Researchers are investigating the effect of the station's near-weightless environment on the evolution, development, growth and internal processes of plants and animals. Sex is based on anatomy, whereas gender accounts for how a person feels and identifies. Archived from the original PDF on 30 August
The Dragon spacecraft allows the return of pressurised cargo to Earth downmass , which is used for example to repatriate scientific experiments for further analysis. The Soyuz return capsule has minimal downmass capability next to the astronauts. It was also planned to provide transportation, maintenance, and act as a staging base for possible future missions to the Moon, Mars and asteroids.
The ISS provides a platform to conduct scientific research. Small unmanned spacecraft can provide platforms for zero gravity and exposure to space, but space stations offer a long-term environment where studies can be performed potentially for decades, combined with ready access by human researchers over periods that exceed the capabilities of manned spacecraft.
The ISS simplifies individual experiments by eliminating the need for separate rocket launches and research staff. The wide variety of research fields include astrobiology , astronomy , human research including space medicine and life sciences , physical sciences , materials science , space weather , and weather on Earth meteorology.
To detect dark matter and answer other fundamental questions about our universe, engineers and scientists from all over the world built the Alpha Magnetic Spectrometer AMS , which NASA compares to the Hubble Space Telescope , and says could not be accommodated on a free flying satellite platform partly because of its power requirements and data bandwidth needs.
The space environment is hostile to life. Unprotected presence in space is characterised by an intense radiation field consisting primarily of protons and other subatomic charged particles from the solar wind , in addition to cosmic rays , high vacuum, extreme temperatures, and microgravity. Medical research improves knowledge about the effects of long-term space exposure on the human body, including muscle atrophy , bone loss , and fluid shift.
This data will be used to determine whether lengthy human spaceflight and space colonisation are feasible. As of [update] , 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 after a lengthy interplanetary cruise, such as the six-month interval required to travel to Mars.
Prominent among these is the Advanced Diagnostic Ultrasound in Microgravity study in which astronauts perform ultrasound scans under the guidance of remote experts. The study considers the diagnosis and treatment of medical conditions in space. Usually, there is no physician on board the ISS and diagnosis of medical conditions is a challenge. It is anticipated that remotely guided ultrasound scans will have application on Earth in emergency and rural care situations where access to a trained physician is difficult.
Researchers are investigating the effect of the station's near-weightless environment on the evolution, development, growth and 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. Investigating the physics of fluids in microgravity will provide better models of the behaviour of fluids. Because fluids can be almost completely combined in microgravity, physicists investigate fluids that do not mix well on Earth.
In addition, examining reactions that are slowed by low gravity and low temperatures will improve our understanding of superconductivity.
The study of materials science is an important ISS research activity, with the objective of reaping economic benefits through the improvement of techniques used on the ground. These findings may improve current knowledge about energy production, and lead to economic and environmental benefits.
Future plans are for the researchers aboard 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. The ISS provides a location in the relative safety of Low Earth Orbit to test spacecraft systems that will be required for long-duration missions to the Moon and Mars. This provides experience in operations, maintenance as well as repair and replacement activities on-orbit, which will be essential skills in operating spacecraft farther from Earth, mission risks can be reduced and the capabilities of interplanetary spacecraft advanced.
In , noting the value of the partnership framework itself, Sergey Krasnov wrote, "When compared with partners acting separately, partners developing complementary abilities and resources could give us much more assurance of the success and safety of space exploration. The ISS is helping further advance near-Earth space exploration and realisation of prospective programmes of research and exploration of the Solar system, including the Moon and Mars.
The ISS crew provides opportunities for students on Earth by running student-developed experiments, making educational demonstrations, allowing for student participation in classroom versions of ISS experiments, and directly engaging students using radio, videolink and email.
JAXA aims both to "Stimulate the curiosity of children, cultivating their spirits, and encouraging their passion to pursue craftsmanship", and to "Heighten the child's awareness of the importance of life and their responsibilities in society. Students grow sunflower seeds which flew on the ISS for about nine months as a start to 'touch the Universe'. Cultural activities are another major objective.
Amateur Radio on the ISS ARISS is a volunteer programme which encourages students worldwide to pursue careers in science, technology, engineering and mathematics through amateur radio communications opportunities with the ISS crew. In areas where radio equipment cannot be used, speakerphones connect students to ground stations which then connect the calls to the station.
First Orbit is a feature-length documentary film about Vostok 1 , the first manned space flight around the Earth. By matching the orbit of the International Space Station to that of Vostok 1 as closely as possible, in terms of ground path and time of day, documentary filmmaker Christopher Riley and ESA astronaut Paolo Nespoli were able to film the view that Yuri Gagarin saw on his pioneering orbital space flight.
This new footage was cut together with the original Vostok 1 mission audio recordings sourced from the Russian State Archive. These were the first content made specifically for Wikipedia, in space. The assembly of the International Space Station, a major endeavour in space architecture , began in November It provided propulsion, attitude control , communications, electrical power, but lacked long-term life support functions.
At that time, the Russian station Mir was still inhabited. The ISS remained unmanned for two years, while Mir was de-orbited. On 12 July , Zvezda was launched into orbit. Preprogrammed commands on board deployed its solar arrays and communications antenna. It then became the passive target for a rendezvous with Zarya and Unity: Zarya 's computer transferred control of the station to Zvezda 's computer soon after docking.
Zvezda added sleeping quarters, a toilet, kitchen, CO 2 scrubbers, dehumidifier, oxygen generators, exercise equipment, plus data, voice and television communications with mission control. This enabled permanent habitation of the station. At the end of the first day on the station, astronaut Bill Shepherd requested the use of the radio call sign " Alpha ", which he and cosmonaut Krikalev preferred to the more cumbersome " International Space Station ".
Referencing a naval tradition in a pre-launch news conference he had said: People have designed and built these vessels, launched them with a good feeling that a name will bring good fortune to the crew and success to their voyage.
These two Space Shuttle flights each added segments of the station's Integrated Truss Structure , which provided the station with Ku-band communication for US television, additional attitude support needed for the additional mass of the USOS, and substantial solar arrays supplementing the station's existing 4 solar arrays. Over the next two years, the station continued to expand. A Soyuz-U rocket delivered the Pirs docking compartment. The Space Shuttles Discovery , Atlantis , and Endeavour delivered the Destiny laboratory and Quest airlock , in addition to the station's main robot arm, the Canadarm2 , and several more segments of the Integrated Truss Structure.
The expansion schedule was interrupted by the Space Shuttle Columbia disaster in and a resulting two-year hiatus in the Space Shuttle programme. The space shuttle was grounded until with STS flown by Discovery. Assembly resumed in with the arrival of STS with Atlantis , which delivered the station's second set of solar arrays. As a result of the major expansion of the station's power-generating capabilities, more pressurised modules could be accommodated, and the Harmony node and Columbus European laboratory were added.
After the Nauka module is attached, the Uzlovoy Module will be attached to one of its docking ports. When completed, the station will have a mass of more than tonnes short tons. The gross mass of the station changes over time. Hydrogen gas is constantly vented overboard by the oxygen generators.
The ISS is a third generation  modular space station. Below is a diagram of major station components. The blue areas are pressurised sections accessible by the crew without using spacesuits. The station's unpressurised superstructure is indicated in red.
Other unpressurised components are yellow. Note that the Unity node joins directly to the Destiny laboratory. For clarity, they are shown apart. The ISS follows Salyut and Almaz series, Skylab , and Mir as the 11th space station launched, as the Genesis prototypes were never intended to be manned. Salyut 6 and 7 had more than one docking port and were designed to be resupplied routinely during crewed operation.
With the launch and assembly in orbit of other modules with more specialised functionality, Zarya is now primarily used for storage, both inside the pressurised section and in the externally mounted fuel tanks. The name Zarya was given to the FGB because it signified the dawn of a new era of international co-operation in space.
Although it was built by a Russian company, it is owned by the United States. The control system was developed by the Ukrainian Khartron corporation in Kharkiv. Although only designed to fly autonomously for six to eight months, Zarya did so for almost two years because of delays with the Russian Service Module, Zvezda , which finally launched on 12 July , and docked with Zarya on 26 July using the Russian Kurs docking system.
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.
The module is made of aluminium and cylindrical in shape, with six berthing locations facilitating connections to other modules. Essential space station resources such as fluids, environmental control and life support systems, electrical and data systems are routed through Unity to supply work and living areas of the station.
More than 50, mechanical items, lines to carry fluids and gases, and internal and external electrical cables using six miles of wire were installed in the Unity node. The adapters allow the docking systems used by the Space Shuttle and by Russian modules to attach to the node's hatches and berthing mechanisms. Unity was carried into orbit by Space Shuttle Endeavour in as the primary cargo of STS , the first Space Shuttle mission dedicated to assembly of the station. On 6 December , the STS crew mated the aft berthing port of Unity with the forward hatch of the already orbiting Zarya module.
Early in the station's life, Zvezda provided all of its critical systems. Initially built to be the core of the cancelled Mir-2 space station, the hull of Zvezda was completed in February , with major internal equipment installed by October Zvezda is at the rear of the station according to its normal direction of travel and orientation, and its engines may be 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 , also known as the U. 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. It consists of two segments: 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.
Pirs and Poisk are Russian airlock modules, each having 2 identical hatches. An outward-opening hatch on the Mir space station failed after it swung open too fast after unlatching, because of a small amount of air pressure remaining in the airlock. Pirs was used to store, service, and refurbish Russian Orlan suits and provided 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. Harmony , also known as Node 2, 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 nadir and zenith ports can be used for docking visiting spacecraft including HTV, Dragon, and Cygnus, with the nadir port serving as the primary docking port. Tranquility , also known as Node 3, 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.
Like the other US nodes, it has six berthing mechanisms, five of which are currently in use. The final zenith port remains free. 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.
A number of expansions are planned for the module to study quantum physics and cosmology. It is used for research in space medicine, biology, Earth observations, materials production, biotechnology and communications, and has facilities for growing plants and fish.
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 EVAs.
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. Japanese ground controllers use telepresence robotics to remotely conduct onboard research and experiments, thus reducing the workload of station astronauts.
Ground controllers also use a free-floating autonomous ball camera to photodocument astronaut and space station activities, further freeing up astronaut time. 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 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. The distinctive design has been compared to the 'turret' of the fictitious Millennium Falcon from the motion picture Star Wars ;   the original prop lightsaber used by actor Mark Hamill as Luke Skywalker in the film was flown to the station in Rassvet is primarily used for cargo storage and for docking by visiting spacecraft.
During its two-year test run, instruments are measuring its structural integrity and leak rate, along with temperature and radiation levels. The hatch leading into the module remains closed except for periodic visits by space station crew members for inspections and data collection.
The module was originally planned to be jettisoned from the station following the test,  but following positive data after a year in orbit, NASA has suggested that it could remain on the station as a storage area.
It was attached and connected to PMA-2 during a spacewalk on 19 August It was scheduled to arrive at the station in , docking to the port that was occupied by the Pirs module. 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 mids, 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 has its own engines. Like Zvezda and Zarya , Nauka will be launched by a Proton rocket, while smaller Russian modules such as Pirs and Poisk were delivered by modified Progress spacecraft. The Uzlovoy Module UM , or Node Module is a 4-metric-ton  ball-shaped module that will allow 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 MS and Progress MS spacecraft.
UM is due to be launched in late It will be integrated with a special version of the Progress cargo ship and launched by a standard Soyuz rocket. 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. 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.
IDA-3 is being built mostly from spare parts to speed construction. The NanoRacks Airlock Module is a commercially -funded airlock module intended to be launched in It is intended to be manifested with a Commercial Resupply Services mission.
Several modules planned for the station were cancelled over the course of the ISS programme. Reasons include budgetary constraints, the modules becoming unnecessary, and station redesigns after the Columbia disaster. The US Centrifuge Accommodations Module would have hosted science experiments in varying levels of artificial gravity.
Instead, the sleep stations are now spread throughout the station. The ISS has a large number of external components that do not require pressurisation. The largest of these is the Integrated Truss Structure ITS , to which the station's main solar arrays and thermal radiators are mounted. ORUs are parts that can be replaced when they fail or pass their design life. Examples of ORUs include pumps, storage tanks, antennas and battery units.
Such units are replaced either by astronauts during EVA or by robotic arms. The AMS measures cosmic rays to look for evidence of dark matter and antimatter. The system is designed to be robotically serviced and will require no astronaut intervention. It is named after Christopher Columbus's younger brother. The Integrated Truss Structure serves as a base for the station's primary remote manipulator system, called the Mobile Servicing System MSS , which is composed of three main components.
Crew use the two Strela Russian: 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 Zvezda service module. Some of these systems are supplemented by equipment in the USOS. The MLM Nauka laboratory has a complete set of life support systems. The atmosphere on board the ISS is similar to the Earth's. An Earth-like atmosphere offers benefits for crew comfort, and is much safer than a pure oxygen atmosphere, because of the increased risk of a fire such as that responsible for the deaths of the Apollo 1 crew.
The Elektron system aboard Zvezda and a similar system in Destiny generate oxygen aboard the station. Other by-products of human metabolism, such as methane from the intestines and ammonia from sweat, are removed by activated charcoal filters. 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 primary supply of oxygen is the Elektron unit which produces O 2 and H 2 by electrolysis of water and vents H2 overboard. This water is either brought from Earth or recycled from other systems. Mir was the first spacecraft to use recycled water for oxygen production. This unit is manually operated. Double-sided solar, or Photovoltaic , arrays provide electrical power for the ISS.
These bifacial cells are more efficient and operate at a lower temperature than single-sided cells commonly used on Earth, by collecting sunlight on one side and light reflected off the Earth on the other. The higher distribution voltage allows smaller, lighter conductors, at the expense of crew safety. The ROS uses low voltage ; the two station segments share power with converters. The USOS solar arrays are arranged as four wing pairs, for a total production of 75 to 90 kilowatts.
In the complete configuration, the solar arrays track the sun by rotating the alpha gimbal once per orbit; the beta gimbal follows slower changes in the angle of the sun to the orbital plane. The Night Glider mode aligns the solar arrays parallel to the ground at night to reduce the significant aerodynamic drag at the station's relatively low orbital altitude. The station uses rechargeable nickel—hydrogen batteries NiH 2 for continuous power during the 35 minutes of every minute orbit that it is eclipsed by the Earth.
The batteries are recharged on the day side of the Earth. They have a 6. The station's large solar panels generate a high potential voltage difference between the station and the ionosphere. This could cause arcing through insulating surfaces and sputtering of conductive surfaces as ions are accelerated by the spacecraft plasma sheath. To mitigate this, plasma contactor units PCU s create current paths between the station and the ambient plasma field.
The station's systems and experiments consume a large amount of electrical power, almost all of which converts to heat. Little of this heat dissipates through the walls of the station. To keep the internal ambient temperature within comfortable, workable limits, ammonia is continuously pumped through pipes throughout the station to collect heat, then into external radiators to emit infrared radiation, then back into the station. The EATCS consists of an internal, non-toxic, water coolant loop used to cool and dehumidify the atmosphere, which transfers collected heat into an external liquid ammonia loop that can withstand the much lower temperature of space, and is circulated through radiators to remove the heat.
Radio communications provide telemetry and scientific data links between the station and Mission Control Centres. Radio links are also used during rendezvous and docking procedures and for audio and video communication between crew members, flight controllers and family members. As a result, the ISS is equipped with internal and external communication systems used for different purposes. The Russian Orbital Segment communicates directly with the ground via the Lira antenna mounted to Zvezda.
Heat generated by the laptops does not rise but stagnates around the laptop, so additional forced ventilation is required. The operating system used for key station functions is the Debian Linux distribution.
Each permanent crew is given an expedition number. Expeditions run up to six months, from launch until undocking, an 'increment' covers the same time period, but includes cargo ships and all activities. Expeditions 1 to 6 consisted of 3 person crews, Expeditions 7 to 12 were reduced to the safe minimum of two following the destruction of the NASA Shuttle Columbia. From Expedition 13 the crew gradually increased to 6 around Travellers who pay for their own passage into space are termed spaceflight participants by Roscosmos and NASA, and are sometimes referred to as space tourists, a term they generally dislike.
When professional crews change over in numbers not divisible by the three seats in a Soyuz, and a short-stay crewmember is not sent, the spare seat is sold by MirCorp through Space Adventures.
When the space shuttle retired in , and the station's crew size was reduced to 6, space tourism was halted, as the partners relied on Russian transport seats for access to the station.
Soyuz flight schedules increase after , allowing 5 Soyuz flights 15 seats with only two expeditions 12 seats required. Anousheh Ansari became the first Iranian in space and the first self-funded woman to fly to the station. Officials reported that her education and experience make her much more than a tourist, and her performance in training had been "excellent.
She did Russian and European studies involving medicine and microbiology during her day stay. The documentary Space Tourists follows her journey to the station, where she fulfilled "an age-old dream of man: In , spaceflight participant Richard Garriott placed a geocache aboard the ISS during his flight. Spent rocket stages must be dropped into uninhabited areas and this limits the directions rockets can be launched from the spaceport. Orbital boost burns would generally be delayed until after the shuttle's departure.
This allowed shuttle payloads to be lifted with the station's engines during the routine firings, rather than have the shuttle lift itself and the payload together to a higher orbit.
This trade-off allowed heavier loads to be transferred to the station. After the retirement of the NASA shuttle, the nominal orbit of the space station was raised in altitude. Orbital boosting can be performed by the station's two main engines on the Zvezda service module, or Russian or European spacecraft docked to Zvezda 's aft port. The ATV has been designed with the possibility of adding a second docking port to its other end, allowing it to remain at the ISS and still allow other craft to dock and boost the station.
It takes approximately two orbits three hours for the boost to a higher altitude to be completed. The FTCs each contain three identical processing units working in parallel and provide advanced fault-masking by majority voting. Zvezda uses gyroscopes reaction wheels and thrusters to turn itself around.
Gyroscopes do not require propellant, rather they use electricity to 'store' momentum in flywheels by turning in the opposite direction to the station's movement. The USOS has its own computer controlled gyroscopes to handle the extra mass of that section.
When gyroscopes 'saturate' , thrusters are used to cancel out the stored momentum. During Expedition 10 , an incorrect command was sent to the station's computer, using about 14 kilograms of propellant before the fault was noticed and fixed.
The components of the ISS are operated and monitored by their respective space agencies at mission control centres across the globe, including:.
Orbital Replacement Units ORUs are spare parts that can be readily replaced when a unit either passes its design life or fails. Examples of ORUs are pumps, storage tanks, controller boxes, antennas, and battery units.
Some units can be replaced using robotic arms. Both kinds of pallets have electricity as many parts which could be damaged by the cold of space require heating. The larger logistics carriers also have computer local area network connections LAN and telemetry to connect experiments.
Unexpected problems and failures have impacted the station's assembly time-line and work schedules leading to periods of reduced capabilities and, in some cases, could have forced abandonment of the station for safety reasons, had these problems not been resolved. During STS in , following the relocation of the P6 truss and solar arrays, it was noted during the redeployment of the array that it had become torn and was not deploying properly.
The men took extra precautions to reduce the risk of electric shock, as the repairs were carried out with the solar array exposed to sunlight. Excessive vibration and high-current spikes in the array drive motor were noted, resulting in a decision to substantially curtail motion of the starboard SARJ until the cause was understood. Inspections during EVAs on STS and STS showed extensive contamination from metallic shavings and debris in the large drive gear and confirmed damage to the large metallic race ring at the heart of the joint, and so the joint was locked to prevent further damage.
The problem was first noticed in Soyuz imagery in September , but was not thought to be serious. It is also known that a Service Module thruster cover, jettisoned during an EVA in , had struck the S1 radiator, but its effect, if any, has not been determined. On 15 May the damaged radiator panel's ammonia tubing was mechanically shut off from the rest of the cooling system by the computer-controlled closure of a valve.
The same valve was used immediately afterwards to vent the ammonia from the damaged panel, eliminating the possibility of an ammonia leak from the cooling system via the damaged panel.
Early on 1 August , a failure in cooling Loop A starboard side , one of two external cooling loops, left the station with only half of its normal cooling capacity and zero redundancy in some systems. Several subsystems, including two of the four CMGs, were shut down.
A first EVA on 7 August , to replace the failed pump module, was not fully completed because of an ammonia leak in one of four quick-disconnects. A second EVA on 11 August successfully removed the failed pump module. The USOS's cooling system is largely built by the American company Boeing ,  which is also the manufacturer of the failed pump. An air leak from the USOS in ,  the venting of fumes from an Elektron oxygen generator in ,  and the failure of the computers in the ROS in during STS left the station without thruster, Elektron , Vozdukh and other environmental control system operations, the root cause of which was found to be condensation inside the electrical connectors leading to a short-circuit.
In late MBSU-1, while still routing power correctly, ceased responding to commands or sending data confirming its health, and was scheduled to be swapped out at the next available EVA. A spare MBSU was already on board, but 30 August EVA failed to be completed when a bolt being tightened to finish installation of the spare unit jammed before electrical connection was secured.
On 24 December , astronauts made a rare Christmas Eve space walk, installing a new ammonia pump for the station's cooling system. The faulty cooling system had failed earlier in the month, halting many of the station's science experiments.
Astronauts had to brave a "mini blizzard" of ammonia while installing the new pump. A wide variety of crewed and uncrewed spacecraft have supported the station's activities. The Space Shuttle flew there 37 times before retirement. See also the list of professional crew , private travellers , both or just unmanned spaceflights. Soyuz MS 56S aborted shortly after launch on 11 October ; it was carrying two crew members slated to join Expedition 57, who subsequently landed safely.
NASA would have attempted to avoid de-crewing the ISS; commanding the station from the ground is feasible if necessary. All Russian spacecraft and self-propelled modules are able to rendezvous and dock to the space station without human intervention using the Kurs docking system. Radar allows these vehicles to detect and intercept ISS from over kilometres away.
When it catches up it uses laser equipment to optically recognise Zvezda , along with the Kurs system for redundancy. Crew supervise these craft, but do not intervene except to send abort commands in emergencies.
The Japanese H-II Transfer Vehicle parks itself in progressively closer orbits to the station, and then awaits 'approach' commands from the crew, until it is close enough for a robotic arm to grapple and berth the vehicle to the USOS. The American Space Shuttle was manually docked, and on missions with a cargo container , the container would be berthed to the Station with the use of manual robotic arms.
Berthed craft can transfer International Standard Payload Racks. Japanese spacecraft berth for one to two months. Russian and European Supply craft can remain at the ISS for six months,   allowing great flexibility in crew time for loading and unloading of supplies and trash.
NASA Shuttles could remain docked for 11—12 days. The American manual approach to docking allows greater initial flexibility and less complexity. The downside to this mode of operation is that each mission becomes unique and requires specialised training and planning, making the process more labour-intensive and expensive. The Russians pursued an automated methodology that used the crew in override or monitoring roles. Although the initial development costs were high, the system has become very reliable with standardisations that provide significant cost benefits in repetitive routine operations.
Soyuz spacecraft used for crew rotation also serve as lifeboats for emergency evacuation; they are replaced every six months and have been used once to remove excess crew after the Columbia disaster. Prior to a ship's docking to the ISS, navigation and attitude control GNC is handed over to the ground control of the ships' country of origin. GNC is set to allow the station to drift in space, rather than fire its thrusters or turn using gyroscopes.
The solar panels of the station are turned edge-on to the incoming ships, so residue from its thrusters does not damage the cells. When a NASA Space Shuttle docked to the station, other ships were grounded, as the Shuttle's reinforced carbon-carbon wing leading edges, cameras, windows, and instruments were too much at risk from damage or contamination by thruster residue from other ships' movements.
Occasional priority was given to the Soyuz arrivals at the station where the Soyuz carried crew with time-critical cargoes such as biological experiment materials, also causing shuttle delays. Departure of the NASA shuttle was often delayed or prioritised according to weather over its two landing sites. Soyuz launches occur in adverse weather conditions, but the cosmodrome has been shut down on occasions when buried by snow drifts up to 6 metres in depth, hampering ground operations.
A typical day for the crew begins with a wake-up at The crew then eats breakfast and takes part in a daily planning conference with Mission Control before starting work at around The first scheduled exercise of the day follows, after which the crew continues work until Following a one-hour lunch break, the afternoon consists of more exercise and work before the crew carries out its pre-sleep activities beginning at The scheduled sleep period begins at In general, the crew works ten hours per day on a weekday, and five hours on Saturdays, with the rest of the time their own for relaxation or work catch-up.
The windows are covered at night hours to give the impression of darkness because the station experiences 16 sunrises and sunsets per day. The station provides crew quarters for each member of the expedition's crew, with two 'sleep stations' in the Zvezda and four more installed in Harmony. The Russian crew quarters include a small window, but provide less ventilation and sound proofing.
A crew member can sleep in a crew quarter in a tethered sleeping bag, listen to music, use a laptop, and store personal items in a large drawer or in nets attached to the module's walls. The module also provides a reading lamp, a shelf and a desktop. It is possible to sleep floating freely through the station, but this is generally avoided because of the possibility of bumping into sensitive equipment.
Most of the food aboard is vacuum sealed in plastic bags. Cans are rare because they are heavy and expensive to transport. Preserved food is not highly regarded by the crew, and taste is reduced in microgravity. The crew looks forward to the arrival of any ships from Earth, as they bring fresh fruit and vegetables. Care is taken that foods do not create crumbs. Sauces are often used to avoid contaminating station equipment. 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 , and a water dispenser that provides both heated and unheated water. Solid food is eaten with a knife and fork attached to a tray with magnets to prevent them from floating away. Any food that floats away, including crumbs, must be collected to prevent it from clogging the station's air filters and other equipment.
Crews are also provided with rinseless shampoo and edible toothpaste to save water. Astronauts first fasten themselves to the toilet seat, which is equipped with spring-loaded restraining bars to ensure a good seal. Solid waste is collected in individual bags which are stored in an aluminium container. Full containers are transferred to Progress spacecraft for disposal. The diverted urine is collected and transferred to the Water Recovery System, where it is recycled into drinking water.
The authorities found the idea good in theory, but constantly put forward new reasons why the project was unrealizable.
Only when George Pusenkoff wrote to the then Italian ambassador in Russia, Gianfranco Facco Bonetti, the possibility of realizing the idea arose. The connection between science and art, which was also important in Leonardo da Vinci's life, found here an "actualization" in the form of this journey of an image of Mona Lisa into space. For the action, Pusenkoff's painting was removed from the frame so that it could be rolled.
On board the spaceship, the painting was supervised by the Italian astronaut Roberto Vittori. On April 25, , the Soyuz returned to Earth with the painting.
In addition to Pusenkoff's original painting "Single Mona Lisa 1: On this minute piece of metal there is a tiny point. To produce this relief, the tip of a needle is electronically charged and with a computer—driven robot guided to the area on which the image should appear. Finally, the oxygen is withdrawn, and everywhere where the tip of the needle has touched the carrier material, it oxidizes. In this way, a relief is created that is built up of molecules.
Only through the use of a computer that scans signals is it possible to make the work of art visible. The crystal with the image of Mona Lisa painted by Pusenkoff is still on the International Space Station and orbits our planet several times a day.
The ISS is partially protected from the space environment by Earth's magnetic field. Solar flares are still a hazard to the crew, who may receive only a few minutes warning. In , during the initial 'proton storm' of an X-3 class solar flare, the crew of Expedition 10 took shelter in a more heavily shielded part of the ROS designed for this purpose. Subatomic charged particles, primarily protons from cosmic rays and solar wind, are normally absorbed by Earth's atmosphere.
When they interact in sufficient quantity, their effect is visible to the naked eye in a phenomenon called an aurora. Outside Earth's atmosphere, crews are exposed to about 1 millisievert each day, which is about a year of natural exposure on Earth.
This results in a higher risk of cancer for astronauts. Radiation can penetrate living tissue and damage the DNA and chromosomes of lymphocytes. These cells are central to the immune system , and so any damage to them could contribute to the lower immunity experienced by astronauts. Radiation has also been linked to a higher incidence of cataracts in astronauts. Protective shielding and drugs may lower risks to an acceptable level.
Radiation levels on the ISS are about five times greater than those experienced by airline passengers and crew. Earth's electromagnetic field provides almost the same level of protection against solar and other radiation in low Earth orbit as in the stratosphere. For example, on a hour flight an airline passenger would experience 0. Additionally, airline passengers experience this level of radiation for a few hours of flight, while ISS crew are exposed for their whole stay.
There is considerable evidence that psychosocial stressors are among the most important impediments to optimal crew morale and performance. NASA's interest in psychological stress caused by space travel, initially studied when their manned missions began, was rekindled when astronauts joined cosmonauts on the Russian space station Mir. Common sources of stress in early American missions included maintaining high performance under public scrutiny and isolation from peers and family.
A study of the longest spaceflight concluded that the first three weeks are a critical period where attention is adversely affected because of the demand to adjust to the extreme change of environment. The ISS working environment includes further stress caused by living and working in cramped conditions with people from very different cultures who speak a different language.
First-generation space stations had crews who spoke a single language; second- and third-generation stations have crew from many cultures who speak many languages. Astronauts must speak English and Russian , and knowing additional languages is even better.
The ISS is unique because visitors are not classed automatically into 'host' or 'guest' categories as with previous stations and spacecraft, and may not suffer from feelings of isolation in the same way. Crew members with a military pilot background and those with an academic science background or teachers and politicians may have problems understanding each other's jargon and worldview. Due to the lack of gravity, confusion often occurs.
Even though there is no up and down in space, some crew members feel like they are oriented upside down. They may also have difficulty measuring distances. This can cause problems like getting lost inside the space station, pulling switches in the wrong direction or misjudging the speed of an approaching vehicle during docking.
Medical effects of long-term weightlessness include muscle atrophy , deterioration of the skeleton osteopenia , fluid redistribution, a slowing of the cardiovascular system, decreased production of red blood cells, balance disorders, and a weakening of the immune system. Lesser symptoms include loss of body mass, and puffiness of the face.
Sleep is disturbed on the ISS regularly because of mission demands, such as incoming or departing ships. Sound levels in the station are unavoidably high; because the atmosphere is unable to thermosiphon , fans are required at all times to allow processing of the atmosphere which would stagnate in the freefall zero-g environment.
To prevent some of these adverse physiological effects, the station is equipped with two treadmills including the COLBERT , and the aRED advanced Resistive Exercise Device which enables various weightlifting exercises which add muscle but do not compensate for or raise astronauts' reduced bone density,  and a stationary bicycle; each astronaut spends at least two hours per day exercising on the equipment.
Hazardous moulds which can foul air and water filters may develop aboard space stations. They can produce acids which degrade metal, glass, and rubber. They can also be harmful for the crew's health. Microbiological hazards have led to a development of the LOCAD-PTS that can identify common bacteria and moulds faster than standard methods of culturing , which may require a sample to be sent back to Earth.
Reduced humidity, paint with mould-killing chemicals, and antiseptic solutions can be used to prevent contamination in space stations. All materials used in the ISS are tested for resistance against fungi. At the low altitudes at which the ISS orbits, there is a variety of space debris,  consisting of different objects including entire spent rocket stages, defunct satellites, explosion fragments—including materials from anti-satellite weapon tests, paint flakes, slag from solid rocket motors, and coolant released by US-A nuclear-powered satellites.
These objects, in addition to natural micrometeoroids ,  are a significant threat. Large objects could destroy the station, but are less of a threat because their orbits can be predicted.
Despite their small size, some of these objects are a threat because of their kinetic energy and direction in relation to the station. Spacesuits of spacewalking crew could puncture, causing exposure to vacuum. Ballistic panels, also called micrometeorite shielding, are incorporated into the station to protect pressurised sections and critical systems.
According to Forbes magazine Greece's restructuring represents a default. The cash will be handed over after it is clear that private-sector bondholders do indeed join in the haircut, and after Greece gives evidence of the legal framework that it will put in place to implement dozens of "prior actions" - from sacking underproductive tax collectors to passing legislation to liberalise the country's closed professions, tightening rules against bribery and readying at least two large state-controlled companies for sale by June.
It will also have to service its debts from a special, separate escrow account, depositing sums in advance to meet payments that fall due in the following three months. This operation will be supervised by the Troika. Combined this will result in a From Wikipedia, the free encyclopedia. Redirected from Second bailout package Greece. Greek debt crisis Greek economy Tax evasion and corruption in Greece Global financial crisis European debt crisis Financial audits, —10 Anti-austerity movement Election articles Proposed economy referendum, May election Government formation June election January election Greek bailout referendum, September election Greek government debt crisis articles Greek eurozone exit Greek crisis timeline Greek crisis countermeasures v t e.
Retrieved 11 November Was der Bundestag Merkel erlaubt". The analysis was revisited in July , when another commentator saw the situation as yet worse and Germany's pro-austerity stance as hardened, yet more damaging and bringing the risk of a bank-default-trigger, for example, yet closer. Delamaide, Darrell July 24, The Lindner November op-ed also ran in Der Zeit. Retrieved 11 February Retrieved 21 February Retrieved 1 March Archived from the original on Retrieved 9 March How the Greek debt puzzle was solved".
Retrieved 29 February Rat der Europäischen Union. Retrieved 28 October Retrieved 6 March Retrieved 8 March Retrieved from " https: Greek government-debt crisis Eurozone crisis in Greek politics in Greek politics in Greek politics in Greek politics Economic adjustment programmes of the European Union.