.

· Watching the Earth: Observations of the Earth from orbit help the study of large-scale, long-term changes in the environment. Studies in this field can increase understanding of the forests, oceans and mountains. The effects of volcanoes, ancient meteorite impacts, hurricanes and typhoons can be studied. In addition, changes to the Earth that are caused by the human race can be observed. The effects of air pollution, such as smog over cities; of deforestation, the cutting and burning of forests; and of water pollution, such as oil spills, are visible from space and can be captured in images that provide a global perspective unavailable from the ground.

· Commercialization: As part of the Commercialization of space research on the station, industries will participate in research by conducting experiments and studies aimed at developing new products and services. The results may benefit those on Earth not only by providing innovative new products as a result, but also by creating new jobs to make the products.

Assembly in Orbit

By the end of this year, most of the components required for the first seven Space Shuttle missions to assemble the International Space Station will have arrived at the Kennedy Space Center. The first and primary fully Russian contribution to the station, the Service Module, is scheduled to be shipped from Moscow to the Kazakstan launch site in February 1999.

Orbital assembly of the International Space Station will begin a new era of hands-on work in space, involving more spacewalks than ever before and a new generation of space robotics. About 850 clock hours of spacewalks, both U.S. and Russian, will be required over five years to maintain and assemble the station. The Space Shuttle and two types of Russian launch vehicles will launch 45 assembly missions. Of these, 36 will be Space Shuttle flights. In addition, resupply missions and changeouts of Soyuz crew return spacecraft will be launched regularly.

The first crew to live aboard the International Space Station, commanded by U.S. astronaut Bill Shepherd and including Russian cosomonauts Yuri Gidzenko as Soyuz Commander and Sergei Krikalev as Flight Engineer, will be launched in early 2000 on a Russian Soyuz spacecraft. They, along with the crews of the first five assembly missions, are now in training. The timetable and sequence of flights for assembly, beyond the first two, will be further refined at a meeting of all the international partners in December 1998. Assembly is planned to be complete by 2004.


International Space Station

by Wikipedia

The International Space Station (ISS) is an internationally developed research facility currently being assembled in Low Earth Orbit. On-orbit construction of the station began in 1998 and is scheduled to be complete by 2011, with operations continuing until at least 2015.[6] The ISS orbits at an altitude of approximately 350 kilometers (220 mi) above the surface of the Earth,[7][8][9] travelling at an average speed of 27,724 kilometers (17,227 mi) per hour and completing 15.7 orbits per day.[7] The station can be seen from the Earth with the naked eye,[10] and, as of 2009[update], is the largest artificial satellite in Earth orbit with a mass larger than that of any previous space station.[11]

The ISS is a joint project among the space agencies of multiple nations. These consist of the United States National Aeronautics and Space Administration (NASA), Russian Federal Space Agency (RKA), Japan Aerospace Exploration Agency (JAXA), Canadian Space Agency (CSA) and the European Space Agency (ESA) of ten European nations.[12][a] The Brazilian Space Agency (AEB) participates through a separate contract with NASA.[13] The Italian Space Agency (ASI) has separate contracts for various activities not done within the framework of ESA's ISS projects, where Italy is a full participant.[14] China has reportedly expressed interest in the project, especially if it would be able to work with the RKA. However, as of 2009[update] China is not involved because of objections from the United States.[15][16]

The ISS has been continuously staffed since the first resident crew, Expedition 1, entered the station on 2 November 2000. This has provided an uninterrupted human presence in space for the last 8 years, 329 days.[17] Prior to May 2009, the station had the capacity for a crew of three. Since the arrival of Expedition 20, it has been staffed by a resident crew of six and can fulfil an active research programme. The crew of Expedition 20 is currently aboard.[18][19] Resident crews utilise the station as an orbital laboratory to carry out research across a wide variety of fields, including biology, human biology, physics, astronomy and meteorology.[20][21] The station provides a safe testing location for efficient, reliable spacecraft systems that will be required for long-duration missions to the Moon and Mars.[22]

The station consists of several pressurised modules and unpressurised components, which have been launched by Space Shuttle, Soyuz rocket or Proton rocket. The ISS is serviced by a wide variety of manned and unmanned spacecraft, including the Soyuz spacecraft, Progress spacecraft, Space Shuttle, Automated Transfer Vehicle, and H-II Transfer Vehicle, and has been visited by astronauts and cosmonauts from 16 different nations. The various sections of the station are controlled by several mission control centres on the ground, including MCC-H, TsUP, Col-CC, ATV-CC, JEM-CC, HTV-CC and MSS-CC.[23]


The International Space Station serves primarily as a research laboratory and is the largest satellite ever launched into orbit.[11] The station offers an advantage over spacecraft such as NASA's Space Shuttle because it is a long-term platform in the space environment, allowing long-duration studies to be performed, both on specific experiments and on the human crews that operate them.[9] The presence of a permanent crew also means that the station offers benefits over unmanned spacecraft as experiments can be monitored, replenished, repaired or replaced as required by the crew, as can various other components of the spacecraft itself. This means that scientists on the ground have swift access to their data and can modify experiments or fly new ones as and when required, benefits generally unavailable on specialized unmanned spacecraft.[9]

Crews flying long-term expeditions, lasting several months, conduct science daily (approximately 160 man-hours a week)[24] across a wide variety of fields, including human research (space medicine), life sciences, physical sciences, and Earth observation, as well as education and technology demonstrations.[25] As of the conclusion of Expedition 15, 138 major science investigations had been conducted on the ISS since the launch of Zarya in 1998.[26] Scientific findings, in fields ranging from basic science to exploration research, are being published every month.[22].

The ISS also provides a testing location for efficient, reliable spacecraft systems that will be required for long-duration missions to the Moon and Mars, allowing for equipment to be evaluated in the relatively safe location of Low Earth Orbit. This provides experience in maintaining, repairing, and replacing systems on-orbit, which will be essential in operating spacecraft further from Earth. This aspect of ISS operations reduces mission risks, and advances the capabilities of interplanetary spacecraft.[22]

Finally, in addition to the scientific and research aspects of the station, there are numerous opportunities for educational outreach and international cooperation. The crews of the ISS provide educational opportunities for students back home on Earth, including student-developed experiments, educational demonstrations, student participation in classroom versions of ISS experiments, NASA investigator experiments, and ISS engineering activities. The ISS programme itself, and the international cooperation that it represents, allows 14 nations to live and work together in space, providing important lessons that can be taken forward into future multi-national missions.[27]

Scientific research

Side by side images of a candle flame (left) and a glowing translucent blue hemisphere of flame (right).

A comparison between fire on Earth (left) and fire in a microgravity environment (right), such as that found on the ISS.

One of the main goals of the ISS is to provide a place to conduct experiments that require one or more of the unusual conditions present on the station. The primary fields of research include biology, physics, astronomy, and meteorology.[20][21] The 2005 NASA Authorization Act designated the US segment of the International Space Station as a national laboratory with a goal to increase the use of the ISS by other Federal entities and the private sector.[28]

One research goal is to improve the understanding of long-term space exposure on the human body. Subjects currently under study include muscle atrophy, bone loss, and fluid shift. The data will be used to determine whether space colonisation and lengthy human spaceflight are feasible. As of 2006, data on bone loss and muscular atrophy suggest that there would be a significant risk of fractures and movement problems if astronauts landed on a planet following a lengthy space cruise.[29]

Researchers are investigating the relation of the near-weightless environment on the ISS to the evolution, development and growth, and the internal processes of plants and animals. In response to some of this data, NASA wants to investigate microgravity's effects on the growth of three-dimensional, human-like tissues, and the unusual protein crystals that can be formed in space.[20]

The physics of fluids in microgravity is being investigated, enabling researchers to better model the behaviour of fluids in the future. Because of the ability to almost completely combine fluids in microgravity, physicists are interested in investigating the combinations of fluids that will not normally mix well on Earth. In addition, by examining reactions that are slowed down by low gravity and temperatures, scientists hope to gain new insight regarding superconductivity.[20]

Materials science is an important part of the research activity aboard the station, with the goal of reaping economic benefits by improving techniques used on the ground. Experiments are intended to provide a better understanding of the relationship between processing, structure, and properties so the conditions required on Earth to achieve desired materials properties can be reliably predicted.[30]

Other areas of interest include the effect of the low gravity environment on combustion, studying the efficiency of burning and control of emissions and pollutants. These findings may improve our understanding of energy production, and in turn have an economic and environmental impact. There are also plans to use the ISS to examine aerosols, ozone, water vapour, and oxides in Earth's atmosphere, as well as cosmic rays, cosmic dust, antimatter, and dark matter in the universe.[20]

One component assisting in these various studies is the ExPRESS Logistics Carrier (ELC). Developed by NASA, four of these units are set to be launched to the ISS. As currently envisioned, the ELCs will be delivered on three separate Space Shuttle missions. They will allow experiments to be deployed and conducted in the vacuum of space, and will provide the necessary electricity and computing to process experimental data locally. Delivery is currently scheduled for STS-129 in November 2009, STS-134 in May 2010 and STS-133 in September 2010.[31]

The Alpha Magnetic Spectrometer (AMS), a particle physics experiment, is scheduled to be added to the station. This device will be launched on STS-134 in 2010, and will be mounted externally on the Integrated Truss Structure. The AMS will search for various types of unusual matter by measuring cosmic rays. The experiments conducted will help researchers study the formation of the universe, and search for evidence of dark matter and antimatter.[32]


A cluster of cylindrical modules with projecting feathery solar arrays and a space shuttle docked to the lower module. In the background is the blackness of space, and, in the lower right corner, Earth.

Space Shuttle Atlantis docked to Mir on STS-71, during the Shuttle-Mir Programme

Originating during the Cold War, the International Space Station represents a union of several space station projects from various nations. During the early 1980s, NASA had planned to launch a modular space station called Freedom as a counterpart to the Soviet Salyut and Mir space stations. In addition, the Soviets were planning a replacement for Mir to be constructed during the 1990s called Mir-2.[33] Because of budget and design constraints, however, Freedom never progressed past mock-ups and minor component tests.

With the fall of the Soviet Union ending the Cold War and Space Race, Freedom was nearly cancelled by the United States House of Representatives. The post-Soviet economic chaos in Russia also led to the eventual cancellation of Mir-2, with only the base block of that station, DOS-8, having been constructed.[33] Similar difficulties were being faced by the U.S. and other nations with plans for space stations. This prompted U.S. administration officials to start negotiations with partners in Europe, Russia, Japan, and Canada in the early 1990s to begin a collaborative, multi-national, space station project.[33]

In June 1992, then U.S. president George H. W. Bush and Russian president Boris Yeltsin agreed to cooperate on space exploration by signing the Agreement between the United States of America and the Russian Federation Concerning Cooperation in the Exploration and Use of Outer Space for Peaceful Purposes. This agreement called for setting up a short, joint space programme, during which one U.S. astronaut would board the Russian space station Mir and two Russian cosmonauts would board a space shuttle.[33]

In September 1993, U.S. Vice-president Al Gore and Russian Prime Minister Viktor Chernomyrdin announced plans for a new space station, which eventually became the International Space Station.[34] They also agreed, in preparation for this new project, that the US would be heavily involved in the Mir programme in the years ahead, as part of an agreement that later included Space Shuttle orbiters docking with Mir.[35]

The ISS programme was planned to combine the proposed space stations of all participating space agencies, including Freedom, Mir-2 (with DOS-8 later becoming Zvezda), ESA's Columbus, and the Japanese KibÅ

2. International Space Station