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Tuesday, August 23, 2022

Petroleum industry

From Wikipedia, the free encyclopedia
World oil reserves, 2013.

The petroleum industry, also known as the oil industry or the oil patch, includes the global processes of exploration, extraction, refining, transportation (often by oil tankers and pipelines), and marketing of petroleum products. The largest volume products of the industry are fuel oil and gasoline (petrol). Petroleum is also the raw material for many chemical products, including pharmaceuticals, solvents, fertilizers, pesticides, synthetic fragrances, and plastics. The industry is usually divided into three major components: upstream, midstream, and downstream. Upstream regards exploration and extraction of crude oil, midstream encompasses transportation and storage of crude, and downstream concerns refining crude oil into various end products.

Petroleum is vital to many industries, and is necessary for the maintenance of industrial civilization in its current configuration, making it a critical concern for many nations. Oil accounts for a large percentage of the world’s energy consumption, ranging from a low of 32% for Europe and Asia, to a high of 53% for the Middle East.

Other geographic regions' consumption patterns are as follows: South and Central America (44%), Africa (41%), and North America (40%). The world consumes 36 billion barrels (5.8 km³) of oil per year, with developed nations being the largest consumers. The United States consumed 18% of the oil produced in 2015. The production, distribution, refining, and retailing of petroleum taken as a whole represents the world's largest industry in terms of dollar value.

The oil and gas industry spends only 0,4% of its net sales for Research & Development which is in comparison with a range of other industries the lowest share.

Governments such as the United States government provide a heavy public subsidy to petroleum companies, with major tax breaks at various stages of oil exploration and extraction, including the costs of oil field leases and drilling equipment.

In recent years, enhanced oil recovery techniques — most notably multi-stage drilling and hydraulic fracturing ("fracking") — have moved to the forefront of the industry as this new technology plays a crucial and controversial role in new methods of oil extraction.

History

Oil Field in Baku, Azerbaijan, 1926

Prehistory

Natural oil spring in Korňa, Slovakia.

Petroleum is a naturally occurring liquid found in rock formations. It consists of a complex mixture of hydrocarbons of various molecular weights, plus other organic compounds. It is generally accepted that oil is formed mostly from the carbon rich remains of ancient plankton after exposure to heat and pressure in Earth's crust over hundreds of millions of years. Over time, the decayed residue was covered by layers of mud and silt, sinking further down into Earth’s crust and preserved there between hot and pressured layers, gradually transforming into oil reservoirs.

Early history

Petroleum in an unrefined state has been utilized by humans for over 5000 years. Oil in general has been used since early human history to keep fires ablaze and in warfare.

Its importance to the world economy however, evolved slowly, with whale oil being used for lighting in the 19th century and wood and coal used for heating and cooking well into the 20th century. Even though the Industrial Revolution generated an increasing need for energy, this was initially met mainly by coal, and from other sources including whale oil. However, when it was discovered that kerosene could be extracted from crude oil and used as a lighting and heating fuel, the demand for petroleum increased greatly, and by the early twentieth century had become the most valuable commodity traded on world markets.

Modern history

Oil wells in Boryslav
 
Galician oil wells
 
World crude oil production from wells (excludes surface-mined oil, such as from Canadian heavy oil sands), 1930-2012

Imperial Russia produced 3,500 tons of oil in 1825 and doubled its output by mid-century. After oil drilling began in the region of present-day Azerbaijan in 1846, in Baku, the Russian Empire built two large pipelines: the 833 km long pipeline to transport oil from the Caspian to the Black Sea port of Batum (Baku-Batum pipeline), completed in 1906, and the 162 km long pipeline to carry oil from Chechnya to the Caspian. The first drilled oil wells in Baku were built in 1871-1872 by Ivan Mirzoev, an Armenian businessman who is referred to as one of the 'founding fathers' of Baku's oil industry.

At the turn of the 20th century, Imperial Russia's output of oil, almost entirely from the Apsheron Peninsula, accounted for half of the world's production and dominated international markets. Nearly 200 small refineries operated in the suburbs of Baku by 1884. As a side effect of these early developments, the Apsheron Peninsula emerged as the world's "oldest legacy of oil pollution and environmental negligence". In 1846 Baku (Bibi-Heybat settlement) featured the first ever well drilled with percussion tools to a depth of 21 meters for oil exploration. In 1878 Ludvig Nobel and his Branobel company "revolutionized oil transport" by commissioning the first oil tanker and launching it on the Caspian Sea.

Samuel Kier established America's first oil refinery in Pittsburgh on Seventh avenue near Grant Street in 1853. Ignacy Łukasiewicz built one of the first modern oil-refineries near Jasło (then in the Austrian dependent Kingdom of Galicia and Lodomeria in Central European Galicia), present-day Poland, in 1854–56. Galician refineries were initially small, as demand for refined fuel was limited. The refined products were used in artificial asphalt, machine oil and lubricants, in addition to Łukasiewicz's kerosene lamp. As kerosene lamps gained popularity, the refining industry grew in the area.

The first commercial oil-well in Canada became operational in 1858 at Oil Springs, Ontario (then Canada West). Businessman James Miller Williams dug several wells between 1855 and 1858 before discovering a rich reserve of oil four metres below ground. Williams extracted 1.5 million litres of crude oil by 1860, refining much of it into kerosene-lamp oil. Some historians challenge Canada's claim to North America's first oil field, arguing that Pennsylvania's famous Drake Well was the continent's first. But there is evidence to support Williams, not least of which is that the Drake well did not come into production until August 28, 1859. The controversial point might be that Williams found oil above bedrock while Edwin Drake’s well located oil within a bedrock reservoir. The discovery at Oil Springs touched off an oil boom which brought hundreds of speculators and workers to the area. Canada's first gusher (flowing well) erupted on January 16, 1862, when local oil-man John Shaw struck oil at 158 feet (48 m). For a week the oil gushed unchecked at levels reported as high as 3,000 barrels per day.

The first modern oil-drilling in the United States began in West Virginia and Pennsylvania in the 1850s. Edwin Drake's 1859 well near Titusville, Pennsylvania, typically considered the first true modern oil well, touched off a major boom. In the first quarter of the 20th century, the United States overtook Russia as the world's largest oil producer. By the 1920s, oil fields had been established in many countries including Canada, Poland, Sweden, Ukraine, the United States, Peru and Venezuela.

The first successful oil tanker, the Zoroaster, was built in 1878 in Sweden, designed by Ludvig Nobel. It operated from Baku to Astrakhan. A number of new tanker designs developed in the 1880s.

In the early 1930s the Texas Company developed the first mobile steel barges for drilling in the brackish coastal areas of the Gulf of Mexico. In 1937 Pure Oil Company (now part of Chevron Corporation) and its partner Superior Oil Company (now part of ExxonMobil Corporation) used a fixed platform to develop a field in 14 feet (4.3 m) of water, one mile (1.6 km) offshore of Calcasieu Parish, Louisiana. In early 1947 Superior Oil erected a drilling/production oil-platform in 20 ft (6.1 m) of water some 18 miles off Vermilion Parish, Louisiana. Kerr-McGee Oil Industries, as operator for partners Phillips Petroleum (ConocoPhillips) and Stanolind Oil & Gas (BP), completed its historic Ship Shoal Block 32 well in November 1947, months before Superior actually drilled a discovery from their Vermilion platform farther offshore. In any case, that made Kerr-McGee's Gulf of Mexico well, Kermac No. 16, the first oil discovery drilled out of sight of land. Forty-four Gulf of Mexico exploratory wells discovered 11 oil and natural gas fields by the end of 1949.

During World War II (1939–1945) control of oil supply from Romania, Baku, the Middle East and the Dutch East Indies played a huge role in the events of the war and the ultimate victory of the Allies. The Anglo-Soviet invasion of Iran (1941) secured Allied control of oil-production in the Middle East. The expansion of Imperial Japan to the south aimed largely at accessing the oil-fields of the Dutch East Indies. Germany, cut off from sea-borne oil supplies by Allied blockade, failed in Operation Edelweiss to secure the Caucasus oil-fields for the Axis military in 1942, while Romania deprived the Wehrmacht of access to Ploesti oilfields - the largest in Europe - from August 1944. Cutting off the East Indies oil-supply (especially via submarine campaigns) considerably weakened Japan in the latter part of the war. After World War II ended in 1945, the countries of the Middle East took the lead in oil production from the United States. Important developments since World War II include deep-water drilling, the introduction of the drillship, and the growth of a global shipping network for petroleum - relying upon oil tankers and pipelines. In 1949 the first offshore oil-drilling at Oil Rocks (Neft Dashlari) in the Caspian Sea off Azerbaijan eventually resulted in a city built on pylons. In the 1960s and 1970s, multi-governmental organizations of oil–producing nations - OPEC and OAPEC - played a major role in setting petroleum prices and policy. Oil spills and their cleanup have become an issue of increasing political, environmental, and economic importance. New fields of hydrocarbon production developed in places such as Siberia, Sakhalin, Venezuela and North and West Africa.

With the advent of hydraulic fracturing and other horizontal drilling techniques, shale play has seen an enormous uptick in production. Areas of shale such as the Permian Basin and Eagle-Ford have become huge hotbeds of production for the largest oil corporations in the United States.

Structure

NIS refinery in Pančevo, Serbia

The American Petroleum Institute divides the petroleum industry into five sectors:

Upstream

Oil companies used to be classified by sales as "supermajors" (BP, Chevron, ExxonMobil, ConocoPhillips, Shell, Eni and TotalEnergies), "majors", and "independents" or "jobbers". In recent years however, National Oil Companies (NOC, as opposed to IOC, International Oil Companies) have come to control the rights over the largest oil reserves; by this measure the top ten companies all are NOC. The following table shows the ten largest national oil companies ranked by reserves and by production in 2012.

Top 10 largest world oil companies by reserves and production
Rank Company (Reserves) Worldwide Liquids Reserves (109 bbl) Worldwide Natural Gas Reserves (1012 ft3) Total Reserves in Oil Equivalent Barrels (109 bbl)
Company (Production) Output (Millions bbl/day)
1 Saudi Arabia Saudi Aramco 260 254 303
Saudi Arabia Saudi Aramco 12.5
2 Iran NIOC 138 948 300
Iran NIOC 6.4
3 Qatar QatarEnergy 15 905 170
United States ExxonMobil 5.3
4 Iraq INOC 116 120 134
China PetroChina 4.4
5 Venezuela PDVSA 99 171 129
United Kingdom BP 4.1
6 United Arab Emirates ADNOC 92 199 126
Netherlands United Kingdom Royal Dutch Shell 3.9
7 Mexico Pemex 102 56 111
Mexico Pemex 3.6
8 Nigeria NNPC 36 184 68
United States Chevron 3.5
9 Libya NOC 41 50 50
Kuwait Kuwait Petroleum Corporation 3.2
10 Algeria Sonatrach 12 159 39
United Arab Emirates ADNOC 2.9
^1 : Total energy output, including natural gas (converted to bbl of oil) for companies producing both.

Most upstream work in the oil field or on an oil well is contracted out to drilling contractors and oil field service companies.

Aside from the NOCs which dominate the Upstream sector, there are many international companies that have a market share. For example:

Midstream

Midstream operations are sometimes classified within the downstream sector, but these operations compose a separate and discrete sector of the petroleum industry. Midstream operations and processes include the following:

  • Gathering: The gathering process employs narrow, low-pressure pipelines to connect oil- and gas-producing wells to larger, long-haul pipelines or processing facilities.
  • Processing/refining: Processing and refining operations turn crude oil and gas into marketable products. In the case of crude oil, these products include heating oil, gasoline for use in vehicles, jet fuel, and diesel oil. Oil refining processes include distillation, vacuum distillation, catalytic reforming, catalytic cracking, alkylation, isomerization and hydrotreating. Natural gas processing includes compression; glycol dehydration; amine treating; separating the product into pipeline-quality natural gas and a stream of mixed natural gas liquids; and fractionation, which separates the stream of mixed natural gas liquids into its components. The fractionation process yields ethane, propane, butane, isobutane, and natural gasoline.
  • Transportation: Oil and gas are transported to processing facilities, and from there to end users, by pipeline, tanker/barge, truck, and rail. Pipelines are the most economical transportation method and are most suited to movement across longer distances, for example, across continents. Tankers and barges are also employed for long-distance, often international transport. Rail and truck can also be used for longer distances but are most cost-effective for shorter routes.
  • Storage: Midstream service providers provide storage facilities at terminals throughout the oil and gas distribution systems. These facilities are most often located near refining and processing facilities and are connected to pipeline systems to facilitate shipment when product demand must be met. While petroleum products are held in storage tanks, natural gas tends to be stored in underground facilities, such as salt dome caverns and depleted reservoirs.
  • Technological applications: Midstream service providers apply technological solutions to improve efficiency during midstream processes. Technology can be used during compression of fuels to ease flow through pipelines; to better detect leaks in pipelines; and to automate communications for better pipeline and equipment monitoring.

While some upstream companies carry out certain midstream operations, the midstream sector is dominated by a number of companies that specialize in these services. Midstream companies include:

Environmental impact

Water pollution

Some petroleum industry operations have been responsible for water pollution through by-products of refining and oil spills. Though hydraulic fracturing has significantly increased natural gas extraction, there is some belief and evidence to support that consumable water has seen increased in methane contamination due to this gas extraction. Leaks from underground tanks and abandoned refineries may also contaminate groundwater in surrounding areas. Hydrocarbons that comprise refined petroleum are resistant to biodegradation and have been found to remain present in contaminated soils for years. To hasten this process, bioremediation of petroleum hydrocarbon pollutants is often employed by means of aerobic degradation. More recently, other bioremediative methods have been explored such as phytoremediation and thermal remediation.

Air pollution

The industry is the largest industrial source of emissions of volatile organic compounds (VOCs), a group of chemicals that contribute to the formation of ground-level ozone (smog). The combustion of fossil fuels produces greenhouse gases and other air pollutants as by-products. Pollutants include nitrogen oxides, sulphur dioxide, volatile organic compounds and heavy metals.

Researchers have discovered that the petrochemical industry can produce ground-level ozone pollution at higher amounts in winter than in summer.

Climate change

The greenhouse gases due to fossil fuels drive climate change. Already in 1959, at a symposium organised by the American Petroleum Institute for the centennial of the American oil industry, the physicist Edward Teller warned then of the danger of global climate change. Edward Teller explained that carbon dioxide "in the atmosphere causes a greenhouse effect" and that burning more fossil fuels could "melt the icecap and submerge New York".

The Intergovernmental Panel on Climate Change, founded by the United Nations in 1988, concludes that human-sourced greenhouse gases are responsible for most of the observed temperature increase since the middle of the twentieth century.

As a result of climate change concerns, many alternative energy enthusiasts have begun using other methods of energy such as solar and wind, among others. This recent view has some petroleum enthusiasts skeptical about the true future of the industry.

Cumulus cloud

From Wikipedia, the free encyclopedia
 
Cumulus
GoldenMedows.jpg
Small cumulus humilis clouds that can have noticeable vertical development and clearly defined edges.
AbbreviationCu
SymbolCL 1.png
GenusCumulus (heap)
Species
  • Fractus
  • Humilis
  • Mediocris
  • Congestus
Variety
  • Radiatuse
Altitude200–2,000 m
(1,000–7,000 ft)
ClassificationFamily C (Low-level)
AppearanceLow-altitude, fluffy heaps of clouds with cotton-like appearance.
Precipitation cloud?Uncommon Rain, Snow or Snow pellets

Cumulus clouds are clouds which have flat bases and are often described as "puffy", "cotton-like" or "fluffy" in appearance. Their name derives from the Latin cumulo-, meaning heap or pile. Cumulus clouds are low-level clouds, generally less than 2,000 m (6,600 ft) in altitude unless they are the more vertical cumulus congestus form. Cumulus clouds may appear by themselves, in lines, or in clusters.

Cumulus clouds are often precursors of other types of clouds, such as cumulonimbus, when influenced by weather factors such as instability, moisture, and temperature gradient. Normally, cumulus clouds produce little or no precipitation, but they can grow into the precipitation-bearing congests or cumulonimbus clouds. Cumulus clouds can be formed from water vapour, supercooled water droplets, or ice crystals, depending upon the ambient temperature. They come in many distinct subforms and generally cool the earth by reflecting the incoming solar radiation. Cumulus clouds are part of the larger category of free-convective cumuliform clouds, which include cumulonimbus clouds. The latter genus-type is sometimes categorized separately as cumulonimbiform due to its more complex structure that often includes a cirriform or anvil top. There are also cumuliform clouds of limited convection that comprise stratocumulus (low-étage), altocumulus (middle-étage) and cirrocumulus (high-étage). These last three genus-types are sometimes classified separately as stratocumuliform.

Formation

Cumulus clouds form via atmospheric convection as air warmed by the surface begins to rise. As the air rises, the temperature drops (following the lapse rate), causing the relative humidity (RH) to rise. If convection reaches a certain level the RH reaches one hundred percent, and the "wet-adiabatic" phase begins. At this point a positive feedback ensues: since the RH is above 100%, water vapor condenses, releasing latent heat, warming the air and spurring further convection.

In this phase, water vapor condenses on various nuclei present in the air, forming the cumulus cloud. This creates the characteristic flat-bottomed puffy shape associated with cumulus clouds. The height of the cloud (from its bottom to its top) depends on the temperature profile of the atmosphere and of the presence of any inversions. During the convection, surrounding air is entrained (mixed) with the thermal and the total mass of the ascending air increases. Rain forms in a cumulus cloud via a process involving two non-discrete stages. The first stage occurs after the droplets coalesce onto the various nuclei. Langmuir writes that surface tension in the water droplets provides a slightly higher pressure on the droplet, raising the vapor pressure by a small amount. The increased pressure results in those droplets evaporating and the resulting water vapor condensing on the larger droplets. Due to the extremely small size of the evaporating water droplets, this process becomes largely meaningless after the larger droplets have grown to around 20 to 30 micrometres, and the second stage takes over. In the accretion phase, the raindrop begins to fall, and other droplets collide and combine with it to increase the size of the raindrop. Langmuir was able to develop a formula which predicted that the droplet radius would grow unboundedly within a discrete time period.

Description

Cumulus clouds seen from above

The liquid water density within a cumulus cloud has been found to change with height above the cloud base rather than being approximately constant throughout the cloud. In one particular study, the concentration was found to be zero at cloud base. As altitude increased, the concentration rapidly increased to the maximum concentration near the middle of the cloud. The maximum concentration was found to be anything up to 1.25 grams of water per kilogram of air. The concentration slowly dropped off as altitude increased to the height of the top of the cloud, where it immediately dropped to zero again.

Lines of Cumulus clouds over Brittany

Cumulus clouds can form in lines stretching over 480 kilometres (300 mi) long called cloud streets. These cloud streets cover vast areas and may be broken or continuous. They form when wind shear causes horizontal circulation in the atmosphere, producing the long, tubular cloud streets. They generally form during high-pressure systems, such as after a cold front.

The height at which the cloud forms depends on the amount of moisture in the thermal that forms the cloud. Humid air will generally result in a lower cloud base. In temperate areas, the base of the cumulus clouds is usually below 550 metres (1,800 ft) above ground level, but it can range up to 2,400 metres (7,900 ft) in altitude. In arid and mountainous areas, the cloud base can be in excess of 6,100 metres (20,000 ft).

Some cumulus mediocris clouds

Cumulus clouds can be composed of ice crystals, water droplets, supercooled water droplets, or a mixture of them. The water droplets form when water vapor condenses on the nuclei, and they may then coalesce into larger and larger droplets.

One study found that in temperate regions, the cloud bases studied ranged from 500 to 1,500 metres (1,600 to 4,900 ft) above ground level. These clouds were normally above 25 °C (77 °F), and the concentration of droplets ranged from 23 to 1,300 droplets per cubic centimetre (380 to 21,300 per cubic inch). This data was taken from growing isolated cumulus clouds that were not precipitating. The droplets were very small, ranging down to around 5 micrometres in diameter. Although smaller droplets may have been present, the measurements were not sensitive enough to detect them. The smallest droplets were found in the lower portions of the clouds, with the percentage of large droplets (around 20 to 30 micrometres) rising dramatically in the upper regions of the cloud. The droplet size distribution was slightly bimodal in nature, with peaks at the small and large droplet sizes and a slight trough in the intermediate size range. The skew was roughly neutral. Furthermore, large droplet size is roughly inversely proportional to the droplet concentration per unit volume of air.

In places, cumulus clouds can have "holes" where there are no water droplets. These can occur when winds tear the cloud and incorporate the environmental air or when strong downdrafts evaporate the water.

Subforms

Cumulus clouds come in four distinct species, cumulus humilis, mediocris, congestus, and fractus. These species may be arranged into the variety, cumulus radiatus; and may be accompanied by up to seven supplementary features, cumulus pileus, velum, virga, praecipitatio, arcus, pannus, and tuba.

The species Cumulus fractus is ragged in appearance and can form in clear air as a precursor to cumulus humilis and larger cumulus species-types; or it can form in precipitation as the supplementary feature pannus (also called scud) which can also include stratus fractus of bad weather. Cumulus humilis clouds look like puffy, flattened shapes. Cumulus mediocris clouds look similar, except that they have some vertical development. Cumulus congestus clouds have a cauliflower-like structure and tower high into the atmosphere, hence their alternate name "towering cumulus". The variety Cumulus radiatus forms in radial bands called cloud streets and can comprise any of the four species of cumulus.

Cumulus supplementary features are most commonly seen with the species congestus. Cumulus virga clouds are cumulus clouds producing virga (precipitation that evaporates while aloft), and cumulus praecipitatio produce precipitation that reaches the Earth's surface. Cumulus pannus comprise shredded clouds that normally appear beneath the parent cumulus cloud during precipitation. Cumulus arcus clouds have a gust front, and cumulus tuba clouds have funnel clouds or tornadoes. Cumulus pileus clouds refer to cumulus clouds that have grown so rapidly as to force the formation of pileus over the top of the cloud. Cumulus velum clouds have an ice crystal veil over the growing top of the cloud. There are also cumulus cataractagenitus. These are formed by waterfalls.

Forecast

Cumulus humilis clouds usually indicate fair weather. Cumulus mediocris clouds are similar, except that they have some vertical development, which implies that they can grow into cumulus congestus or even cumulonimbus clouds, which can produce heavy rain, lightning, severe winds, hail, and even tornadoes. Cumulus congestus clouds, which appear as towers, will often grow into cumulonimbus storm clouds. They can produce precipitation. Glider pilots often pay close attention to cumulus clouds, as they can be indicators of rising air drafts or thermals underneath that can suck the plane high into the sky—a phenomenon known as cloud suck.

Effects on climate

Cumulus congestus clouds compared against a cumulonimbus cloud in the background

Due to reflectivity, clouds cool the earth by around 12 °C (22 °F), an effect largely caused by stratocumulus clouds. However, at the same time, they heat the earth by around 7 °C (13 °F) by reflecting emitted radiation, an effect largely caused by cirrus clouds. This averages out to a net loss of 5 °C (9.0 °F). Cumulus clouds, on the other hand, have a variable effect on heating the earth's surface. The more vertical cumulus congestus species and cumulonimbus genus of clouds grow high into the atmosphere, carrying moisture with them, which can lead to the formation of cirrus clouds. The researchers speculated that this might even produce a positive feedback, where the increasing upper atmospheric moisture further warms the earth, resulting in an increasing number of cumulus congestus clouds carrying more moisture into the upper atmosphere.

Relation to other clouds

Cumulus clouds are a genus of free-convective low-level cloud along with the related limited-convective cloud stratocumulus. These clouds form from ground level to 2,000 metres (6,600 ft) at all latitudes. Stratus clouds are also low-level. In the middle level are the alto- clouds, which consist of the limited-convective stratocumuliform cloud altocumulus and the stratiform cloud altostratus. Mid-level clouds form from 2,000 metres (6,600 ft) to 7,000 metres (23,000 ft) in polar areas, 7,000 metres (23,000 ft) in temperate areas, and 7,600 metres (24,900 ft) in tropical areas. The high-level cloud, cirrocumulus, is a stratocumuliform cloud of limited convection. The other clouds in this level are cirrus and cirrostratus. High clouds form 3,000 to 7,600 metres (9,800 to 24,900 ft) in high latitudes, 5,000 to 12,000 metres (16,000 to 39,000 ft) in temperate latitudes, and 6,100 to 18,000 metres (20,000 to 59,100 ft) in low, tropical latitudes. Cumulonimbus clouds, like cumulus congestus, extend vertically rather than remaining confined to one level.

Cirrocumulus clouds

A large field of cirrocumulus clouds in a blue sky, beginning to merge near the upper left.
A large field of cirrocumulus clouds
 

Cirrocumulus clouds form in patches and cannot cast shadows. They commonly appear in regular, rippling patterns or in rows of clouds with clear areas between. Cirrocumulus are, like other members of the cumuliform and stratocumuliform categories, formed via convective processes. Significant growth of these patches indicates high-altitude instability and can signal the approach of poorer weather. The ice crystals in the bottoms of cirrocumulus clouds tend to be in the form of hexagonal cylinders. They are not solid, but instead tend to have stepped funnels coming in from the ends. Towards the top of the cloud, these crystals have a tendency to clump together. These clouds do not last long, and they tend to change into cirrus because as the water vapor continues to deposit on the ice crystals, they eventually begin to fall, destroying the upward convection. The cloud then dissipates into cirrus. Cirrocumulus clouds come in four species which are common to all three genus-types that have limited-convective or stratocumuliform characteristics: stratiformis, lenticularis, castellanus, and floccus. They are iridescent when the constituent supercooled water droplets are all about the same size.

Altocumulus clouds

Altocumulus clouds
 

Altocumulus clouds are a mid-level cloud that forms from 2,000 metres (6,600 ft) high to 4,000 metres (13,000 ft) in polar areas, 7,000 metres (23,000 ft) in temperate areas, and 7,600 metres (24,900 ft) in tropical areas. They can have precipitation and are commonly composed of a mixture of ice crystals, supercooled water droplets, and water droplets in temperate latitudes. However, the liquid water concentration was almost always significantly greater than the concentration of ice crystals, and the maximum concentration of liquid water tended to be at the top of the cloud while the ice concentrated itself at the bottom. The ice crystals in the base of the altocumulus clouds and in the virga were found to be dendrites or conglomerations of dendrites while needles and plates resided more towards the top. Altocumulus clouds can form via convection or via the forced uplift caused by a warm front.

Stratocumulus clouds

Stratocumulus clouds
 

A stratocumulus cloud is another type of stratocumuliform cloud. Like cumulus clouds, they form at low levels and via convection. However, unlike cumulus clouds, their growth is almost completely retarded by a strong inversion. As a result, they flatten out like stratus clouds, giving them a layered appearance. These clouds are extremely common, covering on average around twenty-three percent of the earth's oceans and twelve percent of the earth's continents. They are less common in tropical areas and commonly form after cold fronts. Additionally, stratocumulus clouds reflect a large amount of the incoming sunlight, producing a net cooling effect. Stratocumulus clouds can produce drizzle, which stabilizes the cloud by warming it and reducing turbulent mixing.

Cumulonimbus clouds

Cumulonimbus clouds are the final form of growing cumulus clouds. They form when cumulus congestus clouds develop a strong updraft that propels their tops higher and higher into the atmosphere until they reach the tropopause at 18,000 metres (59,000 ft) in altitude. Cumulonimbus clouds, commonly called thunderheads, can produce high winds, torrential rain, lightning, gust fronts, waterspouts, funnel clouds, and tornadoes. They commonly have anvil clouds.

Horseshoe clouds

A short-lived horseshoe cloud may occur when a horseshoe vortex deforms a cumulus cloud.

Extraterrestrial

Some cumuliform and stratocumuliform clouds have been discovered on most other planets in the solar system. On Mars, the Viking Orbiter detected cirrocumulus and stratocumulus clouds forming via convection primarily near the polar icecaps. The Galileo space probe detected massive cumulonimbus clouds near the Great Red Spot on Jupiter. Cumuliform clouds have also been detected on Saturn. In 2008, the Cassini spacecraft determined that cumulus clouds near Saturn's south pole were part of a cyclone over 4,000 kilometres (2,500 mi) in diameter. The Keck Observatory detected whitish cumulus clouds on Uranus. Like Uranus, Neptune has methane cumulus clouds. Venus, however, does not appear to have cumulus clouds.

Astronaut training

From Wikipedia, the free encyclopedia
 
A test subject being suited up for studies on the Reduced Gravity Walking Simulator. This position meant that a person's legs experienced only one sixth of their weight, which was the equivalent of being on the lunar surface. The purpose of this simulator was to study the subject while walking, jumping or running. (1963)

Astronaut training describes the complex process of preparing astronauts in regions around the world for their space missions before, during and after the flight, which includes medical tests, physical training, extra-vehicular activity (EVA) training, procedure training, rehabilitation process, as well as training on experiments they will accomplish during their stay in space.

Virtual and physical training facilities have been integrated to familiarize astronauts with the conditions they will encounter during all phases of flight and prepare astronauts for a microgravity environment. Special considerations must be made during training to ensure a safe and successful mission, which is why the Apollo astronauts received training for geology field work on the Lunar surface and why research is being conducted on best practices for future extended missions, such as the trip to Mars.

Purpose of training

Training flow

The selection and training of astronauts are integrated processes to ensure the crew members are qualified for space missions. The training is categorized into five objectives to train the astronauts on the general and specific aspects: basic training, advanced training, mission-specific training, onboard training, and proficiency maintenance training. The trainees must learn medicine, language, robotics and piloting, space system engineering, the organization of space systems, and the acronyms in aerospace engineering during the basic training. While 60% to 80% of the astronauts will experience space motion sickness, including pallor, cold sweating, vomiting, and anorexia, the astronaut candidates are expected to overcome the sickness. During the advanced training and the mission specific training, astronauts will learn about the operation of specific systems and skills required associated with their assigned positions in a space mission. The mission specific training typically requires 18 months to complete for Space Shuttle and International Space Station crews. It is important to ensure the astronauts’ well-being, physical and mental health prior, during, and after the mission period. Proficiency maintenance aims to help the crew members to maintain a minimum level of performance, including topics such as extravehicular activity, robotics, language, diving, and flight training.

Launch and landing

The effects of launching and landing has various effects on astronauts, with the most significant effects that occur being space motion sickness, orthostatic intolerance, and cardiovascular events.

Space motion sickness is an event that can occur within minutes of being in changing gravity environments (i.e. from 1g on Earth prior to launch to more than 1g during launch, and then from microgravity in space to hypergravity during re-entry and again to 1g after landing). The symptoms range from drowsiness and headaches, to nausea and vomiting. There are three general categories of space motion sickness:

  • Mild: One to several transient symptoms, no operational impact
  • Moderate: Several symptoms of persistent nature, minimal operational impact
  • Severe: Several symptoms of persistent nature, significant impact on performance

About three-fourths of astronauts experience space motion sickness, with effects rarely exceeding two days. There is a risk for post-flight motion sickness, however this is only significant following long-duration space missions.

Post-flight, following exposure to microgravity, the vestibular system, located in the inner ear is disrupted because of the microgravity-induced unresponsiveness of the otoliths which are small calcareous concretions that sense body postures and are responsible for ensuring proper balance. In most cases, this leads to some postflight postural illusions.

Cardiovascular events represent important factors during the three phases of a space mission. They can be divided in:

  • Pre-existing cardiovascular diseases: these are typically selected-out during astronaut selection, but if they are present in an astronaut they can worsen over the course of the spaceflight.
  • Cardiovascular events and changes occurring during spaceflight: these are due to body fluids shift and redistribution, heart rhythm disturbances and decrease in maximal exercise capacity in the micro gravity environment. These effects can potentially lead the crew to be severely incapacitated upon return to a gravitational environment and thus unable to egress a spacecraft without assistance.
  • Orthostatic intolerance leading to syncope during post-flight stand test.

On-orbit operations

Astronauts are trained in preparation for the conditions of launch as well as the harsh environment of space. This training aims to prepare the crew for events falling under two broad categories: events relating to operation of the spacecraft (internal events), and events relating to the space environment (external events)

An internal view of ESA's Columbus module training mockup, located at the European Astronaut Centre in Cologne, Germany. Astronauts must familiarize themselves with all the spacecraft components during their training.

During training, astronauts are familiarized with the engineering systems of the spacecraft including spacecraft propulsion, spacecraft thermal control, and life support systems. In addition to this, astronauts receive training in orbital mechanics, scientific experimentation, earth observation, and astronomy. This training is particularly important for missions when an astronaut will encounter multiple systems (for example on the International Space Station (ISS)). Training is performed in order to prepare astronauts for events that may pose a hazard to their health, the health of the crew, or the successful completion of the mission. These types of events may be: failure of a critical life support system, capsule depressurization, fire, and other life-threatening events. In addition to the need to train for hazardous events, astronauts will also need to train to ensure the successful completion of their mission. This could be in the form of training for EVA, scientific experimentation, or spacecraft piloting.

External events

External events refers more broadly to the ability to live and work in the extreme environment of space. This includes adaptation to microgravity (or weightlessness), isolation, confinement, and radiation. The difficulty associated with living and working in microgravity include spatial disorientation, motion sickness, and vertigo. During long-duration missions, astronauts will often experience isolation and confinement. This has been known to limit performance of astronaut crews and hence training aims to prepare astronauts for such challenges. The long-term effects of radiation on crews is still largely unknown. However, it is theorized that astronauts on a trip to Mars will likely receive more than 1000x the radiation dosage of a typical person on earth. As such, present and future training must incorporate systems and processes for protecting astronauts against radiation.

Science experiments

Scientific experimentation has historically been an important element of human spaceflight, and is the primary focus of the International Space Station. Training on how to successfully carry out these experiments is an important part of astronaut training, as it maximizes the scientific return of the mission. Once on-orbit, communication between astronauts and scientists on the ground can be limited, and time is strictly apportioned between different mission activities. It is vital that astronauts are familiar with their assigned experiments in order to complete them in a timely manner, with as little intervention from the ground as possible.

For missions to the ISS, each astronaut is required to become proficient at one hundred or more experiments. During training, the scientists responsible for the experiments do not have direct contact with the astronauts who will be carrying them out. Instead, scientists instruct trainers who in turn prepare the astronauts for carrying out the experiment. Much of this training is done at the European Astronaut Center.

For human experiments, the scientists describe their experiments to the astronauts who then choose whether to participate on board the ISS. For these experiments, the astronauts will be tested before, during, and after the mission to establish a baseline and determine when the astronaut returned to the baseline.

A researcher using VR headset to investigate ideas for controlling rovers on a planet.

Purpose of virtual reality training

Virtual reality training for astronauts intends to give the astronauts candidates an immersive training experience. Virtual reality has been explored as a technology to artificially expose astronauts to space conditions and procedures prior to going into space. Using virtual reality, astronauts can be trained and evaluated on performing an EVA (extravehicular activity) with all the necessary equipment and environmental features simulated. This modern technology also allows the scenario to be changed on the go, such as to test emergency protocols. The VR training systems can reduce the effects of the space motion sickness through a process of habituation. Preflight VR training can be a countermeasure for space motion sickness and disorientation due to the weightlessness of the microgravity environment. When the goal is to act as a practice tool, virtual reality is commonly explored in conjunction with robotics and additional hardware to increase the effect of immersion or the engagement of the trainee.

Training by region

United States

At NASA, following the selection phase, the so-called "AsCans" (Astronaut candidates) have to undergo up to two years of training/indoctrination period to become fully qualified astronauts. Initially, all AsCans must go through basic training to learn both technical and soft skills. There are 16 different technical courses in:

Astronauts train in the Neutral Buoyancy Facility at the Johnson Space Center in Houston, Texas
 
The Crew of STS-135 practices rendezvous and docking with the ISS in the Systems Engineering Simulator at the Johnson Space Center on June 28, 2011 in Houston, Texas.

AsCans initially go through Basic Training, where they are trained on Soyuz, and ISS systems, flight safety and operations, as well as land or water survival. Pilot AsCans will receive training on NASA's T-38 Trainer Jet. Furthermore, because modern space exploration is done by a consortium of different countries and is a very publicly visible area, astronauts received professional and cultural training, as well as language courses (specifically in Russian).

Following completion of Basic Training candidates proceed to NASA's Advanced Training. AsCans are trained on life-sized models to get a feel of what they will be doing in space. This was done both through the use of the Shuttle Training Aircraft while it was still operational and is done through simulation mock-ups. The shuttle training aircraft was exclusively used by the commander and pilot astronauts for landing practices until the retirement of the Shuttle, while advanced simulation system facilities are used by all the candidates to learn how to work and successfully fulfill their tasks in the space environment. Simulators and EVA training facilities help candidates to best prepare their different mission operations. In particular, vacuum chambers, parabolic flights, and neutral buoyancy facilities (NBF) allow candidates to get acclimated to the micro gravity environment, particularly for EVA. Virtual reality is also becoming increasingly used as a tool to immerse AsCans into the space environment.

The final phase is the Intensive Training. It starts at about three months prior to launch, preparing candidates for their assigned mission. Flight-specific integrated simulations are designed to provide a dynamic testing ground for mission rules and flight procedures. The final Intensive Training joint crew/flight controller training is carried out in parallel with mission planning. This phase is where candidates will undergo mission specific operational training, as well as experience with their assigned experiments. Crew medical officer training is also included to effectively intervene with proactive and reactive actions in case of medical issues.

Notable training facilities

It can take up to two years for an AsCan to become formally qualified as an astronaut. Usually, the training process are completed with various training facilities available in NASA: Space training facilities try to replicate or simulate the experience of spaceflight in a spacecraft as closely and realistically as possible. This includes full-size cockpit replicas mounted on hydraulic rams and controlled by state of the art computer technology; elaborate watertanks for simulation of weightlessness; and devices used by scientists to study the physics and environment of outer space.

  • Space Vehicle Mock-up Facility (SVMF): located in the Johnson Space Center in Houston, TX. The SVMF consists of life-size models of vehicles of the ISS, the Orion, and different other commercial programs. The purpose of SVMF is to provide a unique simulated experience for astronauts to get familiar with their tasks in space vehicles. Potential training projects include preparation of emergency, on-orbit intra-vehicular maintenance, and airlock operations. The facility also provides experiences for astronauts in real-time communications with the ground team for mission support.
  • KC-135 Stratotanker: the KC-135 is an air-refueling plane designed by Boeing. Known as the “Weightless Wonder” or the “Vomit Comet”, this plane is the most famous of its kind, which has served to simulate reduced or microgravity environments for NASA astronauts since 1994. The “roller coaster” maneuvers that the plane is capable of doing provide people as well as equipment onboard about 20–25 seconds of weightlessness.
  • The Precision Air-Bearing Floor (PABF): located in the Johnson Space Center in Houston, TX. Because of the microgravity environment in space, the resulting lack of friction posts difficulties for astronauts to move and stop large objects. The PABF is a “flat floor” that uses compressed air to suspend typical hardwares or mock-ups that astronauts may encounter in space above the ground. It is used to simulate low-friction environments for astronauts to learn to move large objects.
  • The Neutral Buoyancy Lab: (NBL): located in the Johnson Space Center in Houston, TX. Through a combination of weighting and floating effects, the NBL creates a balance between the tendencies to sink and to float, and therefore simulating the experience of weightlessness. In the NBL, several full-size models of the space vehicles are present in a large “water tank”. Unlike the SVMF, the NBL helps astronauts train on projects such as maintenance, but outside of the space vehicle.

Europe

Astronaut training in Europe is carried out by the European Astronaut Centre (EAC), headquartered in Cologne, Germany. European training has three phases: Basic training, Advanced training, and Increment Specific Training.

Soyuz capsule simulator located at the EAC in Cologne, Germany. ESA astronauts will simulate operations in the capsule at the EAC.

For all ESA selected astronauts, Basic Training begins at the EAC headquarters. This section of the training cycle has four separate training blocks that last 16 months. Astronauts will receive an orientation on the major spacefaring nations, their space agencies, and all major crewed and uncrewed space programs. Training in this phase also looks into applicable laws and policies of the space sector. Technical (including engineering, astrodynamics, propulsion, orbital mechanics, etc.) and scientific (including human physiology, biology, earth observation, and astronomy) basics are introduced, to ensure that all new astronauts have the required base level of knowledge. Training is done on ISS operations and facilities, including an introduction to all major operating systems on board the ISS that are required for its functionality as a crewed space research laboratory. This phase also covers in-depth systems operations for all spacecraft that service the ISS (e.g. Soyuz, Progress, Automatic Transfer Vehicle (ATV), and the H-II Transfer Vehicle (HTV)), as well as ground control and launch facility training. This training phase also focuses on skills such as robotic operations, rendezvous and docking, Russian language courses, human behavior and performance, and finally a PADI open water scuba diving course. This scuba course provides basic EVA training at ESA's NBF before moving onto the larger NASA training facility at the Lyndon B. Johnson Space Center.

Advanced Training includes a much more in-depth look into the ISS, including learning how to service and operate all systems. Enhanced science training is also implemented at this time to ensure all astronauts can perform science experiments on board the ISS. This phase takes around one year to complete and training is completed across the ISS partner network, no longer only at the EAC. It is only upon completion of this phase that astronauts are assignment to a spaceflight.

Increment-Specific Training starts only after an astronaut has been assigned to a flight. This phase lasts 18 months and prepares them for their role on their assigned mission. During this phase crew members as well as backup crews will train together. The crew tasks on the ISS are individually tailored, with consideration to the astronaut's particular experience and professional background. There are three different user levels for all on-board equipment (i.e. user level, operator level, and specialist level). A crew member can be a specialist on systems while also only being an operator or user on others, hence why the training program is individually tailored. Increment Specific Training also includes training to deal with off-nominal situations. Astronauts will also learn how to run the experiments that are specifically scheduled for their assigned missions.

Russia

The grounds of the Gagarin Cosmonauts Training Center

Training for cosmonauts falls into three phases: General Space Training, Group Training, and Crew Training. General Space Training lasts about two years and consists of classes, survival training, and a final exam which determines whether a cosmonaut will be a test or research cosmonaut. The next year is devoted to Group Training where cosmonauts specialize in the Soyuz or ISS as well as professional skills. The final phases, the Crew Training phase, lasts a year and a half and is dedicated to detailed vehicle operations procedures, ISS training, and the English language.

Training primarily takes place at the Yuri Gagarin Cosmonaut Training Center. The center facilities have full size mockups of all major Soviet and Russian spacecraft including the ISS. As with the ISS astronauts, cosmonauts train in the US, Germany, Japan, and Canada for specific training in the various ISS modules.

Japan

The Japanese human spaceflight program has historically focused on training astronauts for Space Shuttle missions. As such, training previously took place at NASA's Lyndon B. Johnson Space Center, and followed that of NASA astronauts and other international participants in the Space Shuttle program.

H-II rocket outside the Tsukuba Space Center where training of JAXA astronauts takes place

Since the development of domestic training facilities at the Tsukuba Space Center, training has increasingly taken place in Japan. With Japan's participation in the ISS, the training of Japanese astronauts follows a similar structure to that of other ISS partners. Astronauts carry out 1.5 years of Basic Training mainly at Tsukuba, followed by 1.5–2 years of Advanced Training at Tsukuba and ISS partner sites. Training for any international ISS astronauts involving the Kibo module will also be carried out at Tsukuba Space Center.

Advanced Training is followed by Increment-Specific Training, which, along with any Kibo training, will be carried out at Tsukuba. EVA training for Kibo takes place in the Weightless Environment Test System (WETS). WETS is a Neutral Buoyancy Facility featuring a full-scale mock-up of the Kibo module on the ISS. The Tsukuba Space Center also includes medical facilities for assessing suitability of candidates, an isolation chamber for simulating some of the mental and emotional stressors of long duration spaceflight, and a hypobaric chamber for training in hull breach or Life Support System failure scenarios resulting in a reduction or loss of air pressure.

China

Although official detail of the selection process for the Shenzhou program is not available, what is known is that candidates are chosen by the Chinese National Space Administration from the Chinese air force and must be between 25 and 30 years of age, with a minimum of 800 hours flying time, and a degree-level education. Candidates must be between 160 cm and 172 cm in height, and between 50 kg and 70 kg in weight.

For China's Shenzhou astronauts, training begins with a year-long program of education in the basics of spaceflight. During this period, candidates are also introduced to human physiology and psychology. The second phase of training, lasting nearly 3 years involves extensive training in piloting the Shenzhou vehicle in nominal and emergency modes. The third and final stage of training is mission specific training, and lasts approximately 10 months. During this phase of training, astronauts are trained in the high fidelity Shenzhou trainer, as well as the Neutral Buoyancy Facility located at the Astronaut Center of China (ACC), in Beijing. As well as time spent in the Neutral Buoyancy Facility (NBF), training for EVA takes place in a high vacuum, low temperature chamber that simulates the environmental conditions of space. At all stages of training, astronauts undergo physical conditioning, including time in a human centrifuge located at the ACC, and a program of micro gravity flights, carried out in Russia.

India

The Indian human space flight program still awaits a formal go ahead. Once cleared the mission is expected to take two Indians in a Soyuz-type orbital vehicle into low Earth orbit. The training for these astronauts should be based on the lessons learned from training India's only Cosmonaut Wing Commander Rakesh Sharma (See Salyut-7 1984) and through India's international co-operation with NASA and Roscosmos. This would allow India to gain insights from their rich experiences in human spaceflight. There also lies a possibility that India may go proceed through its human spaceflight program individually, necessitating the Indian Space Research Organisation (ISRO) to develop its own training program. For astronaut training, India is deciding a place which is at a distance of 8 to 10 km from Kempegowda international airport. This land is under the ownership of ISRO. Astronaut training and biomedical engineering centers will be built on it. Though India's first man mission training will take place in USA or in Russia, this place can be used for future training. Moreover, center will have chambers for radiation regulation, thermal cycling and centrifugal for the acceleration training.

Future training

Suborbital astronaut training

Ecuadorian Civilian Space Agency (EXA)

While the first generation of non-government spaceflight astronauts will likely perform suborbital trajectories, currently companies like Virgin Galactic and Xcor Aerospace are developing proprietary suborbital astronaut training programs. However, the first official Suborbital Astronaut Training program was a joint effort between two government agencies. The Ecuadorian Air Force and the Gagarin Cosmonaut Training Center developed the ASA/T (Advanced Suborbital Astronaut Training) program which lasted up to 16 months between 2005 to 2007 and focused on command and research duties during short missions with suborbital trajectories up to 180 kilometers. This program had one Ecuadorian citizen graduate in 2007, the Ecuadorian Space Agency made a call for a new class of ASA/T training candidates, accordingly to the EXA, they will focus on renting commercial suborbital vehicles in order to perform crewed space research

Commercial astronauts

Human centrifuge at DLR in Cologne, Germany used for human physiological tests. The high accelerations experienced during suborbital flights may necessitate testing or even training on human centrifuges to determine if participants are fit for space flight

Looking ahead, the emergence of commercial space tourism will necessitate new standards for flight participants that currently do not exist. These standards will be to ensure that medical screenings are done properly in order to ensure safe and successful flights. This process will differ from that for space agency astronauts because the goal is not to fly the best individual, but to ensure a safe flight for the passengers. The main considerations for this type of travel will be:

  • What type and extent of training is sufficient?
  • Who will qualify space tourists as fit for travel?
  • How will new regulations comply with existing medical boards?
  • What selection-out criteria need to be employed to reduce dangers to space tourists?

Medical regulations for commercial space flight might mitigate commercial space company risk by selecting only those capable of passing standard medical criteria, as opposed to allowing anyone who can purchase a ticket to fly. The first generation of commercial space flight will likely be suborbital trajectories which invoke significant acceleration changes, causing cardiovascular and pulmonary issues. Because of this any future medical criteria for commercial spaceflight participants needs to focus specifically on the detrimental effects of rapidly changing gravitational levels, and which individuals will be capable of tolerating this.

A fundamentals of scientist-astronaut formative program along with additional Bioastronautics, Extravehicular activity, Space Flight Operations, Flight Test Engineering and Upper-Atmospheric Research courses have been conducted by Project PoSSUM scientist-astronaut candidates since 2015.  As of January 2021, the program has attracted members from 46 different countries and published research on mesospheric dynamics, human performance in space suits, microgravity research in various fields, and post-landing environments. The programs are run by the International Institute of Astronautical Sciences that has also partnered with Embry-Riddle Aeronautical University, Final Frontier Design Spacesuits, Survival Systems USA, National Research Council of Canada, Canadian Space Agency and the National Association of Underwater Instructors.

Current research on fitness training and strategies for commercial astronauts conducted by Astrowright Spaceflight Consulting, the first commercial firm to offer dedicated fitness training for space tourists, suggests that conventional fitness training is inadequate to support safe movement in microgravity, and that training utilizing reduced points of stability should be emphasized.

Long-duration missions to the Moon or Mars

Astronaut during virtual reality training

Astronauts for long term missions–such as those to the Moon or Mars–need to carry out multiple tasks and duties, because on such missions the astronauts will need to function largely autonomously, and will need to be proficient in many different areas. For these types of missions, the training to prepare astronauts will likely include training as doctors, scientists, engineers, technicians, pilots, and geologists. In addition there will be a focus on the psychological aspects of long-duration missions where crew is largely isolated.

Currently a six-month mission to the ISS requires up to five years of astronaut training. This level of training is to be expected and likely to be expanded upon for future space exploration missions. It may also include in-flight training aspects. It may be possible that the ISS will be used as a long-duration astronaut training facility in the future.

A powerful tool for astronaut training will be the continuing use of analog environments, including NASA Extreme Environment Mission Operations (NOAA NEEMO), NASA's Desert Research and Technology Studies (Desert RATS), Envihab (planned), Flight Analog Research Unit, Haughton-Mars Project (HMP), or even the ISS (in-flight). In fact, at NEEMO a total of 15 mission astronauts (known as aquanauts) have been trained for future missions to asteroids. The use of virtual reality will also continue to be used as a means of training astronauts in a cost-effective manner, particularly for operations such as extra-vehicular activity (EVA).

Robonaut2 onboard ISS

These missions are not completely independent without the presence of robots. This opens up a new avenue towards Human-Robot Interaction which has to be thoroughly understood and practised to develop a harmonious relationship between astronauts and robots. These robots would aid the astronauts from being their personal assistants to next generation of extreme environment explorers. Currently there is a robot on the ISS aiding the astronauts in their mammoth tasks with a human touch. Intercultural and human robot interaction training is the need of the hour for long duration missions.

Training also has to be evolved for future Moon landings to a human mission to Mars. Factors like crew dynamics, crew size, and crew activities play a crucial role as these missions would last from one year to Moon to three years on Mars. The training required for such missions has to be versatile and easy to learn, adapt, and improvise.

A journey to Mars will require astronauts to remain in the crew capsule for nine months. The monotony and isolation of the journey present new psychological challenges. The long period spent in the crew capsule is comparable to other forms of solitary confinement, such as in submarines or Antarctic bases. Being in an isolated and confined environment generates stress, interpersonal conflict, and other behavioral and mental problems. However, natural scenery and communication with loved ones has shown to relax and lessen these effects. A Network of Social Interactions for Bilateral Life Enhancement (ANSIBLE), which provides natural scenery and socialization in a virtual reality environment, is being researched as a solution to behavioral health.

Researchers are looking into how current mental health tools can be adjusted to help the crew face stressors that will arise in an isolated, confined environment (ICE) during extended missions. The International Space Station uses a behavioral conflict management system known as the Virtual Space Station (VSS) to minimize conflict between crew members and address psychological challenges. The program has modules that focus on relationship management, stress and depression that guide astronaut’s through a virtual therapy session in space.

Virtual reality astronaut training

History

Virtual reality technologies first came to a commercial release in the 1990s. It is not until then did people realize that VR can be used in training astronauts. The earlier VR gears for astronaut training are dedicated to enhance the communication between robot arm operators and the astronaut during Extravehicular Activities (EVA). It brings EVA crew members and robot arm operators together, in live, even when they are on board a spacecraft. It is also used to replace some of the oversized models that cannot fit in the Neutral Buoyancy Lab (NBL).

In 1993, astronauts were trained and evaluated on working on the Hubble Space Telescope through a virtual reality training tool, Research in Human Factors Aspects of Enhanced Virtual Environments for EVA Training and Simulation (RAVEN). However, the aim of RAVEN was not to train astronauts but to evaluate the efficacy of training using virtual reality versus underwater and other setup.

Through the years of technological development in VR, the hardware for the VR Lab in NASA has also significantly improved. Both the material and the resolution of the display are being renovated:

  • 1991: Liquid-Crystal Display (LCD) - 320x420
  • 1992: Cathode Ray Tube (CRT) - 1280x1024
  • 2005: Micro Organic Light-Emitting Diode (micro-OLED) - 800x600
  • 2012: LCD - 1280x720
  • 2015: OLED - 1920x1080

Virtual reality has also been adopted to a much wider range of fields in space exploration throughout the history of technology renovation. The newer applications of VR include but are not limited to:

  • Mission planning
  • Cooperative and interactive designing
  • Engineering problem-solving
  • Data modeling
Astronauts Tom Marshburn, left, and Dave Wolf train for a spacewalk in the Integrated EVA-RMS Virtual Reality Simulator Facility at Johnson Space Center

Current virtual reality training

While the extravehicular activities (EVAs) training facility can simulate the space conditions, including pressure and lighting, the Micro-g environment cannot be fully reconstructed in the Earth’s 1-G environment. Virtual reality is utilized during EVA training to increase the immersion of the training process. NASA Johnson Space Center has facilities such as the Space Vehicle Mockup Facility (SVMF), Virtual Reality Laboratory (VRL), and Neutral Buoyancy Laboratory (NBL).

The SVMF uses the Partial Gravity Simulator (PGS) and air bearing floor (PABF) to simulate the zero-gravity and the effects of Newton's laws of motion. Similar training systems originated from the Apollo and Gemini training. Virtual reality enhances an astronaut’s senses during training modules like fluid quick disconnect operations, spacewalks, and the orbiter’s Space Shuttle thermal protection system (TPS) repairs.

NASA Virtual Reality Laboratory utilizes virtual reality to supplement the Simplified Aid For EVA Rescue (SAFER) as simplified aid. The VR training offers a graphical 3-dimensional simulation of the International Space Station (ISS) with a headset, haptic feedback gloves, and motion tracker. In 2018, two Expedition 55 astronauts Richard R. Arnold and Andrew J. Feustel, received virtual reality training and performed the 210th spacewalk. The Virtual Reality Laboratory offers astronauts an immersive VR experience for spacewalks before launching into space. The training process combines a graphical rendering program that replicates the ISS and a device called the Charlotte Robot that allows astronauts to visually explore their surroundings while interacting with an object.  The Charlotte robot is a simple device with a metal arm attached to the side that allows a user to interact with the device. The user wears haptic feedback gloves with force sensors that send signals to a central computer. In response, the central computer maneuvers the device using a web of cables and calculates how it would act in space through physics. While objects are weightless in space, an astronaut has to be familiar with an object's forces of inertia and understand how the object will respond to simple motions to avoid losing it in space. Training can be completed individually or with a partner. This allows astronauts to learn how to interact with mass and moments of inertia in a microgravity environment.

The Neutral Buoyancy Laboratory (NBL) has advantages in simulating a zero-gravity environment and reproducing the sensation of floating in space. The training method is achieved by constructing a low gravity environment through Maintaining the Natural buoyancy in one of the largest pools in the world. The NBL pool used to practice extravehicular activities or spacewalks is 62 meters (202 feet) long, 31 meters (102 feet) wide, and 12 meters (40 feet) deep, with a capacity of 6.2 million gallons. Underwater head-mounted display virtual reality headset is used to provide visual information during the training with a frame rate of 60 fps and screen resolution of 1280 by 1440. The underwater VR training system has a reduced training cost because of the accessibility of the VR applications, and astronauts need less time to complete the assigned practice task.

Despite the NASA training modules, commercial spaceflight training also uses virtual reality technology to improve their training systems. Boeing’s virtual reality team develops a training system for Boeing Starliner to train astronauts to transport between the Earth and the ISS. The VR training system can simulate high-speed situations and emergency scenarios, for instance, launching, entering the space, and landing at an unexpected location.

Advantages of virtual reality training

Visual reorientation is a phenomenon that happens when the perception of an object changes because of the changing visual field and cues. This illusion will alter the astronaut’s perception of the orienting force of gravity and then lose spatial direction. The astronauts must develop good spatial awareness and orientation to overcome visual reorientation. In the traditional disorientation training, for instance, the Yuri Gagarin Cosmonaut Training Center trains the astronaut by simulating a microgravity environment through a centrifuge. In contrast, VR training requires less gear, training the astronauts more economically.

Virtual reality training utilizes the mix-realistic interaction devices, such as cockpits in flight simulators can reduce the simulation sickness and increase user movement. Compared to traditional training, VR training performs better to minimize the effects of space motion sickness and spatial disorientation. Astronauts who received VR training can perform the task 12% faster, with a 53% decrease in nausea symptoms.

While VR is used in astronaut training on the ground, immersive technology also contributes to on-orbit training. VR head-mounted display can help the astronaut maintain physical well-being as part of proficiency maintenance training. Moreover, VR systems are used to ensure the mental health of the crewmembers. The simulations of social scenarios can mitigate the stress and establish the connectedness under the isolated and confined environment (ICE).

Virtual reality acclimates astronauts to environments in space such as the International Space Station before leaving earth. While astronauts can familiarize themselves with the ISS during training in the NBL, they are only able to see certain sections of the station. While it prepares astronauts for the tasks they are performing in space, it does not necessarily give them a full spatial understanding of the station’s layout. That’s where Virtual Reality plays an important role. The Virtual Reality Lab uses a system known as the Dynamic Onboard Ubiquitous Graphics program (DOUG) to model the ISS’s exterior including decals, fluid lines, and electrical lines, so that the crew can acclimate to their new environment. The level of detail goes beyond the exterior of the station. When a user enters space, they see pure black until their pupil’s dilate and the sky fills with stars in an occurrence called the ‘blooming effect’.

Disadvantages of virtual reality training

While virtual reality prepares astronauts for the unfamiliar tasks they will face in outer space, the training is unable to replicate the psychological and emotional stress that astronauts face on a daily basis. This is because virtual tasks do not hold the same repercussions as the real task and the technology does not produce strong psychological effects, like claustrophobia, that often occurs in enclosed environments.

Stimulating a virtual microgravity environment can be costly due to additional equipment requirements. Unlike commercialized virtual reality, the equipment that NASA uses cannot be produced at a large scale because the systems require supplemental technology. Several VR programs work in combination with the Neutral Buoyancy Lab or the Charlotte Robot in the Virtual Reality Lab which requires expensive facilities and does not eliminate the travel component that VR can minimize. NASA’s Charlotte robot is restricted by cables that simulate the microgravity environment and the Virtual Reality Lab only has two machines in their possession. This particular training system requires a virtual glovebox system (GVX) that has been incorporated into training at NASA and the EVA virtual system at the Astronaut Center of China. Using sensors embedded in the fabric, the gloves can sense when the wearer  decides to  grasp an object or release it, but the technology needs to be further developed to integrate precise user movements into virtual programs. These gloves have been reported to be uncomfortable and only capture limited movements. Full-body motion sensors have also been incorporated into training and tend to be expensive but necessary in order to have effective tactile feedback in response to the astronauts movements. While virtual reality programs have been developed that do not require full-body sensors, the absence reduces the degree to which a user can interact with the virtual world.

Future

The primary focus of future research of virtual reality technologies in space exploration is to develop a method of simulating a microgravity environment. Although it has been a goal since the beginning of VR being used in astronaut training, minor progress has been made. The current setup uses a bungee rope attached to a person’s feet, a swing attached to the body, and finally a head mounted VR display. However, from participants in experiments that use this setup to simulate reduced gravity environments, they only experience the feel of moving around in space with the help of VR, but the experience does not resemble a real zero-gravity environment in outer space. Specifically, the pressure from the bungee rope and the swing because of the participants’ own weight creates an unreal and unpleasant feeling. The current technology may be enough for the general public to experience what moving around in space is like, but it is still far from being formally used as an astronaut training tool.

These efforts of simulating micro-gravity serve a similar purpose of creating an increasingly immersive environment for astronaut training. In fact, this is a developing trend for the entire VR industry. The ultimate scene VR experience that we are imagining will eventually be marked by the elimination between the real and the virtual world.

Lie point symmetry

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