title: Video game crash of 1983

text: A massive industry shakeout resulted. Magnavox abandoned the video game business entirely. Imagic withdrew its IPO the day before its stock was to go public; the company later collapsed. Activision had to downsize across 1984 and 1985 due to loss of revenue, and to stay competitive and maintain financial security, began development of games for the personal computer. Within a few years, Activision no longer produced cartridge-based games and focused solely on personal computer games.


title: Video game crash of 1983

text: Atari was one of those companies most affected by the crash. As a company, its revenues dropped significantly due to dramatically lower sales and cost of returned stock. By mid-1983, the company had lost and was forced to lay off 3,000 of its 10,000 worker staff. Unsold "Pac-Man", "E.T. the Extra-Terrestrial", and other 1982 and 1983 games and consoles started to fill their warehouses. In September 1983, Atari discreetly buried much of this excess stock in a landfill near Alamogordo, New Mexico, though Atari did not comment about their activity at the time. Misinformation related to sales of "Pac-Man" and "E.T." led to an urban legend of the Atari video game burial that millions of unsold cartridges were buried there. Gaming historians received permission to dig up the landfill as part of a documentary in 2014, during which former Atari executive James Heller, who had overseen the original burial clarified that only about 728,000 cartridges had been buried in 1982, backed by estimates made during the excavation, and disproving the scale of the urban legend. Atari's burial remains an iconic representation of the 1983 video game crash. By the end of 1983, Atari had over in losses, leading to Warner Communication to sell Atari's consumer products division in July 1984 to Jack Tramiel, who had recently departed Commodore International. Tramiel's new company took the name Atari Corporation, and the directed their efforts into developing their new personal computer line, the Atari ST, over the console business.


title: Video game crash of 1983

text: Lack of confidence in the video game sector caused many retailers to stop selling video game consoles or reduced their stock significantly, reserving floor or shelf space for other products. Retailers established to exclusively sell video games folded, which impacted sales of personal computer games.


title: Video game crash of 1983

text: The crash also affected video game arcades, which had had several years of a golden age since the introduction of "Space Invaders" in 1978 but was waning by 1983 due to the expansion of home consoles, the lack of novel games, and undue attention to teenage delinquency around video game arcades. While the number of arcades in the United States had doubled to 10,000 from 1980 to 1982, the crash led to a closure of around 1,500 arcades, and revenues of those that remained open had fallen by 40%.


title: Video game crash of 1983

text: The full effects of the industry crash were not felt until 1985. Despite Atari's claim of 1 million in worldwide sales of its 2600 game system that year, recovery was slow. The sales of home video games had dropped from $3.2 billion in 1982 to $100 million in 1985. Analysts doubted the long-term viability of the video game industry, and, according to Electronic Arts' Trip Hawkins, it had been very difficult to convince retailers to carry video games due to the stigma carried by the fall of Atari until 1985.


title: Video game crash of 1983

text: Two major events of 1985 helped to revitalize the video game industry. One factor came from increased sales of personal computers from Commodore and Tandy, which helped to maintain revenue for game developers like Activision and Electronic Arts, keeping the video game market alive. The other was the initial limited release of the Nintendo Entertainment System in North America in autumn 1985, followed by the full national release the following spring. Following 1986, the industry began recovering, and by 1988, annual sales in the industry exceeding $2.3 billion with 70% of the market dominated by Nintendo. In 1986, Nintendo president Hiroshi Yamauchi noted that "Atari collapsed because they gave too much freedom to third-party developers and the market was swamped with rubbish games". In response, Nintendo limited the number of titles that third-party developers could release for their system each year, and promoted its "Seal of Quality", which it allowed to be used on games and peripherals by publishers that met Nintendo's quality standards.


title: Video game crash of 1983

text: The end of the crash allowed Commodore to raise the price of the C64 for the first time upon the June 1986 introduction of the Commodore 64c—a Commodore 64 redesigned for lower cost of manufacture—which "Compute!" cited as the end of the home-computer price war, one of the causes of the crash.


title: Video game crash of 1983

text: The crash in 1983 had the largest impact in the United States, and rippled through all sectors of the global video game market worldwide, though sales of video games still remained strong in Japan, Europe, and Canada from the beleaguered American companies. It took several years for the U.S. industry to recover. The estimated worldwide market in 1982, including arcade, console, and computer games, dropped to by 1985. There was also a significant shift in the home video game market, away from consoles to personal computer software, between 1983 and 1985.


title: Video game crash of 1983

text: 1984 is when some of the longer-term effects started to take a toll on the video game console. Companies like Magnavox had decided to pull out of the video game console industry. The general consensus was that video games were just a fad that came as quickly as they left. But outside of North America the video game industry was doing very well. Home consoles were growing in popularity in Japan while home computers were surging across Europe.


title: Video game crash of 1983

text: United States sales fell from $3 billion to around $100 million in 1985. Despite the decline, new gaming companies started to make their way onto the scene such as Westwood Studios, Code Masters, and SquareSoft, which all started in 1985. All of these companies would go on to create numerous genre-defining titles in the future. During the holiday season of 1985 Hiroshi Yamauchi decided to go to New York small markets about putting their products in their stores. Minoru Arakawa offered a money back guarantee from Nintendo that they would pay back for any stock that was left unsold. In total Nintendo sold 50,000 units, about half of the units they shipped to the US.


title: Video game crash of 1983

text: The U.S. video game crash had two long-lasting results. The first result was that dominance in the home console market shifted from the United States to Japan. The crash did not directly affect the financial viability of the video game market in Japan, but it still came as a surprise there and created repercussions that changed that industry, and thus became known as the "Atari shock".


title: Video game crash of 1983

text: Prior to the crash, Jonathan Greenberg of "Forbes" had predicted in early 1981 that Japanese companies would eventually dominate the North American video game industry, as American video game companies were increasingly licensing products from Japanese companies, who in turn were opening up North American branches. By 1982–1983, Japanese manufacturers had captured a large share of the North American arcade market, which Gene Lipkin of Data East USA partly attributed to Japanese companies having more finances to invest in new ideas.


title: Video game crash of 1983

text: As the crash was happening in the United States, Japan's game industry started to shift its attention from arcade games to home consoles. Within one month in 1983, two new home consoles were released in Japan: the Nintendo Family Computer (Famicom) and Sega's SG-1000 (which was later supplanted by the Master System) heralding the third generation of home consoles retrospectively. These two consoles were very popular, buoyed by an economic bubble in Japan. The units readily outsold Atari and Mattel's existing systems, and with both Atari and Mattel focusing on recovering domestic sales, the Japanese consoles effectively went uncontested over the next few years. By 1986, three years after its introduction, 6.5 million Japanese homes – 19% of the population – owned a Famicom, and Nintendo began exporting it to the U.S., where the home console industry was only just recovering from the crash.


title: Video game crash of 1983

text: The impact on the retail sector of the crash was the most formidable barrier that confronted Nintendo as it tried to market the Famicom in the United States. Retailer opposition to video games was directly responsible for causing Nintendo to brand its product the Nintendo Entertainment System (NES) rather than a "video game system", and using terms such as "control deck" and "Game Pak", as well as producing a toy robot called R.O.B. to convince toy retailers to allow it in their stores. Furthermore, the design for the NES used a front-loading cartridge slot to mimic how video cassette recorders, popular at that time, were loaded, further pulling the NES away from previous console designs.


title: Video game crash of 1983

text: By the time the U.S. video game market recovered in the late 1980s, the NES was by far the dominant console in the United States, leaving only a fraction of the market to Atari. By 1989, home video game sales in the United States had reached $5 billion, surpassing the 1982 peak of $3 billion during the previous generation. A large majority of the market was controlled by Nintendo; it sold more than 35 million units in the United States, exceeding the sales of other consoles and personal computers by a considerable margin. New Japanese companies entered the market to challenge Nintendo's success in the United States, NEC's TurboGrafx-16 and the Sega Genesis, both released in the U.S. in 1989. While the TurboGrafx underwhelmed in the market, the Genesis's release set the stage for a major rivalry between Sega and Nintendo in the early 1990s in the United States video game market.


title: Video game crash of 1983

text: A second, highly visible result of the crash was the advancement of measures to control third-party development of software. Using secrecy to combat industrial espionage had failed to stop rival companies from reverse engineering the Mattel and Atari systems and hiring away their trained game programmers. While Mattel and Coleco implemented lockout measures to control third-party development (the ColecoVision BIOS checked for a copyright string on power-up), the Atari 2600 was completely unprotected and once information on its hardware became available, little prevented anyone from making games for the system. Nintendo thus instituted a strict licensing policy for the NES that included equipping the cartridge and console with lockout chips, which were region-specific, and had to match in order for a game to work. In addition to preventing the use of unlicensed games, it also was designed to combat software piracy, rarely a problem in North America or Western Europe, but rampant in East Asia. The concepts of such a control system remain in use on every major video game console produced today, even with fewer "cartridge-based" consoles on the market than in the 8/16-bit era. Replacing the security chips in most modern consoles are specially encoded optical discs that cannot be copied by most users and can only be read by a particular console under normal circumstances.


title: Video game crash of 1983

text: Accolade achieved a technical victory in one court case against Sega, challenging this control, even though it ultimately yielded and signed the Sega licensing agreement. Several publishers, notably Tengen (Atari Games), Color Dreams, and Camerica, challenged Nintendo's control system during the 8-bit era by producing unlicensed NES games.


title: Video game crash of 1983

text: Initially, Nintendo was the only developer for the Famicom. Under pressure from Namco and Hudson Soft, it opened the Famicom to third-party development, but instituted a license fee of 30% per game cartridge for these third-parties to develop games, a system used by console manufactures to this day. Nintendo maintained strict manufacturing control and requiring payment in full before manufacturing. Cartridges could not be returned to Nintendo, so publishers assumed all the financial risk of selling all units ordered. Nintendo limited most third-party publishers to only five games per year on its systems (some companies tried to get around this by creating additional company labels like Konami's Ultra Games label). Nintendo ultimately dropped this rule by 1993, after the release of the successor Super Nintendo Entertainment System. Nintendo's strong-armed oversight of Famicom cartridge manufacturing led to both legitimate and bootleg unlicensed cartridges to be made in the Asian regions. Nintendo placed its Nintendo Seal of Quality on all licensed games released for the system to try to promote authenticity and detract from bootleg sales, but failed to make significant traction to stalling these sales.


title: Video game crash of 1983

text: As Nintendo prepared to release the Famicom in the United States, it wanted to avoid both the bootleg problem it had in Asia as well as the mistakes that led up to the 1983 crash. The company created the proprietary 10NES system, a lockout chip which was designed to prevent cartridges made without the chip from being played on the NES. The 10NES lockout was not perfect, as later in the NES's lifecycle methods were found to bypass it, but it did sufficiently allow Nintendo to strengthen its publishing control to avoid the mistakes Atari had made and initially prevent bootleg cartridges in the Western markets. These strict licensing measures backfired somewhat after Nintendo was accused of monopolistic behavior. In the long run, this pushed many western third-party publishers such as Electronic Arts away from Nintendo consoles and supported competing consoles such as the Sega Genesis or Sony PlayStation. Most of the Nintendo platform-control measures were adopted by later console manufacturers such as Sega, Sony, and Microsoft, although not as stringently.


title: Video game crash of 1983

text: With waning console interests in the United States, the computer game market was able to gain a strong foothold in 1983 and beyond. Developers that had been primarily in the console games space, like Activision, turned their attention to developing computer game titles to stay viable. Newer companies also were founded to capture the growing interest in the computer games space with novel elements that borrowed from console games, as well as taking advantage of low-cost dial-up modems that allowed for multiplayer capabilities. The computer game market grew between 1983 and 1984, overtaking the console market, but overall video game revenues had declined significantly due to the considerable decline of the console market as well as the arcade market to an extent. The home computer industry, however, experienced a downturn in mid-1984, with global computer game sales declining in 1985 to a certain extent.


title: Video game crash of 1983

text: Microcomputers dominated the European market throughout the 1980s and with domestic production for those formats thriving over the same period, there was minimal trans-Atlantic ripple from American game production and trends. Partly as a distant knock-on effect of the crash and partly due to the continuing quality of homegrown computer and microcomputer games, consoles did not achieve a dominant position in some European markets until the early 1990s. In the United Kingdom, there was a short-lived home console market between 1980 and 1982, but the 1983 crash led to the decline of consoles in the UK, which was offset by the rise of LCD games in 1983 and then the rise of computer games in 1984. It was not until the late 1980s with the arrival of the Master System and NES that the home console market recovered in the UK. Computer games remained the dominant sector of the UK home video game market up until they were surpassed by Sega and Nintendo consoles in 1991.


title: Sunscreen

text: Sunscreen, also known as sunblock or sun cream, is a photoprotective topical product for the skin that mainly absorbs, or to a much lesser extent reflects, some of the sun's ultraviolet (UV) radiation and thus helps protect against sunburn and most importantly prevent skin cancer. Sunscreens come as lotions, sprays, gels, foams (such as an expanded foam lotion or whipped lotion), sticks, powders and other topical products. Sunscreens are common supplements to clothing, particularly sunglasses, sunhats and special sun protective clothing, and other forms of photoprotection (such as umbrellas).


title: Sunscreen

text: The first sunscreen in the world was invented in Australia, by chemist H.A. Milton Blake, in 1932 formulating with the UV filter 'salol' (phenyl salicylate) at a concentration of 10%. Its protection was verified by the University of Adelaide and it was also produced commercially by Blake's company, Hamilton Laboratories. Despite sunscreen being relatively new, sun protection practices have been observed since at least the ancient Egyptians "who used ingredients such as rice bran, jasmine, and lupine" to provide sun protection.


title: Sunscreen

text: Sunscreens are classified into mineral (also referred to as physical) sunscreens (i.e., zinc oxide and titanium dioxide) and chemical (also referred to as petrochemical, as they are typically derived from petroleum) sunscreens.


title: Sunscreen

text: Research by the FDA on the safety of the main three organic UV filters (oxybenzone, homosalate and octocrylene) found that the three ingredients could be detected on the skin, in blood, in breast milk and in urine samples weeks after no longer being used.


title: Sunscreen

text: Medical organizations such as the American Cancer Society recommend the use of sunscreen because it aids in the prevention of squamous cell carcinomas. The routine use of sunscreens may also reduce the risk of melanoma. However, many sunscreens do not block ultraviolet A (UVA) radiation, yet protection from UVA is important for the prevention of skin cancer.


title: Sunscreen

text: To provide a better indication of their ability to protect against skin cancer and other diseases associated with UVA radiation (such as phytophotodermatitis), the use of broad-spectrum (UVA/UVB) sunscreens has been recommended.


title: Sunscreen

text: In the United States, sunscreens are required to remain effective at original strength for at least three years. Some sunscreens include an expiration date—a date indicating when they may become less effective.


title: Sunscreen

text: Sunscreen use can help prevent melanoma and squamous cell carcinoma, two types of skin cancer. There is little evidence that it is effective in preventing basal cell carcinoma.


title: Sunscreen

text: A 2013 study concluded that the diligent, everyday application of sunscreen could slow or temporarily prevent the development of wrinkles and sagging skin. The study involved 900 white people in Australia and required some of them to apply a broad-spectrum sunscreen every day for four and a half years. It found that people who did so had noticeably more resilient and smoother skin than those assigned to continue their usual practices. A study on 32 subjects showed that daily use of sunscreen (SPF 30) reversed photoaging of the skin within 12 weeks and the amelioration continued until the end of the investigation period of one year. Sunscreen is inherently anti-ageing as the sun is the number one cause of premature ageing, it therefore may slow or temporarily prevent the development of wrinkles, dark spots and sagging skin.


title: Sunscreen

text: Minimizing UV damage is especially important for children and fair-skinned individuals and those who have sun sensitivity for medical reasons.


title: Sunscreen

text: As of 2021, only Zinc Oxide and Titanium Dioxide are recognised as safe and effective (GRASE) by the U.S. Food and Drug Administration (FDA), as currently there is insufficient safety data to support petrochemicals being safe, such as oxybenzone and avobenzone. "A survey of 1000 Australians from 18 to over 76 years old, commissioned by Cancer Council, found that nearly half of respondents believed that sunscreen contained chemicals that were bad for you and could even cause cancer."


title: Sunscreen

text: In 2009, the Therapeutic Goods Administration of Australia updated a review of sunscreen safety studies and concluded: "The potential for titanium dioxide (TiO) and zinc oxide (ZnO) nanoparticles in sunscreens to cause adverse effects depend primarily upon the ability of the nanoparticles to reach viable skin cells. To date, the current weight of evidence suggests that TiO and ZnO nanoparticles do not reach viable skin cells." Many petrochemical based sunscreen ingredients have already been banned over safety concerns (petrochemicals such as PABA).


title: Sunscreen

text: There is a risk of an allergic reaction to sunscreen for some individuals, as "Typical allergic contact dermatitis may occur in individuals allergic to any of the ingredients that are found in sunscreen products or cosmetic preparations that have a sunscreen component. The rash can occur anywhere on the body where the substance has been applied and sometimes may spread to unexpected sites."


title: Sunscreen

text: There are some concerns about potential vitamin D deficiency arising from prolonged use of sunscreen. The typical use of sunscreen does not usually result in vitamin D deficiency; however, extensive usage may. Sunscreen prevents ultraviolet light from reaching the skin, and even moderate protection can substantially reduce vitamin D synthesis. However, adequate amounts of vitamin D can obtained via diet or supplements. Vitamin D overdose is impossible from UV exposure due to an equilibrium the skin reaches in which vitamin D degrades as quickly as it is created.


title: Sunscreen

text: Studies showed that sunscreen with a high UVA protection factor enabled significantly higher vitamin D synthesis than a low UVA protection factor sunscreen, likely because it allows more UVB transmission.


title: Sunscreen

text: The sun protection factor (SPF rating, introduced in 1974) is a measure of the fraction of sunburn-producing UV rays that reach the skin. For example, "SPF 15" means that of the burning radiation will reach the skin, assuming sunscreen is applied evenly at a thick dosage of 2 milligrams per square centimeter (mg/cm). It is important to note that sunscreens with higher SPF do not last or remain effective on the skin any longer than lower SPF and must be continually reapplied as directed, usually every two hours.


title: Sunscreen

text: The SPF is an imperfect measure of skin damage because invisible damage and skin malignant melanomas are also caused by ultraviolet A (UVA, wavelengths 315–400 or 320–400 nm), which does not primarily cause reddening or pain. Conventional sunscreen blocks very little UVA radiation relative to the nominal SPF; broad-spectrum sunscreens are designed to protect against both UVB and UVA. According to a 2004 study, UVA also causes DNA damage to cells deep within the skin, increasing the risk of malignant melanomas. Even some products labeled "broad-spectrum UVA/UVB protection" have not always provided good protection against UVA rays. Titanium dioxide probably gives good protection, but does not completely cover the UVA spectrum, as early 2000s research suggests that zinc oxide is superior to titanium dioxide at wavelengths 340–380 nm.


title: Sunscreen

text: Owing to consumer confusion over the real degree and duration of protection offered, labeling restrictions are enforced in several countries. In the EU, sunscreen labels can only go up to SPF 50+ (initially listed as 30 but soon revised to 50). Australia's Therapeutic Goods Administration increased the upper limit to 50+ in 2012. In its 2007 and 2011 draft rules, the US Food and Drug Administration (FDA) proposed a maximum SPF label of 50, to limit unrealistic claims. (As of February 2017, the FDA has not adopted the SPF 50 limit.) Others have proposed restricting the active ingredients to an SPF of no more than 50, due to lack of evidence that higher dosages provide more meaningful protection. Different sunscreen ingredients have different effectiveness against UVA and UVB.


title: Sunscreen

text: The SPF can be measured by applying sunscreen to the skin of a volunteer and measuring how long it takes before sunburn occurs when exposed to an artificial sunlight source. In the US, such an "in vivo" test is required by the FDA. It can also be measured "in vitro" with the help of a specially designed spectrometer. In this case, the actual transmittance of the sunscreen is measured, along with the degradation of the product due to being exposed to sunlight. In this case, the transmittance of the sunscreen must be measured over all wavelengths in sunlight's UVB–UVA range (290–400 nm), along with a table of how effective various wavelengths are in causing sunburn (the "erythemal action spectrum") and the standard intensity spectrum of sunlight (see the figure). Such "in vitro" measurements agree very well with "in vivo" measurements.


title: Sunscreen

text: Numerous methods have been devised for evaluation of UVA and UVB protection. The most-reliable spectrophotochemical methods eliminate the subjective nature of grading erythema.


title: Sunscreen

text: The ultraviolet protection factor (UPF) is a similar scale developed for rating fabrics for sun protective clothing. According to recent testing by "Consumer Reports", UPF ~30+ is typical for protective fabrics, while UPF ~20 is typical for standard summer fabrics.


title: Sunscreen

text: where formula_2 is the solar irradiance spectrum, formula_3 the erythemal action spectrum, and formula_4 the monochromatic protection factor, all functions of the wavelength formula_5. The MPF is roughly the inverse of the transmittance at a given wavelength.


title: Sunscreen

text: The above means that the SPF is not simply the inverse of the transmittance in the UVB region. If that were true, then applying two layers of SPF 5 sunscreen would always be equivalent to SPF 25 (5 times 5). The actual combined SPF may be lower than the square of the single-layer SPF.


title: Sunscreen

text: The persistent pigment darkening (PPD) method is a method of measuring UVA protection, similar to the SPF method of measuring sunburn protection. Originally developed in Japan, it is the preferred method used by manufacturers such as L'Oréal.


title: Sunscreen

text: Instead of measuring erythema, the PPD method uses UVA radiation to cause a persistent darkening or tanning of the skin. Theoretically, a sunscreen with a PPD rating of 10 should allow a person 10 times as much UVA exposure as would be without protection. The PPD method is an "in vivo" test like SPF. In addition, the European Cosmetic and Perfumery Association ("Colipa") has introduced a method that, it is claimed, can measure this "in vitro" and provide parity with the PPD method.


title: Sunscreen

text: As part of revised guidelines for sunscreens in the EU, there is a requirement to provide the consumer with a minimum level of UVA protection in relation to the SPF. This should be a UVA protection factor of at least 1/3 of the SPF to carry the UVA seal. The 1/3 threshold derives from the European Commission recommendation 2006/647/EC. This Commission recommendation specifies that the UVA protection factor should be measured using the PPD method as modified by the French health agency AFSSAPS (now ANSM) "or an equivalent degree of protection obtained with any in vitro method".


title: Sunscreen

text: A set of final US FDA rules effective from summer 2012 defines the phrase "broad spectrum" as providing UVA protection proportional to the UVB protection, using a standardized testing method.


title: Sunscreen

text: In the UK and Ireland, the Boots star rating system is a proprietary "in vitro" method used to describe the ratio of UVA to UVB protection offered by sunscreen creams and sprays. Based on original work by Brian Diffey at Newcastle University, the Boots Company in Nottingham, UK, developed a method that has been widely adopted by companies marketing these products in the UK.


title: Sunscreen

text: One-star products provide the lowest ratio of UVA protection, five-star products the highest. The method was revised in light of the Colipa UVA PF test and the revised EU recommendations regarding UVA PF. The method still uses a spectrophotometer to measure absorption of UVA versus UVB; the difference stems from a requirement to pre-irradiate samples (where this was not previously required) to give a better indication of UVA protection and photostability when the product is used. With the current methodology, the lowest rating is three stars, the highest being five stars.


title: Sunscreen

text: In August 2007, the FDA put out for consultation the proposal that a version of this protocol be used to inform users of American product of the protection that it gives against UVA; but this was not adopted, for fear it would be too confusing.


title: Sunscreen

text: Asian brands, particularly Japanese ones, tend to use The Protection Grade of UVA (PA) system to measure the UVA protection that a sunscreen provides. The PA system is based on the PPD reaction and is now widely adopted on the labels of sunscreens. According to the Japan Cosmetic Industry Association, PA+ corresponds to a UVA protection factor between two and four, PA++ between four and eight, and PA+++ more than eight. This system was revised in 2013 to include PA++++ which corresponds to a PPD rating of sixteen or above.


title: Sunscreen

text: Sunblock typically refers to opaque sunscreen that is effective at blocking both UVA and UVB rays and uses a heavy carrier oil to resist being washed off. Titanium dioxide and zinc oxide are two minerals that are used in sunblock.


title: Sunscreen

text: The use of the word "sunblock" in the marketing of sunscreens is controversial. Since 2013, the FDA has banned such use because it can lead consumers to overestimate the effectiveness of products so labeled. Nonetheless, many consumers use the words sunblock and sunscreen synonymously.


title: Sunscreen

text: For total protection against damage from the sun, the skin needs to be protected from UVA, UVB, and also IRA (infrared-A light). Infrared radiation accounts for roughly 40% of solar energy at sea level. There is continuing debate within the dermatology community over the impact of sun-sourced IRA: Some sources indicate that early morning IRA exposure may be protective against further sun exposure by increasing cell proliferation and initiating anti-inflammatory cascades; these effects are not observed for artificial sources of intense IRA.


title: Sunscreen

text: In addition to moisturizers and other inactive ingredients, sunscreens contain one or more of the following active ingredients, which are either organic or mineral in nature:


title: Sunscreen

text: The principal active ingredients in sunscreens are usually aromatic molecules conjugated with carbonyl groups. This general structure allows the molecule to absorb high-energy ultraviolet rays and release the energy as lower-energy rays, thereby preventing the skin-damaging ultraviolet rays from reaching the skin. So, upon exposure to UV light, most of the ingredients (with the notable exception of avobenzone) do not undergo significant chemical change, allowing these ingredients to retain the UV-absorbing potency without significant photodegradation. A chemical stabilizer is included in some sunscreens containing avobenzone to slow its breakdown; examples include formulations containing. The stability of avobenzone can also be improved by bemotrizinol, octocrylene and various other photostabilisers. Most organic compounds in sunscreens slowly degrade and become less effective over the course of several years even if stored properly, resulting in the expiration dates calculated for the product.


title: Sunscreen

text: Sunscreening agents are used in some hair care products such as shampoos, conditioners and styling agents to protect against protein degradation and color loss. Currently, benzophenone-4 and ethylhexyl methoxycinnamate are the two sunscreens most commonly used in hair products. The common sunscreens used on skin are rarely used for hair products due to their texture and weight effects.


title: Sunscreen

text: Other ingredients approved within the EU and other parts of the world, that have not been included in the current FDA Monograph:


title: Sunscreen

text: Many of the ingredients awaiting approval by the FDA are relatively new, and developed to absorb UVA. The 2014 Sunscreen Innovation Act was passed to accelerate the FDA approval process.


title: Sunscreen

text: It is known that SPF is affected by not only the choice of active ingredients and the percentage of active ingredients but also the formulation of the vehicle/base. Final SPF is also impacted by the distribution of active ingredients in the sunscreen, how evenly the sunscreen applies on the skin, how well it dries down on the skin and the pH value of the product among other factors. Changing any inactive ingredient may potentially alter a sunscreen's SPF.


title: Sunscreen

text: When combined with UV filters, added antioxidants can work synergistically to affect the overall SPF value positively. Furthermore, adding antioxidants to sunscreen can amplify its ability to reduce markers of extrinsic photoaging, grant better protection from UV induced pigment formation, mitigate skin lipid peroxidation, improve the photostability of the active ingredients, neutralize reactive oxygen species formed by irradiated photocatalysts "(eg., uncoated TiO₂)" and aid in DNA repair post-UVB damage, thus enhancing the efficiency and safety of sunscreens. Compared with sunscreen alone, it has been shown that the addition of antioxidants has the potential to suppress ROS formation by an additional 1.7-fold for SPF 4 sunscreens and 2.4-fold for SPF 15-to-SPF 50 sunscreens, but the efficacy depends on how well the sunscreen in question has been formulated. Sometimes osmolytes are also incorporated into commercially available sunscreens in addition to antioxidants since they also aid in protecting the skin from the detrimental effects of UVR. Examples include the osmolyte taurine, which has demonstrated the ability to protects against UVB-radiation induced immunosuppression and the osmolyte ectoine, which aids in counteracting cellular accelerated aging & UVA-radiation induced premature photoaging.


title: Sunscreen

text: Other inactive ingredients can also assist in photostabilizing unstable UV filters. Cyclodextrins have demonstrated the ability to reduce photodecomposition, protect antioxidants and limit skin penetration past the uppermost skin layers, allowing them to longer maintain the protection factor of sunscreens with UV filters that are highly unstable and/or easily permeate to the lower layers of the skin. Similarly, film-forming polymers like polyester-8 and polycryleneS1 have the ability to protect the efficacy of older organic UV filters by preventing them from destabilizing due to extended light exposure. These kinds of ingredients also increase the water resistance of sunscreen formulations.


title: Sunscreen

text: In the 2010s & 2020s there has been increasing interest in sunscreens that protect the wearer from the sun's HEVL & Infrared light as well as ultraviolet light. This is due to newer research revealing blue & violet visible light and certain wavelengths of infrared light "(eg., NIR, IR-A)" work synergistically with UV light in contributing to oxidative stress, free radical generation, dermal cellular damage, suppressed skin healing, decreased immunity, erythema, inflammation, dryness, and several aesthetic concerns, such as: wrinkle formation, loss of skin elasticity and dyspigmentation. Increasingly, a number of commercial sunscreens are being produced that have manufacturer claims regarding skin protection from blue light, infrared light and even air pollution. However, as of 2021 there are no regulatory guidelines or mandatory testing protocols that govern these claims. Historically, the American FDA has only recognized protection from sunburn "(via UVB protection)" and protection from skin cancer "(via SPF 15+ with some UVA protection)" as drug/medicinal sunscreen claims, so they do not have regulatory authority over sunscreen claims regarding protecting the skin from damage from these other environmental stressors. Since sunscreen claims not related to protection from ultraviolet light are treated as cosmeceutical claims rather than drug/medicinal claims, the innovative technologies and additive ingredients used to allegedly reduce the damage from these other environmental stressors may vary widely from brand to brand.


title: Sunscreen

text: Some studies show that mineral sunscreens primarily made with substantially large particles "(ie.,neither nano nor micronized)" may help protect from visible and infrared light to some degree, but these sunscreens are often unacceptable to consumers due to leaving an obligatory opaque white cast on the skin. Further research has shown that sunscreens with added iron oxide pigments and/or pigmentary titanium dioxide can provide the wearer with a substantial amount of HEVL protection. Cosmetic chemists have found that other cosmetic-grade pigments can be functional filler ingredients. Mica was discovered to have significant synergistic effects with UVR filters when formulated in sunscreens, in that it can notably increase the formula's ability to protect the wearer from HEVL.


title: Sunscreen

text: There is a growing amount of research demonstrating that adding various vitamer antioxidants "(eg; retinol, alpha tocopherol, gamma tocopherol, tocopheryl acetate, ascorbic acid, ascorbyl tetraisopalmitate, ascorbyl palmitate, sodium ascorbyl phosphate, ubiquinone)" and/or a mixture of certain botanical antioxidants "(eg; epigallocatechin-3-gallate, b-carotene, vitis vinifera, silymarin, spirulina extract, chamomile extract and possibly others)" to sunscreens efficaciously aids in reducing damage from the free radicals produced by exposure to solar ultraviolet radiation, visible light, near infrared radiation and infrared-a radiation. Since sunscreen's active ingredients work preventatively by creating a shielding film on the skin that absorbs, scatters, and reflects light before it can reach the skin, UV filters have been deemed an ideal “first line of defense” against sun damage when exposure can't be avoided. Antioxidants have been deemed a good “second line of defense” since they work responsively by decreasing the overall burden of free radicals that do reach the skin. The degree of the free radical protection from the entire solar spectral range that a sunscreen can offer has been termed the “radical protection factor” (RPF) by some researchers.


title: Sunscreen

text: SPF 30 or above must be used to effectively prevent UV rays from damaging skin cells. This is the amount that is recommended to prevent against skin cancer. Sunscreen must also be applied thoroughly and re-applied during the day, especially after being in the water. Special attention should be paid to areas like the ears and nose, which are common spots of skin cancer. Dermatologists may be able to advise about what sunscreen is best to use for specific skin types.


title: Sunscreen

text: The dose used in FDA sunscreen testing is 2 mg/cm of exposed skin. If one assumes an "average" adult build of height 5 ft 4 in (163 cm) and weight 150 lb (68 kg) with a 32-inch (82-cm) waist, that adult wearing a bathing suit covering the groin area should apply approximately 30 g (or 30 ml, approximately 1 oz) evenly to the uncovered body area. This can be more easily thought of as a "golf ball" size amount of product per body, or at least six teaspoonfuls. Larger or smaller individuals should scale these quantities accordingly. Considering only the face, this translates to about 1/4 to 1/3 of a teaspoon for the average adult face.


title: Sunscreen

text: Some studies have shown that people commonly apply only 1/4 to 1/2 of the amount recommended for achieving the rated sun protection factor (SPF), and in consequence the effective SPF should be downgraded to a 4th root or a square root of the advertised value, respectively. A later study found a significant exponential relation between SPF and the amount of sunscreen applied, and the results are closer to linearity than expected by theory.<ref name="DOI10.1111/j.1600-0781.2009.00408.x"></ref>


title: Sunscreen

text: Claims that substances in pill form can act as sunscreen are false and disallowed in the United States.


title: Sunscreen

text: On 1 January 2020, Palau became the first country in the world to ban sun cream that is harmful to corals and sea life. The ban came into effect immediately after an announcement by President Tommy Remengesau Jr.


title: Sunscreen

text: Sunscreen labeling standards have been evolving in the United States since the FDA first adopted the SPF calculation in 1978. The FDA issued a comprehensive set of rules in June 2011, taking effect in 2012–2013, designed to help consumers identify and select suitable sunscreen products offering protection from sunburn, early skin aging, and skin cancer:


title: Sunscreen

text: In 2019, the FDA proposed tighter regulations on sun protection and general safety, including the requirement that sunblock products with SPF greater than 15 must be broad spectrum and a prohibition on products with SPF greater than 60.


title: Sunscreen

text: The state of Hawaii banned the commercial sale of sunscreens containing oxybenzone and octinoxate on January 1, 2021 due to concern of environmental effects linked to the two ingredients and their contribution to increased coral bleaching. This ban is only applicable to sale within the state and to sunscreen products, not other cosmetic materials.


title: Sunscreen

text: Sunscreen can be purchased using a tax-advantaged health savings account (HSA) or flexible spending account (FSA) in the United States.


title: Sunscreen

text: Certain sunscreens in water under ultraviolet light can increase the production of hydrogen peroxide, which damages phytoplankton.


title: Sunscreen

text: A 2002 study suggests that sunscreen causes an increase in virus abundance in seawater, leading to poor marine environment health similar to that of other pollutants.


title: Sunscreen

text: A 2008 study that tested different sunscreen brands, protective factors, and concentrations found that they all caused bleaching on hard corals, and the rate of bleaching increased with increased quantity of sunscreen. Of the compounds found in sunscreen that were tested separately, "butylparaben, ethylhexylmethoxycinnamate, benzophenone-3 and 4-methylbenzylidene camphor caused complete bleaching even at very low concentrations."


title: Sunscreen

text: Media reports link oxybenzone in sunscreens to coral bleaching, although some environmental experts dispute the claim. A 2015 study published in the "Archives of Environmental Contamination and Toxicology" linked oxybenzone to effects on cell culture experiments and juvenile coral, but other sources of pollution such as agricultural run-off and sewage probably have a larger impact on coral reefs.


title: Sunscreen

text: In 2018, the Pacific nation of Palau has become the first country to ban sun creams containing oxybenzone, octinoxate, and some other harmful elements.


title: Sunscreen

text: A 2019 study of UV filters in oceans found far lower concentrations of oxybenzone than previously reported, and lower than known thresholds for environmental toxicity. Additionally, the National Oceanic and Atmospheric Administration (NOAA) has indicated that coral decline is associated with effects from climate change (warming oceans, rising water levels, acidification), overfishing, and pollution from agriculture, wastewater, and urban run-off.


title: Sunscreen

text: Early civilizations used a variety of plant products to help protect the skin from sun damage. For example, ancient Greeks used olive oil for this purpose, and ancient Egyptians used extracts of rice, jasmine, and lupine plants whose products are still used in skin care today. Zinc oxide paste has also been popular for skin protection for thousands of years. Among the nomadic sea-going Sama-Bajau people of the Philippines, Malaysia, and Indonesia, a common type of sun protection is a paste called "borak" or "burak", which was made from water weeds, rice and spices. It is used most commonly by women to protect the face and exposed skin areas from the harsh tropical sun at sea. In Myanmar, thanaka, a yellow-white cosmetic paste made of ground bark, is traditionally used for sun protection.


title: Sunscreen

text: The first ultraviolet B filters were produced in 1928. Followed by the first sunscreen, invented in Australia by chemist H.A. Milton Blake, in 1932 formulating with the UV filter 'salol' (Phenyl salicylate) at a concentration of 10%. Its protection was verified by the University of Adelaide. In 1936, L'Oreal released its first sunscreen product, formulated by French chemist Eugène Schueller.


title: Sunscreen

text: Early adopters of sunscreen were the US military. In 1944, as the hazards of sun overexposure became apparent to soldiers stationed in the Pacific tropics at the height of World War II, Benjamin Green, an airman and later a pharmacist produced Red Vet Pet (for red veterinary petrolatum) for the US military. Sales boomed when Coppertone improved and commercialized the substance under the Coppertone girl and Bain de Soleil branding in the early 1950s. In 1946, Austrian chemist Franz Greiter introduced a product, called "Gletscher Crème" (Glacier Cream), subsequently became the basis for the company Piz Buin, named in honor of the mountain where Greiter allegedly received the sunburn.


title: Sunscreen

text: In 1974, Greiter adapted earlier calculations from Friedrich Ellinger and Rudolf Schulze and introduced the "sun protection factor" (SPF), which has become the global standard for measuring UVB protection. It has been estimated that "Gletscher Crème" had an SPF of 2.


title: Sunscreen

text: Water-resistant sunscreens were introduced in 1977, and recent development efforts have focused on overcoming later concerns by making sunscreen protection both longer-lasting and broader-spectrum, as well as more appealing to use.


title: Sunscreen

text: New products are in development such as sunscreens based on bioadhesive nanoparticles. These function by encapsulating commercially used UV filters, while being not only adherent to the skin but also non-penetrant. This strategy inhibits primary UV-induced damage as well as secondary free radicals. Additionally, UV rays can pass through glass windows. Therefore it may be wise to wear sunscreen inside homes and cars.


title: Research stations in Antarctica

text: Multiple governments have set up permanent research stations in Antarctica and these bases are widely distributed. Unlike the drifting ice stations set up in the Arctic, the research stations of the Antarctic are constructed either on rock or on ice that is (for practical purposes) fixed in place.


title: Research stations in Antarctica

text: Many of the stations are staffed throughout the year. A total of 42 countries (as of October 2006), all signatories to the Antarctic Treaty, operate seasonal (summer) and year-round research stations on the continent. The population of people performing and supporting scientific research on the continent and nearby islands varies from approximately 4,000 during the summer season to 1,000 during winter (June). In addition to these permanent stations, approximately 30 field camps are established each summer to support specific projects.


title: Research stations in Antarctica

text: During the Heroic Age of Antarctic Exploration in the late 19th century, the first bases on the continent were established. In 1898, Carsten Borchgrevink, a Norwegian/British explorer, led the British Antarctic Expedition to Cape Adare, where he established the first Antarctic base on Ridley Beach. This expedition is often referred to now as the "Southern Cross" Expedition, after the expedition's ship name. Most of the staff were Norwegian, but the funds for the expedition were British, provided by Sir George Newnes. The 10 members of the expedition explored Robertson Bay to the west of Cape Adare by dog teams, and later, after being picked up by the ship at the base, went ashore on the Ross Ice Shelf for brief journeys. The expedition hut is still in good condition and visited frequently by tourists.


title: Research stations in Antarctica

text: The hut was later occupied by Scott's Northern Party under the command of Victor Campbell for a year in 1911, after its attempt to explore the eastern end of the ice shelf discovered Roald Amundsen already ashore preparing for his assault on the South Pole.


title: Research stations in Antarctica

text: In 1903, Dr William S. Bruce's Scottish National Antarctic Expedition set off to Antarctica, with one of its aims to establish a meteorological station in the area. After the expedition failed to find land, Bruce decided to head back to the Laurie Island in the South Orkneys and find an anchorage there. The islands were well-situated as a site for a meteorological station, and their relative proximity to the South American mainland allowed a permanent station to be established. Bruce instituted a comprehensive programme of work, involving meteorological readings, trawling for marine samples, botanical excursions, and the collection of biological and geological specimens.


title: Research stations in Antarctica

text: The major task completed during this time was the construction of a stone building, christened "Omond House". This was to act as living accommodation for the parties that would remain on Laurie Island to operate the proposed meteorological laboratory. The building was constructed from local materials using the dry stone method, with a roof improvised from wood and canvas sheeting. The completed house was 20 feet by 20 feet square (6m × 6m), with two windows, fitted as quarters for six people. Rudmose Brown wrote: "Considering that we had no mortar and no masons' tools it is a wonderfully fine house and very lasting. I should think it will be standing a century hence ..."


title: Research stations in Antarctica

text: Bruce later offered to Argentina the transfer of the station and instruments on the condition that the government committed itself to the continuation of the scientific mission. Bruce informed the British officer William Haggard of his intentions in December 1903, and Haggard ratified the terms of Bruce's proposition.


title: Research stations in Antarctica

text: The "Scotia" sailed back for Laurie Island on 14 January 1904 carrying on board Argentinean officials from the Ministry of Agriculture, National Meteorological Office, Ministry of Livestock and National Postal and Telegraphs Office. In 1906, Argentina communicated to the international community the establishment of a permanent base on the South Orkney Islands.


title: Research stations in Antarctica

text: Little happened for the following forty years until the Second World War, when the British launched Operation Tabarin in 1943, to establish a presence on the continent. The chief reason was to establish solid British claims to various uninhabited islands and parts of Antarctica, reinforced by Argentine sympathies toward Germany.


title: Research stations in Antarctica

text: Prior to the start of the war, German aircraft had dropped markers with swastikas across Queen Maud Land in an attempt to create a territorial claim (New Swabia). Led by Lieutenant James Marr, the 14-strong team left the Falkland Islands in two ships, HMS "William Scoresby" (a minesweeping trawler) and "HMS Fitzroy", on Saturday January 29, 1944. Marr had accompanied the British explorer Sir Ernest Shackleton on his final Antarctic expedition in 1921–22.


title: Research stations in Antarctica

text: Bases were established during February near the abandoned Norwegian whaling station on Deception Island, where the Union Flag was hoisted in place of Argentine flags, and at Port Lockroy (on February 11) on the coast of Graham Land. A further base was founded at Hope Bay on February 13, 1945, after a failed attempt to unload stores on February 7, 1944. These bases were the first ever to be constructed on the mainland Antarctica.


title: Research stations in Antarctica

text: The United States starting under the leadership of Admiral Richard E. Byrd constructed a series of five bases near the Bay of Whales named Little America between 1929 and 1958. All of them have now drifted off to sea on icebergs.


title: Research stations in Antarctica

text: A massive expansion in international activity followed the war. Chile organized its First Chilean Antarctic Expedition in 1947–48. Among other accomplishments, it brought the Chilean president Gabriel González Videla to personally inaugurate one of its bases, thereby becoming the first head of state to set foot on the continent. Signy Research Station (UK) was established in 1947, Australia's Mawson Station in 1954, Dumont d'Urville Station was the first French station in 1956. In that same year, the United States built McMurdo Station and Amundsen–Scott South Pole Station, and the Soviet Union built Mirny Station.


title: Research stations in Antarctica

text: The United States maintains the southernmost base, Amundsen–Scott South Pole Station, and the largest base and research station in Antarctica, McMurdo Station. The second-southernmost base is the Chinese Kunlun Station at 80°25′02″S during the summer season, and the Russian Vostok Station at 78°27′50″S during the winter season.


title: Visage (video game)

text: Visage is a 2020 independent psychological horror video game developed and published by SadSquare Studio. Set in a strangely structured house with a somber history, players control Dwayne Anderson as he explores the backstories of the inhabitants that once lived there. The game is presented in first-person perspective, and a large portion of the house is accessible, although some areas require keys. Obstacles include avoiding the dark to reduce loss of sanity, though several tools can aid players through the dark.


title: Visage (video game)

text: Mainly inspired by the "Silent Hills" playable teaser, the game ran Kickstarter and Steam Greenlight campaigns. Various horror video games were cited as inspirations, several of which also drew comparisons with "Visage". It was later released for PC on October 30, 2020, and in 2021 on console platforms. The game saw praise for its psychological effectiveness, audiovisual design, and atmospheric tension, though it was criticized for its limited inventory, cumbersome gameplay, and bugs.


title: Visage (video game)

text: "Visage" has a similar setting and gameplay as its spiritual predecessor "P.T.". The game takes place in a large suburban home in the 1980s and utilizes a first-person-perspective. The player controls Dwayne Anderson, an inhabitant of the home who committed suicide after killing his wife and children. Dwayne is trapped inside the house and is tormented by supernatural entities. The objective of the game is to find a way out of the house and learn about the cause of all the paranormal activity.


title: Visage (video game)

text: The house is designed as a semi-open world, with large sections freely explorable to the player at all times and multiple pathways to reach each area. However, in order to fully explore the map, players will need to find keys to unlock each door first. The player must face several hazards while exploring. First, they will have avoid dark areas to manage their sanity. Sanity, like similar systems in games such as "," is decreased if Dwayne stays in the dark for too long.


title: Visage (video game)

text: Secondly, ghosts will create paranormal events by manipulating the house as the player explores. Examples include light bulbs breaking, doors slamming or opening, and electronic devices malfunctioning. Witnessing these events will cause Dwayne's sanity to fall. Lastly, Dwayne must avoid being caught by the various ghosts and demons that inhabit the home. Being caught by these ghosts and demons means instant death, so players must carefully maneuver through the house to avoid them. The lower Dwayne's sanity, the more severe each paranormal event becomes, up to the point that a ghost or demon will appear and attack the player.


title: Visage (video game)

text: Players can use lighters, pills, light bulbs, and candles to help them avoid these threats. Lighters allow the player to move through dark areas without a light, taking pills can recover sanity, light bulbs can be used to repair broken lights, and candles are a light source that ghosts cannot manipulate. There are various other items the player can find and use, like a camera or a sledgehammer.


title: Visage (video game)

text: Dwayne has a very limited inventory and can store only five of these items at a time, and hold two more in his hands. As a result, the player must explore the house very carefully to uncover the truth.


title: Visage (video game)

text: The fourth chapter of the game is divided into seven subchapters; in each subchapter, players must find VHS tapes scattered through the house, each labeled differently: Pride, Negligence, Indifference, Prison, Addiction, Greed and Affliction.


title: Visage (video game)

text: In 1985 at a suburban home, a man named Dwayne Anderson shoots and kills his wife and two children before committing suicide. Later, Dwayne is depicted waking up in a bloody, empty room. After exiting it, he hears a voicemail from neighbor Rose, who has not seen him out of his house in three weeks. He tries opening the front door but it is locked. Paranormal events begin occurring throughout the house, and Dwayne begins searching for a way out. In the process, he navigates through experiences, divided into three chapters, centering around the people who once lived there.


title: Visage (video game)

text: The first chapter is about Lucy, a little girl who in 1965 was befriended by a demon that communicated with her via television and radio. Over time, due to the demon's influence, Lucy's behavior became increasingly abnormal. One day, under the demon's direction, Lucy murdered her pet bird Peaco by biting its head off. Lucy's horrified parents took her to therapy; however the syringing only worsened Lucy's mental state. Further tormented by the demon, she locked herself in the bathroom and ripped off her jaw, subsequently dying from blood loss while her parents desperately bang on the door; the demon later unlocked it.


title: Visage (video game)

text: The second chapter revolves around Dolores and George, an elderly couple who had a baby. In 1962, Dolores was reported to exhibit symptoms of various mental disorders, such as Dolores hearing her own voice from the baby monitor reciting a numerical sequence—the key to her "inner house." George believed that the remedies given to Dolores were unhelpful, stressing him. As Dolores worsened, she became increasingly mistrustful and even hostile towards George, once attacking him believing he was poisoning her tea. Dolores eventually murdered George, stabbing him with seven knives and leaving his corpse in his study room. Later, Dolores hanged herself next to her crying baby's bassinet.


title: Visage (video game)

text: The third chapter features 28-year-old Rakan Al-Mutawa, who suffered from scopophobia and believed that someone is spying on and attempting to silence him. In 1970, he was attacked by a shadowy entity and used a firearm to defend himself, after which he is interred in a psychiatric hospital. Believing the hospital to be part of the conspiracy against him, Rakan wreaked havoc: threatening the staff, behaving violently, jumping from a window, sabotaging the building's electricity, and even killing a staff member with a crowbar. Doctors were often forced to sedate him when he acts out. In response, Rakan was isolated from all other patients and staff. Months later, doctors concluded that Rakan is recovering, and he was officially discharged. Sometime later, however, Rakan, now disabled, declared victory against the unnamed entity, before being locked and killed in a desolate cell by an unknown figure.


title: Visage (video game)

text: The final chapter observes Dwayne's past family, consisting of wife Claire, son John, and daughter Sarah. Dwayne, an alcoholic, distanced himself from them. When Claire discovered that Dwayne had been abusively consuming Chlorpromazine to relieve stress, she expressed concern, however through his present senses, Dwayne learns that Claire was a gold digger who wanted him dead by various suicide methods, all of which are the causes of death of the previous inhabitants in the house. This chapter also has a scene where Dwayne sits at a sofa drinking a "wonderful" alcoholic "poison", as the television plays a live video of a masked man angrily seeking to find Dwayne's true self. There is also a scene set in Hell: a tall and wide cave, where people make themselves suffer; the masked man claims that thanks to Dwayne, everyone in Hell "enjoys their newfound home." The chapter ends with revealing that Dwayne was a scientist who started working at a water treatment plant in Riversdale, Maryland in April 1952. There, Dwayne drops an apple to a well, which causes dead bodies to float. He faints and wakes up at his house.


title: Visage (video game)

text: The game has multiple endings. In the default ending, Dwayne wears a mask, and it is day. He enters a room behind a haphazardly painted wall, and teleports to a white screen with his family in the distance. The credits' background feature a heavenly rainforest.


title: Visage (video game)

text: In the alternate ending, named "The Void", Dwayne enters the room. Opening a secret door and going down a staircase, he reaches the room in the game's opening, with the revolver there. Dwayne shoots himself like he did in the opening. In a flash, he sees the location of one of the seven VHS tapes needed to collect to achieve the default ending. After collecting one, time repeats itself six times— at last, the revolver is empty. Dwayne wakes up in the well in Chapter 4, endless in all directions. If the player plays via Steam or console, they will receive the Void Trophy.


title: Visage (video game)

text: "Visage" started development in January 2015 and was announced in September. The game was successfully financed by a Kickstarter campaign running from January through March 2016. They set the goal to CAD 35,000. In October 2015, a Steam Greenlight campaign was launched, featuring a trailer embedded in the page.


title: Visage (video game)

text: In an interview with "IGN", the developer, SadSquare Studio, stated that the game is conceptualized to mainly utilize "the uncanny" to create a sense of dread and fear. It was inspired by "P.T."., the teaser for "Silent Hills"; graphics designer Jonathan Vallières stated that the project's cancellation motivated the creation of the game. Other inspirations include "The Conjuring", "Insidious", "Sinister", "", "Ring", "Kairo", and "Phantasmagoria".


title: Visage (video game)

text: The developers initially targeted the release date to be in January 2017, in both computers (PC) and virtual reality (VR). On September 25, 2018 the developers announced that a demo of Visage would be released on October 2, 2018. The demo version for "Visage" was released on Steam on October 2, 2018, and that it was planned for release on early 2019. After a long delay, on February 15, 2020, SadSquare Studio announced that "the main content of "Visage" is pretty much done", and that they were projecting for a fall 2020 release. It was released on October 30, 2020, amidst the COVID-19 pandemic. In addition to PC, it was also released on PlayStation 4 and Xbox One. It was later released an "Enhanced Edition" on Xbox Series X and Series S and PlayStation 5 on October 28, 2021.


title: Visage (video game)

text: "Visage" received "generally positive" reviews on PC, PlayStation 4, and Xbox One, according to review aggregator Metacritic. On OpenCritic, it received a "Strong" grade (78%), also aggregating its Xbox Series X, Series S, and PlayStation 5 reviews.


title: Visage (video game)

text: Many critics praised the game's atmosphere, which they described as a perfect execution of the psychological horror genre, providing viewers with a constant and gradual state of anxiety, with the paranormal moments appearing in the climax of that anxiety, not abusing the jump scare device which many horror works tend to do. Doug Mercer of "COGconnected" called the game traumatizing and "nightmare-inducing", which gave it a unique style of storytelling, and Daniel Tack of "Game Informer" wrote that the game may cause real-life anxiety while opening doors or descending stairs. Thus, critics expressed guarantee that horror fans will be satisfied with the game, and that players will be interested to replay it. Its inspiration from "P.T." is said to be apparent, with "Eurogamer Italy" calling it "the best "Silent Hill" emulator of the last decade." The atmosphere is also credited to the sound design and lighting. It was also credited to the music, with the music from Lucy's chapter deemed the best for its gradual rise in tension, creating a rare kind of unsettlement. Some critics said that many faint-hearted gamers might not enjoy the game, and the lack of instructions was criticized. Lynn called the survival part of the game "underdeveloped", though he noted that the psychological aspect is what matters.


title: Visage (video game)

text: "Visage" story saw mixed reviews. Mercer praised the psychological effectiveness with the player character's objective of not turning insane, though criticized the way the story ends despite being overshadowed by the atmosphere. Alan Strawbridge of "PlayStation Universe" deemed Lucy's chapter the best. Though subsequent chapters still maintain the same tension in unique ways and was praised for diversifying the scope of the game, the repetition of the same places within the house was criticized.


title: Visage (video game)

text: The controls and dynamics of "Visage" have been widely criticized. Many critics commented on the limited inventory, meaning one cannot store as much survival items as needed. The gameplay also allows two items to be held at respective hands, which is criticized as its complexity makes the gameplay laborious and cumbersome, though it was noted that the game employs a niche, patience-centric type of horror gameplay. Strawbridge complained that some of the PlayStation controls were difficult to reach, ruining the suspension of disbelief. The frustration of trying to retrieve important items as players struggle to survive saw polarizing opinions, though it was said to be not much a problem for the minimalistic game. Several critics noted that there are some technical problems, obvious due to it being produced independently. However, it was also noted that these bugs prevented retrieval of items at times, and the game would often confuse the player standing in a lit area as being in a dim one. The struggle of having to save manually has also been noted.


title: Space debris

text: Space debris (also known as space junk, space pollution, space waste, space trash, or space garbage) are defunct human-made objects in space—principally in Earth orbit—which no longer serve a useful function. These include derelict spacecraft—nonfunctional spacecraft and abandoned launch vehicle stages—mission-related debris, and particularly numerous in Earth orbit, fragmentation debris from the breakup of derelict rocket bodies and spacecraft. In addition to derelict human-made objects left in orbit, other examples of space debris include fragments from their disintegration, erosion and collisions or even paint flecks, solidified liquids expelled from spacecraft, and unburned particles from solid rocket motors. Space debris represents a risk to spacecraft.


title: Space debris

text: Space debris is typically a negative externality—it creates an external cost on others from the initial action to launch or use a spacecraft in near-Earth orbit—a cost that is typically not taken into account nor fully accounted for in the cost by the launcher or payload owner.


title: Space debris

text: The measurement, mitigation, and potential removal of debris are conducted by some participants in the space industry.


title: Space debris

text: , the US Space Surveillance Network reported 21,901 artificial objects in orbit above the Earth, including 4,450 operational satellites. However, these are just the objects large enough to be tracked. , more than 128 million pieces of debris smaller than , about 900,000 pieces of debris 1–10 cm, and around 34,000 of pieces larger than were estimated to be in orbit around the Earth. When the smallest objects of artificial space debris (paint flecks, solid rocket exhaust particles, etc.) are grouped with micrometeoroids, they are together sometimes referred to by space agencies as MMOD (Micrometeoroid and Orbital Debris). Collisions with debris have become a hazard to spacecraft; the smallest objects cause damage akin to sandblasting, especially to solar panels and optics like telescopes or star trackers that cannot easily be protected by a ballistic shield.


title: Space debris

text: Below Earth-altitude, pieces of debris are denser than meteoroids; most are dust from solid rocket motors, surface erosion debris like paint flakes, and frozen coolant from Soviet nuclear-powered satellites. For comparison, the International Space Station orbits in the range, while the two most recent large debris events—the 2007 Chinese antisat weapon test and the 2009 satellite collision—occurred at altitude. The ISS has Whipple shielding to resist damage from small MMOD; however, known debris with a collision chance over 1/10,000 are avoided by maneuvering the station.


title: Space debris

text: Space debris began to accumulate in Earth orbit immediately with the first launch of an artificial satellite Sputnik 1 into orbit in October 1957. But even before that, beside natural ejecta from Earth, humans might have produced ejecta that became space debris, as in the August 1957 Pascal B test. After the launch of Sputnik, the North American Aerospace Defense Command (NORAD) began compiling a database (the Space Object Catalog) of all known rocket launches and objects reaching orbit: satellites, protective shields and upper-stages of launch vehicles. NASA later published modified versions of the database in two-line element set, and beginning in the early 1980s the CelesTrak bulletin board system re-published them.


title: Space debris

text: The trackers (NORAD) who fed the database were aware of other objects in orbit, many of which were the result of in-orbit explosions. Some were deliberately caused during the 1960s anti-satellite weapon (ASAT) testing, and others were the result of rocket stages blowing up in orbit as leftover propellant expanded and ruptured their tanks. To improve tracking, NORAD employee John Gabbard kept a more detailed database of as many objects as he could identify.


title: Space debris

text: Studying the explosions, In March 1971, Gabbard developed a technique for predicting the orbital paths of their products, and Gabbard diagrams (or plots) are now widely used. These studies were used to improve the modeling of orbital evolution and decay.


title: Space debris

text: When the NORAD database became publicly available during the 1970s, techniques developed for the asteroid-belt were applied to the study to the database of known artificial satellite Earth objects.


title: Space debris

text: In addition to approaches to debris reduction where time and natural gravitational/atmospheric effects help to clear space debris, or a variety of technological approaches that have been proposed (with most not implemented) to reduce space debris, a number of scholars have observed that institutional factors—political, legal, economic and cultural "rules of the game"—are the greatest impediment to the cleanup of near-Earth space. By 2014, there was little commercial incentive to reduce space debris, since the cost of dealing with it is not assigned to the entity producing it, but rather falls on all users of the space environment, and rely on human society as a whole that benefits from space technologies and knowledge. A number of suggestions for improving institutions so as to increase the incentives to reduce space debris have been made. These include government mandates to create incentives, as well as companies coming to see economic benefit to reducing debris more aggressively than existing government standard practices.


title: Space debris

text: In 1979 NASA founded the Orbital Debris Program to research mitigation measures for space debris in Earth orbit.


title: Space debris

text: During the 1980s, NASA and other U.S. groups attempted to limit the growth of debris. One trial solution was implemented by McDonnell Douglas for the Delta launch vehicle, by having the booster move away from its payload and vent any propellant remaining in its tanks. This eliminated one source for pressure buildup in the tanks which had previously caused them to explode and create additional orbital debris. Other countries were slower to adopt this measure and, due especially to a number of launches by the Soviet Union, the problem grew throughout the decade.


title: Space debris

text: A new battery of studies followed as NASA, NORAD and others attempted to better understand the orbital environment, with each adjusting the number of pieces of debris in the critical-mass zone upward. Although in 1981 (when Schefter's article was published) the number of objects was estimated at 5,000, new detectors in the Ground-based Electro-Optical Deep Space Surveillance system found new objects. By the late 1990s, it was thought that most of the 28,000 launched objects had already decayed and about 8,500 remained in orbit. By 2005 this was adjusted upward to 13,000 objects, and a 2006 study increased the number to 19,000 as a result of an ASAT test and a satellite collision. In 2011, NASA said that 22,000 objects were being tracked.


title: Space debris

text: A 2006 NASA model suggested that if no new launches took place the environment would retain the then-known population until about 2055, when it would increase on its own. Richard Crowther of Britain's Defence Evaluation and Research Agency said in 2002 that he believed the cascade would begin about 2015. The National Academy of Sciences, summarizing the professional view, noted widespread agreement that two bands of LEO space—900 to and —were already past critical density.


title: Space debris

text: In the 2009 European Air and Space Conference, University of Southampton researcher Hugh Lewis predicted that the threat from space debris would rise 50 percent in the next decade and quadruple in the next 50 years. , more than 13,000 close calls were tracked weekly.


title: Space debris

text: A 2011 report by the U.S. National Research Council warned NASA that the amount of orbiting space debris was at a critical level. According to some computer models, the amount of space debris "has reached a tipping point, with enough currently in orbit to continually collide and create even more debris, raising the risk of spacecraft failures". The report called for international regulations limiting debris and research of disposal methods.


title: Space debris

text: There are estimated to be over 128 million pieces of debris smaller than as of January 2019. There are approximately 900,000 pieces from 1 to 10 cm. The current count of large debris (defined as 10 cm across or larger) is 34,000. The technical measurement cutoff is c. . As of 2020 there is 8,000 metric tons of debris in orbit with no signs of slowing down.


title: Space debris

text: In the orbits nearest to Earth—less than orbital altitude, referred to as low-Earth orbit (LEO)—there have traditionally been few "universal orbits" that keep a number of spacecraft in particular rings (in contrast to GEO, a single orbit that is widely used by over 500 satellites). This is beginning to change in 2019, and several companies have begun to deploy the early phases of satellite internet constellations, which will have many universal orbits in LEO with 30 to 50 satellites per orbital plane and altitude. Traditionally, the most populated LEO orbits have been a number of sun-synchronous satellites that keep a constant angle between the Sun and the orbital plane, making Earth observation easier with consistent sun angle and lighting. Sun-synchronous orbits are polar, meaning they cross over the polar regions. LEO satellites orbit in many planes, typically up to 15 times a day, causing frequent approaches between objects. The density of satellites—both active and derelict—is much higher in LEO.


title: Space debris

text: Orbits are affected by gravitational perturbations (which in LEO include unevenness of the Earth's gravitational field due to variations in the density of the planet), and collisions can occur from any direction. The average impact speed of collisions in Low Earth Orbit is 10 km/s with maximums reaching above 14 km/s due to orbital eccentricity. The 2009 satellite collision occurred at a closing speed of , creating over 2,000 large debris fragments. These debris cross many other orbits and increase debris collision risk.


title: Space debris

text: It is theorized that a sufficiently large collision of spacecraft could potentially lead to a cascade effect, or even make some particular low Earth orbits effectively unusable for long term use by orbiting satellites, a phenomenon known as the Kessler syndrome. The theoretical effect is projected to be a theoretical runaway chain reaction of collisions that could occur, exponentially increasing the number and density of space debris in low-Earth orbit, and has been hypothesized to ensue beyond some critical density.


title: Space debris

text: Crewed space missions are mostly at altitude and below, where air drag helps clear zones of fragments. The upper atmosphere is not a fixed density at any particular orbital altitude; it varies as a result of atmospheric tides and expands or contracts over longer time periods as a result of space weather. These longer-term effects can increase drag at lower altitudes; the 1990s expansion was a factor in reduced debris density. Another factor was fewer launches by Russia; the Soviet Union made most of their launches in the 1970s and 1980s.


title: Space debris

text: At higher altitudes, where air drag is less significant, orbital decay takes longer. Slight atmospheric drag, lunar perturbations, Earth's gravity perturbations, solar wind and solar radiation pressure can gradually bring debris down to lower altitudes (where it decays), but at very high altitudes this may take millennia. Although high-altitude orbits are less commonly used than LEO and the onset of the problem is slower, the numbers progress toward the critical threshold more quickly.


title: Space debris

text: Many communications satellites are in geostationary orbits (GEO), clustering over specific targets and sharing the same orbital path. Although velocities are low between GEO objects, when a satellite becomes derelict (such as Telstar 401) it assumes a geosynchronous orbit; its orbital inclination increases about .8° and its speed increases about per year. Impact velocity peaks at about . Orbital perturbations cause longitude drift of the inoperable spacecraft and precession of the orbital plane. Close approaches (within 50 meters) are estimated at one per year. The collision debris pose less short-term risk than from an LEO collision, but the satellite would likely become inoperable. Large objects, such as solar-power satellites, are especially vulnerable to collisions.


title: Space debris

text: Although the ITU now requires proof a satellite can be moved out of its orbital slot at the end of its lifespan, studies suggest this is insufficient. Since GEO orbit is too distant to accurately measure objects under , the nature of the problem is not well known. Satellites could be moved to empty spots in GEO, requiring less maneuvering and making it easier to predict future motion. Satellites or boosters in other orbits, especially stranded in geostationary transfer orbit, are an additional concern due to their typically high crossing velocity.


title: Space debris

text: Despite efforts to reduce risk, spacecraft collisions have occurred. The European Space Agency telecom satellite Olympus-1 was struck by a meteoroid on 11 August 1993 and eventually moved to a graveyard orbit. On 29 March 2006, the Russian Express-AM11 communications satellite was struck by an unknown object and rendered inoperable; its engineers had enough contact time with the satellite to send it into a graveyard orbit.


title: Space debris

text: In 1958, the United States launched Vanguard I into a medium Earth orbit (MEO). , it, and the upper stage of its launch rocket, were the oldest surviving artificial space objects still in orbit. In a catalog of known launches until July 2009, the Union of Concerned Scientists listed 902 operational satellites from a known population of 19,000 large objects and about 30,000 objects launched.


title: Space debris

text: An example of additional derelict satellite debris is the remains of the 1970s/80s Soviet RORSAT naval surveillance satellite program. The satellites' BES-5 nuclear reactors were cooled with a coolant loop of sodium-potassium alloy, creating a potential problem when the satellite reached end of life. While many satellites were nominally boosted into medium-altitude graveyard orbits, not all were. Even satellites that had been properly moved to a higher orbit had an eight-percent probability of puncture and coolant release over a 50-year period. The coolant freezes into droplets of solid sodium-potassium alloy, forming additional debris.


title: Space debris

text: In February 2015, the USAF Defense Meteorological Satellite Program Flight 13 (DMSP-F13) exploded on orbit, creating at least 149 debris objects, which were expected to remain in orbit for decades.


title: Space debris

text: Orbiting satellites have been deliberately destroyed. United States and USSR/Russia have conducted over 30 and 27 ASAT tests, respectively, followed by 10 from China and one from India. The most recent ASATs were Chinese interception of FY-1C, trials of Russian PL-19 Nudol, American interception of USA-193 and Indian interception of unstated live satellite.


title: Space debris

text: Space debris includes a glove lost by astronaut Ed White on the first American space-walk (EVA), a camera lost by Michael Collins near Gemini 10, a thermal blanket lost during STS-88, garbage bags jettisoned by Soviet cosmonauts during Mir's 15-year life, a wrench, and a toothbrush. Sunita Williams of STS-116 lost a camera during an EVA. During an STS-120 EVA to reinforce a torn solar panel, a pair of pliers was lost, and in an STS-126 EVA, Heidemarie Stefanyshyn-Piper lost a briefcase-sized tool bag.


title: Space debris

text: In characterizing the problem of space debris, it was learned that much debris was due to rocket upper stages (e.g. the Inertial Upper Stage) which end up in orbit, and break up due to decomposition of unvented unburned fuel. However, a major known impact event involved an (intact) Ariane booster. Although NASA and the United States Air Force now require upper-stage passivation, other launchers do not. Lower stages, like the Space Shuttle's solid rocket boosters or Apollo program's Saturn IB launch vehicles, do not reach orbit.


title: Space debris

text: On 11 March 2000 a Chinese Long March 4 CBERS-1 upper stage exploded in orbit, creating a debris cloud. A Russian Briz-M booster stage exploded in orbit over South Australia on 19 February 2007. Launched on 28 February 2006 carrying an Arabsat-4A communications satellite, it malfunctioned before it could use up its propellant. Although the explosion was captured on film by astronomers, due to the orbit path the debris cloud has been difficult to measure with radar. By 21 February 2007, over 1,000 fragments were identified. A 14 February 2007 breakup was recorded by Celestrak. Eight breakups occurred in 2006, the most since 1993. Another Briz-M broke up on 16 October 2012 after a failed 6 August Proton-M launch. The amount and size of the debris was unknown. A Long March 7 rocket booster created a fireball visible from portions of Utah, Nevada, Colorado, Idaho and California on the evening of 27 July 2016; its disintegration was widely reported on social media. In 2018–2019, three different Atlas V Centaur second stages have broken up.


title: Space debris

text: In December 2020, scientists confirmed that a previously detected near-Earth object, 2020 SO, was rocket booster space junk launched in 1966 orbiting Earth and the Sun.


title: Space debris

text: A past debris source was the testing of anti-satellite weapons (ASATs) by the U.S. and Soviet Union during the 1960s and 1970s. North American Aerospace Defense Command (NORAD) files only contained data for Soviet tests, and debris from U.S. tests were only identified later. By the time the debris problem was understood, widespread ASAT testing had ended; the U.S. Program 437 was shut down in 1975.


title: Space debris

text: The U.S. restarted their ASAT programs in the 1980s with the Vought ASM-135 ASAT. A 1985 test destroyed a satellite orbiting at , creating thousands of debris larger than . Due to the altitude, atmospheric drag decayed the orbit of most debris within a decade. A "de facto" moratorium followed the test.


title: Space debris

text: China's government was condemned for the military implications and the amount of debris from the 2007 anti-satellite missile test, the largest single space debris incident in history (creating over 2,300 pieces golf-ball size or larger, over 35,000 or larger, and one million pieces or larger). The target satellite orbited between and , the portion of near-Earth space most densely populated with satellites. Since atmospheric drag is low at that altitude, the debris is slow to return to Earth, and in June 2007 NASA's Terra environmental spacecraft maneuvered to avoid impact from the debris. Dr. Brian Weeden, U.S. Air Force officer and Secure World Foundation staff member, noted that the 2007 Chinese satellite explosion created an orbital debris of more than 3,000 separate objects that then required tracking.


title: Space debris

text: On 20 February 2008, the U.S. launched an SM-3 missile from the USS "Lake Erie" to destroy a defective U.S. spy satellite thought to be carrying of toxic hydrazine propellant. The event occurred at about , and the resulting debris has a perigee of or lower. The missile was aimed to minimize the amount of debris, which (according to Pentagon Strategic Command chief Kevin Chilton) had decayed by early 2009.


title: Space debris

text: On 27 March 2019, Indian Prime Minister Narendra Modi announced that India shot down one of its own LEO satellites with a ground-based missile. He stated that the operation, part of "Mission Shakti", would defend the country's interests in space. Afterwards, US Air Force Space Command announced they were tracking 270 new pieces of debris but expected the number to grow as data collection continues.


title: Space debris

text: On 15 November 2021 the Russian Defense Ministry destroyed Kosmos 1408 orbiting at around 450 km, creating "more than 1,500 pieces of trackable debris and hundreds of thousands of pieces of un-trackable debris" according to the US State Department.


title: Space debris

text: The vulnerability of satellites to debris and the possibility of attacking LEO satellites to create debris clouds has triggered speculation that it is possible for countries unable to make a precision attack. An attack on a satellite of or more would heavily damage the LEO environment.


title: Space debris

text: Space junk can be a hazard to active satellites and spacecraft. It has been theorized that Earth orbit could even become impassable if the risk of collision grows too high.


title: Space debris

text: However, since the risk to spacecraft increases with the time of exposure to high debris densities, it is more accurate to say that LEO would be rendered "unusable" by orbiting craft. The threat to craft "passing through" LEO to reach higher orbit would be much lower owing to the very short time span of the crossing.


title: Space debris

text: Although spacecraft are typically protected by Whipple shields, solar panels, which are exposed to the Sun, wear from low-mass impacts. Even small impacts can produce a cloud of plasma which is an electrical risk to the panels.


title: Space debris

text: Satellites are believed to have been destroyed by micrometeorites and (small) orbital debris (MMOD). The earliest suspected loss was of Kosmos 1275, which disappeared on 24 July 1981 (a month after launch). Kosmos contained no volatile propellant, therefore, there appeared to be nothing internal to the satellite which could have caused the destructive explosion which took place. However, the case has not been proven and another hypothesis forwarded is that the battery exploded. Tracking showed it broke up, into 300 new objects.


title: Space debris

text: Many impacts have been confirmed since. For example, on 24 July 1996, the French microsatellite Cerise was hit by fragments of an Ariane-1 H-10 upper-stage booster which exploded in November 1986. On 29 March 2006, the Russian Ekspress AM11 communications satellite was struck by an unknown object and rendered inoperable. On 13 October 2009, Terra suffered a single battery cell failure anomaly and a battery heater control anomaly which were subsequently considered likely the result of an MMOD strike. On 12 March 2010, Aura lost power from one-half of one of its 11 solar panels and this was also attributed to an MMOD strike. On 22 May 2013, GOES 13 was hit by an MMOD which caused it to lose track of the stars that it used to maintain an operational attitude. It took nearly a month for the spacecraft to return to operation.


title: Space debris

text: The first major satellite collision occurred on 10 February 2009. The derelict satellite Kosmos 2251 and the operational Iridium 33 collided, over northern Siberia. The relative speed of impact was about , or about . Both satellites were destroyed, creating thousands of pieces of new smaller debris, with legal and political liability issues unresolved even years later. On 22 January 2013, BLITS (a Russian laser-ranging satellite) was struck by debris suspected to be from the 2007 Chinese anti-satellite missile test, changing both its orbit and rotation rate.


title: Space debris

text: Satellites sometimes perform Collision Avoidance Maneuvers and satellite operators may monitor space debris as part of maneuver planning. For example, in January 2017, the European Space Agency made the decision to alter orbit of one of its three Swarm mission spacecraft, based on data from the US Joint Space Operations Center, to lower the risk of collision from Cosmos-375, a derelict Russian satellite.


title: Space debris

text: Crewed flights are naturally particularly sensitive to the hazards that could be presented by space debris conjunctions in the orbital path of the spacecraft. Examples of occasional avoidance maneuvers, or longer-term space debris wear, have occurred in Space Shuttle missions, the MIR space station, and the International Space Station.


title: Space debris

text: From the early Space Shuttle missions, NASA used NORAD space monitoring capabilities to assess the Shuttle's orbital path for debris. In the 1980s, this used a large proportion of NORAD capacity. The first collision-avoidance maneuver occurred during STS-48 in September 1991, a seven-second thruster burn to avoid debris from the derelict satellite Kosmos 955. Similar maneuvers were initiated on missions 53, 72 and 82.


title: Space debris

text: One of the earliest events to publicize the debris problem occurred on 's second flight, STS-7. A fleck of paint struck its front window, creating a pit over wide. On STS-59 in 1994, "Endeavour"'s front window was pitted about half its depth. Minor debris impacts increased from 1998.


title: Space debris

text: Window chipping and minor damage to thermal protection system tiles (TPS) were already common by the 1990s. The Shuttle was later flown tail-first to take a greater proportion of the debris load on the engines and rear cargo bay, which are not used in orbit or during descent, and thus are less critical for post-launch operation. When flying attached to the ISS, the two connected spacecraft were flipped around so the better-armored station shielded the orbiter.


title: Space debris

text: A NASA 2005 study concluded that debris accounted for approximately half of the overall risk to the Shuttle. Executive-level decision to proceed was required if catastrophic impact was likelier than 1 in 200. On a normal (low-orbit) mission to the ISS the risk was approximately 1 in 300, but the Hubble telescope repair mission was flown at the higher orbital altitude of where the risk was initially calculated at a 1-in-185 (due in part to the 2009 satellite collision). A re-analysis with better debris numbers reduced the estimated risk to 1 in 221, and the mission went ahead.


title: Space debris

text: Debris incidents continued on later Shuttle missions. During STS-115 in 2006 a fragment of circuit board bored a small hole through the radiator panels in "Atlantis"s cargo bay. On STS-118 in 2007 debris blew a bullet-like hole through "Endeavour"s radiator panel.


title: Space debris

text: Impact wear was notable on "Mir", the Soviet space station, since it remained in space for long periods with its original solar module panels.


title: Space debris

text: The ISS also uses Whipple shielding to protect its interior from minor debris. However, exterior portions (notably its solar panels) cannot be protected easily. In 1989, the ISS panels were predicted to degrade approximately 0.23% in four years due to the "sandblasting" effect of impacts with small orbital debris. An avoidance maneuver is typically performed for the ISS if "there is a greater than one-in-10,000 chance of a debris strike". , there have been sixteen maneuvers in the fifteen years the ISS had been in orbit. By 2019, over 1,400 meteoroid and orbital debris (MMOD) impacts had been recorded on the ISS.


title: Space debris

text: As another method to reduce the risk to humans on board, ISS operational management asked the crew to shelter in the Soyuz on three occasions due to late debris-proximity warnings. In addition to the sixteen thruster firings and three Soyuz-capsule shelter orders, one attempted maneuver was not completed due to not having the several days' warning necessary to upload the maneuver timeline to the station's computer. A March 2009 event involved debris believed to be a piece of the Kosmos 1275 satellite. In 2013, the ISS operations management did not make a maneuver to avoid any debris, after making a record four debris maneuvers the previous year.


title: Space debris

text: The Kessler syndrome, proposed by NASA scientist Donald J. Kessler in 1978, is a theoretical scenario in which the density of objects in low Earth orbit (LEO) is high enough that collisions between objects could cause a cascade effect where each collision generates space debris that increases the likelihood of further collisions. He further theorized that one implication if this were to occur is that the distribution of debris in orbit could render space activities and the use of satellites in specific orbital ranges economically impractical for many generations.


title: Space debris

text: The growth in the number of objects as a result of the late-1990s studies sparked debate in the space community on the nature of the problem and the earlier dire warnings. According to Kessler's 1991 derivation and 2001 updates, the LEO environment in the altitude range should be cascading. However, only one major satellite collision incident has occurred: the 2009 satellite collision between Iridium 33 and Cosmos 2251. The lack of obvious short-term cascading has led to speculation that the original estimates overstated the problem. According to Kessler in 2010 however, a cascade may not be obvious until it is well advanced, which might take years.


title: Space debris

text: Although most debris burns up in the atmosphere, larger debris objects can reach the ground intact. According to NASA, an average of one cataloged piece of debris has fallen back to Earth each day for the past 50 years. Despite their size, there has been no significant property damage from the debris. Burning up in the atmosphere may also contribute to atmospheric pollution. Numerous small cylindrical tanks from space objects have been found, designed to hold fuel or gasses.


title: Space debris

text: Radar and optical detectors such as lidar are the main tools for tracking space debris. Although objects under have reduced orbital stability, debris as small as 1 cm can be tracked, however determining orbits to allow re-acquisition is difficult. Most debris remain unobserved. The NASA Orbital Debris Observatory tracked space debris with a liquid mirror transit telescope. FM Radio waves can detect debris, after reflecting off them onto a receiver. Optical tracking may be a useful early-warning system on spacecraft.


title: Space debris

text: The U.S. Strategic Command keeps a catalog of known orbital objects, using ground-based radar and telescopes, and a space-based telescope (originally to distinguish from hostile missiles). The 2009 edition listed about 19,000 objects. Other data come from the ESA Space Debris Telescope, TIRA, the Goldstone, Haystack, and EISCAT radars and the Cobra Dane phased array radar, to be used in debris-environment models like the ESA Meteoroid and Space Debris Terrestrial Environment Reference (MASTER).