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145-420: The location is near ideal because of its dark skies from lack of light pollution, good astronomical seeing , low humidity , high elevation of 4,205 meters (13,796 ft), position above most of the water vapor in the atmosphere, clean air, good weather and low latitude location. Significantly predating the current observatories there is evidence of active astronomy on Mauna Kea in the 1901 Land Office Map of

290-580: A spectral resolution of 90,000. Also optimized for ultraviolet observations were the FOC and FOS, which were capable of the highest spatial resolution of any instruments on Hubble. Rather than CCDs, these three instruments used photon -counting digicons as their detectors. The FOC was constructed by ESA, while the University of California, San Diego , and Martin Marietta Corporation built

435-732: A 25 MHz Intel-based 80486 processor system during Servicing Mission 3A in 1999. The new computer is 20 times faster, with six times more memory, than the DF-224 it replaced. It increases throughput by moving some computing tasks from the ground to the spacecraft and saves money by allowing the use of modern programming languages. Additionally, some of the science instruments and components had their own embedded microprocessor-based control systems. The MATs (Multiple Access Transponder) components, MAT-1 and MAT-2, use Hughes Aircraft CDP1802CD microprocessors. The Wide Field and Planetary Camera (WFPC) also used an RCA 1802 microprocessor (or possibly

580-488: A back-up mirror using traditional mirror-polishing techniques. (The team of Kodak and Itek also bid on the original mirror polishing work. Their bid called for the two companies to double-check each other's work, which would have almost certainly caught the polishing error that later caused problems .) The Kodak mirror is now on permanent display at the National Air and Space Museum . An Itek mirror built as part of

725-419: A different point from the light reflecting off its center. The effect of the mirror flaw on scientific observations depended on the particular observation—the core of the aberrated PSF was sharp enough to permit high-resolution observations of bright objects, and spectroscopy of point sources was affected only through a sensitivity loss. However, the loss of light to the large, out-of-focus halo severely reduced

870-432: A dirt road to the summit where he built a small telescope on Puʻu Poliʻahu, a cinder cone peak. The peak was the second highest on the mountain with the highest peak being holy ground, so Kuiper avoided it. Next, Kuiper tried enlisting NASA to fund a larger facility with a large telescope, housing and other needed structures. NASA, in turn, decided to make the project open to competition. Professor of physics, John Jefferies of

1015-596: A factor for consideration. The altitude and isolation in the middle of the Pacific Ocean makes Mauna Kea one of the best locations on Earth for ground-based astronomy. It is an ideal location for submillimeter, infrared and optical observations. The seeing statistics show that Mauna Kea is the best site in terms of optical and infrared image quality; for example, the CFHT site has a median seeing of 0.43 arcseconds. Accommodations for research astronomers are located at

1160-586: A father of modern rocketry, along with Robert H. Goddard and Konstantin Tsiolkovsky —published Die Rakete zu den Planetenräumen ("The Rocket into Planetary Space"), which mentioned how a telescope could be propelled into Earth orbit by a rocket. The history of the Hubble Space Telescope can be traced to 1946, to astronomer Lyman Spitzer 's paper "Astronomical advantages of an extraterrestrial observatory". In it, he discussed

1305-437: A final sharp focus and the best image quality obtained was drastically lower than expected. Images of point sources spread out over a radius of more than one arcsecond, instead of having a point spread function (PSF) concentrated within a circle 0.1  arcseconds (485 n rad ) in diameter, as had been specified in the design criteria. Analysis of the flawed images revealed that the primary mirror had been polished to

1450-546: A full-up start. There was some opposition on [Capitol] Hill to getting a new start on [Hubble]. It was driven, in large part as I recall, by the budget situation. Jim Fletcher proposed that we put in $ 5 million as a placeholder. I didn't like that idea. It was, in today's vernacular, a "sop" to the astronomy community. "There's something in there, so all is well". I figured in my own little head that to get that community energized we'd be better off zeroing it out. Then they would say, "Whoa, we're in deep trouble", and it would marshal

1595-818: A light cloud above the land, the excess light disrupts the clear pictures taken by the telescopes. On July 1, 2013, the Hawaii Night Sky Protection Act was initiated, affecting both the Big Island and Maui. A large difference between the Hawaiian islands and the mainland United States can be observed: street lighting. Almost all streets are dark as the lamps have either not been built, have been removed, or have been dimmed. The Mauna Kea Observatories involves thirteen large telescopes. In November 2020, in collaboration with Europe's low-frequency ARray radio telescope, Mauna Kea's Gemini observatory and

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1740-584: A mechanism for processing citizen inquiries and complaints. The U.S. Green Building Council (USGBC) has also incorporated a credit for reducing the amount of light trespass and sky glow into their environmentally friendly building standard known as LEED . Light trespass can be reduced by selecting light fixtures that limit the amount of light emitted more than 80° above the nadir. The IESNA definitions include full cutoff (0%), cutoff (10%), and semi-cutoff (20%). (These definitions also include limits on light emitted above 90° to reduce sky glow.) Over-illumination

1885-567: A meeting in 2009 on Circadian Disruption and Cancer. In different wavelengths of light, red light has the least inhibitory effect on melatonin. In June 2009, the American Medical Association developed a policy in support of control of light pollution. News about the decision emphasized glare as a public health hazard leading to unsafe driving conditions. Especially in the elderly, glare produces loss of contrast, obscuring night vision. A new 2021 study published in

2030-461: A nationwide lobbying effort was coordinated among astronomers. Many astronomers met congressmen and senators in person, and large-scale letter-writing campaigns were organized. The National Academy of Sciences published a report emphasizing the need for a space telescope, and eventually, the Senate agreed to half the budget that had originally been approved by Congress. The funding issues led to

2175-554: A possibly failure-prone battery, and make other improvements. Furthermore, the ground software needed to control Hubble was not ready in 1986, and was barely ready by the 1990 launch. Following the resumption of shuttle flights, Space Shuttle Discovery successfully launched the Hubble on April 24, 1990, as part of the STS-31 mission. At launch, NASA had spent approximately US$ 4.7 billion in inflation-adjusted 2010 dollars on

2320-449: A project of this importance, as their budget and timescale for producing the rest of the OTA continued to inflate. In response to a schedule described as "unsettled and changing daily", NASA postponed the launch date of the telescope until April 1985. Perkin-Elmer's schedules continued to slip at a rate of about one month per quarter, and at times delays reached one day for each day of work. NASA

2465-551: A reduction in the scale of the project, with the proposed mirror diameter reduced from 3 m to 2.4 m, both to cut costs and to allow a more compact and effective configuration for the telescope hardware. A proposed precursor 1.5 m (4 ft 11 in) space telescope to test the systems to be used on the main satellite was dropped, and budgetary concerns also prompted collaboration with the European Space Agency (ESA). ESA agreed to provide funding and supply one of

2610-565: A resolution of 0.64 megapixels. The wide field camera (WFC) covered a large angular field at the expense of resolution, while the planetary camera (PC) took images at a longer effective focal length than the WF chips, giving it a greater magnification. The Goddard High Resolution Spectrograph (GHRS) was a spectrograph designed to operate in the ultraviolet. It was built by the Goddard Space Flight Center and could achieve

2755-507: A space-based reflecting telescope with a mirror 3 m (9.8 ft) in diameter, known provisionally as the Large Orbiting Telescope or Large Space Telescope (LST), with a launch slated for 1979. These plans emphasized the need for crewed maintenance missions to the telescope to ensure such a costly program had a lengthy working life, and the concurrent development of plans for the reusable Space Shuttle indicated that

2900-478: A tenth of the wavelength of visible light , but the Space Telescope was to be used for observations from the visible through the ultraviolet (shorter wavelengths) and was specified to be diffraction limited to take full advantage of the space environment. Therefore, its mirror needed to be polished to an accuracy of 10 nanometers, or about 1/65 of the wavelength of red light. On the long wavelength end,

3045-403: A theoretical diffraction-limited resolution of about 0.05 arcsec for an optical telescope with a mirror 2.5 m (8 ft 2 in) in diameter. Second, a space-based telescope could observe infrared and ultraviolet light, which are strongly absorbed by the atmosphere of Earth . Spitzer devoted much of his career to pushing for the development of a space telescope. In 1962, a report by

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3190-732: A very small scale following World War II , as scientists made use of developments that had taken place in rocket technology. The first ultraviolet spectrum of the Sun was obtained in 1946, and NASA launched the Orbiting Solar Observatory (OSO) to obtain UV, X-ray, and gamma-ray spectra in 1962. An orbiting solar telescope was launched in 1962 by the United Kingdom as part of the Ariel programme , and in 1966 NASA launched

3335-406: A way that is not accurately predictable. The density of the upper atmosphere varies according to many factors, and this means Hubble's predicted position for six weeks' time could be in error by up to 4,000 km (2,500 mi). Observation schedules are typically finalized only a few days in advance, as a longer lead time would mean there was a chance the target would be unobservable by the time it

3480-446: Is a hormone that regulates photoperiodic physiology and behaviour. Some species of frogs and salamanders utilize a light-dependent "compass" to orient their migratory behaviour to breeding sites. Introduced light can also cause developmental irregularities, such as retinal damage, reduced juvenile growth, premature metamorphosis, reduced sperm production, and genetic mutation. Close to global coastal megacities (e.g. Tokyo, Shanghai),

3625-528: Is a nine-level measuring system used to track how much light pollution there is in the sky. A Bortle scale of four or less is required to see the Milky Way whilst one is "pristine", the darkest possible. Inspection of the area surrounding Madrid reveals that the effects of light pollution caused by a single large conglomeration can be felt up to 100 km (62 mi) away from the center. Global effects of light pollution are also made obvious. Research in

3770-418: Is a public-health hazard—especially the older you become. Glare light scattering in the eye causes loss of contrast and leads to unsafe driving conditions, much like the glare on a dirty windshield from low-angle sunlight or the high beams from an oncoming car." In essence bright and/or badly shielded lights around roads can partially blind drivers or pedestrians and contribute to accidents. The blinding effect

3915-592: Is also used to refer to artificial light indoors. Adverse consequences are multiple; some of them may not be known yet. Light pollution competes with starlight in the night sky for urban residents, interferes with astronomical observatories , and, like any other form of pollution , disrupts ecosystems and has adverse health effects. Light pollution is a side-effect of industrial civilization. Its sources include building exterior and interior lighting, advertising, outdoor area lighting (such as car parks), offices, factories, streetlights, and illuminated sporting venues. It

4060-449: Is caused by inefficient or unnecessary use of artificial light. Specific categories of light pollution include light trespass, over-illumination, glare, light clutter, and skyglow. A single offending light source often falls into more than one of these categories. Solutions to light pollution are often easy steps like adjusting light fixtures or using more appropriate light bulbs. Further remediation can be done with more efforts to educate

4205-417: Is caused in large part by reduced contrast due to light scattering in the eye by excessive brightness, or to the reflection of light from dark areas in the field of vision, with luminance similar to the background luminance. This kind of glare is a particular instance of disability glare, called veiling glare. (This is not the same as loss of accommodation of night vision which is caused by the direct effect of

4350-466: Is leased by the State of Hawaiʻi's Department of Land and Natural Resources (DLNR). The University of Hawaiʻi manages the site and leases land to several multi-national facilities, which have invested more than $ 2 billion in science and technology. The lease expires in 2033 and after that 40 of 45 square kilometers (25 of 28 square miles) revert to the state of Hawaii. Currently, pressure has been placed on

4495-475: Is most severe in highly industrialized, densely populated areas of North America, Europe, and Asia and in major cities in the Middle East and North Africa like Tehran and Cairo , but even relatively small amounts of light can be noticed and create problems. Awareness of the harmful effects of light pollution began in the second half of the 19th century, but efforts to address its effects did not begin until

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4640-400: Is natural. To precisely measure how bright the sky gets, night time satellite imagery of the earth is used as raw input for the number and intensity of light sources. These are put into a physical model of scattering due to air molecules and aerosoles to calculate cumulative sky brightness. Maps that show the enhanced sky brightness have been prepared for the entire world. The Bortle scale

4785-519: Is no replacement pollinator that would not be affected by the artificial light. This can lead to species decline of plants that are unable to reproduce, and change an area's longterm ecology . Among nocturnal insects, fireflies ( Coleoptera : Lampyridae, Phengodidae and Elateridae) are especially interesting study objects for light pollution, once they depend on their own light to reproduce and, consequently, are very sensitive to environmental levels of light. Fireflies are well known and interesting to

4930-574: Is not excessive in all developed countries. Amongst developed countries there are large variations in patterns of light use. American cities emit three to five times more light to space per capita compared to German cities. Over-illumination stems from several factors: Most of these issues can be readily corrected with available, inexpensive technology , and with the resolution of landlord/tenant practices that create barriers to rapid correction of these matters. Most importantly, public awareness would need to improve for industrialized countries to realize

5075-539: Is orchestrated by the natural diurnal patterns of light and dark, so disruption to these patterns impacts the ecological dynamics. Many species of marine plankton, such as Calanus copepods, can detect light levels as low as 0.1 μWm ; using this as a threshold a global atlas of marine Artificial Light at Night has been generated, showing its global widespread nature. Studies suggest that light pollution around lakes prevents zooplankton, such as Daphnia , from eating surface algae , causing algal blooms that can kill off

5220-827: Is physically located in Baltimore , Maryland on the Homewood campus of Johns Hopkins University , one of the 39 U.S. universities and seven international affiliates that make up the AURA consortium. STScI was established in 1981 after something of a power struggle between NASA and the scientific community at large. NASA had wanted to keep this function in-house, but scientists wanted it to be based in an academic establishment. The Space Telescope European Coordinating Facility (ST-ECF), established at Garching bei München near Munich in 1984, provided similar support for European astronomers until 2011, when these activities were moved to

5365-597: Is the excessive and unnecessary use of light. A large and overabundant amount of electricity is required to support light consumption in the United States. U.S homes consumed 81 billion kilowatthours (kWh) of electricity for lighting in 2020 according to the U.S. Energy Information Administration's (EIA). Additionally, the EIA reported that 208 billion kWh and 53 billion kWh of electricity were used for commercial and manufacturing buildings respectively in 2018. Light use

5510-585: The Challenger disaster brought the U.S. space program to a halt, grounded the Shuttle fleet, and forced the launch to be postponed for several years. During this delay the telescope was kept in a clean room, powered up and purged with nitrogen, until a launch could be rescheduled. This costly situation (about US$ 6 million per month) pushed the overall costs of the project higher. However, this delay allowed time for engineers to perform extensive tests, swap out

5655-479: The IAU , fear that light pollution will increase significantly, one of many concerns reported in the media regarding satellite overcrowding. Public discourse surrounding the continuing deployment of satellite constellations includes multiple petitions by astronomers and citizen scientists, and has raised questions about which regulatory bodies hold jurisdiction over human actions that obscure starlight. Measuring

5800-503: The International Dark-Sky Association has developed a set of model lighting ordinances. The Dark-Sky Association was started to reduce the light going up into the sky which reduces the visibility of stars (see Skyglow below). This is any light that is emitted more than 90° above nadir . By limiting light at this 90° mark they have also reduced the light output in the 80–90° range which creates most of

5945-512: The Keck telescopes , which required new sites, was eventually canceled. Three or four of the mountain's 13 existing telescopes must be dismantled over the next decade with the TMT proposal to be the last area on Mauna Kea on which any telescope would ever be built. With all the controversy, the building of telescopes has led to the creation of the Hawaii Night Sky Protection Act. As artificial light forms

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6090-457: The Milky Way galaxy. Light trespass occurs when unwanted light enters one's property, for instance, by shining over a neighbour's fence. A common light trespass problem occurs when a strong light enters the window of one's home from the outside , causing problems such as sleep deprivation . A number of cities in the U.S. have developed standards for outdoor lighting to protect the rights of their citizens against light trespass. To assist them,

6235-503: The Onizuka Center for International Astronomy (often called Hale Pōhaku), 7 miles (11 km) by unpaved steep road from the summit at 9,300 feet (2,800 m) above sea level. An adjacent visitor information station is located at 9,200 feet (2,800 m). The summit of Mauna Kea is so high that tourists are advised to stop at the visitor station for at least 30 minutes to acclimate to atmospheric conditions before continuing to

6380-493: The Solar cycle ) but given optimal conditions, the darkest possible sky has a brightness of about 22 magnitude/square arc second. If a full moon is present, the sky brightness increases to about 18 magnitude/sq. arcsecond depending on local atmospheric transparency, 40 times brighter than the darkest sky. In densely populated areas a sky brightness of 17 magnitude/sq. an arcsecond is not uncommon, or as much as 100 times brighter than

6525-612: The University of Hawaii placed a bid on behalf of the university. Jefferies had gained his reputation through observations at Sacramento Peak Observatory . The proposal was for a two-meter telescope to serve both the needs of NASA and the university. While large telescopes are not ordinarily awarded to universities without well-established astronomers, Jefferies and UH were awarded the NASA contract, infuriating Kuiper, who felt that "his mountain" had been "stolen" from him . Kuiper would abandon his site (the very first telescope on Mauna Kea) over

6670-452: The "hidden" harms of LAN, and many other topics. The environmental effects of LAN were mentioned as early as 1897, in a Los Angeles Times article. The following is an excerpt from that article, called "Electricity and English songbirds": Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble ) is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It

6815-404: The 1950s. In the 1980s a global dark-sky movement emerged with the founding of the International Dark-Sky Association (IDA). There are now such educational and advocacy organizations in many countries worldwide. About 83% of people, including 99% of Europeans and Americans, live under light-polluted skies that are more than 10% brighter than natural darkness. 80% of North Americans cannot see

6960-465: The 1991 comedy The Naked Gun 2½: The Smell of Fear , in a scene where historical disasters are displayed, Hubble is pictured with RMS Titanic and LZ 129 Hindenburg . Nonetheless, during the first three years of the Hubble mission, before the optical corrections, the telescope carried out a large number of productive observations of less demanding targets. The error was well characterized and stable, enabling astronomers to partially compensate for

7105-542: The CfDS handbook "Blinded by the Light?". Chapter 4, "Human health implications of light pollution" states that "...   light intrusion, even if dim, is likely to have measurable effects on sleep disruption and melatonin suppression. Even if these effects are relatively small from night to night, continuous chronic circadian, sleep and hormonal disruption may have longer-term health risks". The New York Academy of Sciences hosted

7250-693: The European Space Astronomy Centre. One complex task that falls to STScI is scheduling observations for the telescope. Hubble is in a low-Earth orbit to enable servicing missions, which results in most astronomical targets being occulted by the Earth for slightly less than half of each orbit. Observations cannot take place when the telescope passes through the South Atlantic Anomaly due to elevated radiation levels, and there are also sizable exclusion zones around

7395-584: The FOS. The final instrument was the HSP, designed and built at the University of Wisconsin–Madison . It was optimized for visible and ultraviolet light observations of variable stars and other astronomical objects varying in brightness. It could take up to 100,000 measurements per second with a photometric accuracy of about 2% or better. HST's guidance system can also be used as a scientific instrument. Its three Fine Guidance Sensors (FGS) are primarily used to keep

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7540-608: The Faint Object Spectrograph (FOS). WF/PC used a radial instrument bay, and the other four instruments were each installed in an axial instrument bay. WF/PC was a high-resolution imaging device primarily intended for optical observations. It was built by NASA's Jet Propulsion Laboratory , and incorporated a set of 48 filters isolating spectral lines of particular astrophysical interest. The instrument contained eight charge-coupled device (CCD) chips divided between two cameras, each using four CCDs. Each CCD has

7685-561: The HST is a Cassegrain reflector of Ritchey–Chrétien design , as are most large professional telescopes. This design, with two hyperbolic mirrors, is known for good imaging performance over a wide field of view, with the disadvantage that the mirrors have shapes that are hard to fabricate and test. The mirror and optical systems of the telescope determine the final performance, and they were designed to exacting specifications. Optical telescopes typically have mirrors polished to an accuracy of about

7830-654: The Island of Hawaii showing the "Hawaii Astronomy Station" near the Mauna Kea summit. After studying photos for NASA 's Apollo program that contained greater detail than any ground-based telescope, Gerard Kuiper began seeking an arid site for infrared studies. While he first began looking in Chile, he also made the decision to perform tests in the Hawaiian Islands. Tests on Maui 's Haleakalā were promising, but

7975-492: The Mauna Kea Ice Age Reserve. The 1982 plan was replaced in 2000 by an extension designed to serve until 2020: it instituted an Office of Mauna Kea Management, designated 525 acres (212 ha) for astronomy, and shifted the remaining 10,763 acres (4,356 ha) to "natural and cultural preservation". This plan was further revised to address concern expressed in the Hawaiian community that a lack of respect

8120-453: The Mauna Kea observatories that continues to grow. Over the years, the opposition to the observatories may have become the most visible example of the conflict science has encountered over access and use of environmental and culturally significant sites. Opposition to development grew shortly after expansion of the observatories commenced. Once access was opened up by the roadway to the summit, skiers began using it for recreation and objected when

8265-624: The NASA Infrared Telescope Facility (NITF), discovered the first Super-Planet. In October, 2011, the Nobel Prize in Physics was awarded to Saul Perlmutter , Brian P. Schmidt , and Adam G. Riess ; the prize recognized their findings, based on research on supernovae at the observatories, that dark energy is a force causing the universe to expand at an accelerating rate . The Reserve was established in 1968, and

8410-515: The OTA was not designed with optimum infrared performance in mind—for example, the mirrors are kept at stable (and warm, about 15 °C) temperatures by heaters. This limits Hubble's performance as an infrared telescope. Perkin-Elmer (PE) intended to use custom-built and extremely sophisticated computer-controlled polishing machines to grind the mirror to the required shape. However, in case their cutting-edge technology ran into difficulties, NASA demanded that PE sub-contract to Kodak to construct

8555-483: The October 15, 2006 Kiholo Bay earthquake and aftershocks. JCMT was performing an inclinometry run and recorded the earthquake on its tilt sensors. Both CFHT and W. M. Keck Observatory were operational and back online by October 19. Light pollution Light pollution is the presence of any unwanted, inappropriate, or excessive artificial lighting . In a descriptive sense, the term light pollution refers to

8700-425: The Shuttle servicing missions. COSTAR was a corrective optics device rather than a science instrument, but occupied one of the four axial instrument bays. Since the final servicing mission in 2009, the four active instruments have been ACS, COS, STIS and WFC3. NICMOS is kept in hibernation, but may be revived if WFC3 were to fail in the future. Of the former instruments, three (COSTAR, FOS and WFPC2) are displayed in

8845-725: The Smithsonian National Air and Space Museum . The FOC is in the Dornier museum, Germany. The HSP is in the Space Place at the University of Wisconsin–Madison . The first WFPC was dismantled, and some components were then re-used in WFC3. Within weeks of the launch of the telescope, the returned images indicated a serious problem with the optical system. Although the first images appeared to be sharper than those of ground-based telescopes, Hubble failed to achieve

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8990-518: The Southern Economic Journal indicates that light pollution may increase by 13% in preterm births before 23 weeks of gestation. While light at night can be beneficial, neutral, or damaging for individual species , its presence invariably disturbs ecosystems. For example, some species of spiders avoid lit areas, while other species are happy to build their webs directly on lamp posts. Since lamp posts attract many flying insects,

9135-616: The State of Hawaiʻi agreeing to build a reliable, all weather roadway to the summit. Building began in 1967 and first light was seen in 1970. Other groups began requesting subleases on the newly accessible mountaintop. By 1970, two 24 in (0.6 m) telescopes had been constructed by the United States Air Force and Lowell Observatory . In 1973, Canada and France agreed to build the 3.6 m CFHT on Mauna Kea. However, local organizations started to raise concerns about

9280-575: The Sun (precluding observations of Mercury ), Moon and Earth. The solar avoidance angle is about 50°, to keep sunlight from illuminating any part of the OTA. Earth and Moon avoidance keeps bright light out of the FGSs, and keeps scattered light from entering the instruments. If the FGSs are turned off, the Moon and Earth can be observed. Earth observations were used very early in the program to generate flat-fields for

9425-415: The U.S. National Academy of Sciences recommended development of a space telescope as part of the space program , and in 1965, Spitzer was appointed as head of a committee given the task of defining scientific objectives for a large space telescope. Also crucial was the work of Nancy Grace Roman , the "Mother of Hubble". Well before it became an official NASA project, she gave public lectures touting

9570-453: The U.S. Fish and Wildlife Service of the number of birds killed after being attracted to tall towers range from four to five million per year to an order of magnitude higher. The Fatal Light Awareness Program (FLAP) works with building owners in Toronto , Ontario , Canada and other cities to reduce mortality of birds by turning out lights during migration periods. Another study has found that

9715-526: The U.S. Sky quality in the U.S. ranges from pristine ( Capitol Reef National Park and Big Bend National Park ) to severely degraded ( Santa Monica Mountains National Recreation Area and Biscayne National Park ). The National Park Service Night Sky Program monitoring database is available online (2015). Light pollution in Hong Kong was declared the 'worst on the planet' in March 2013. In June 2016, it

9860-513: The University based management. Locals never agreed to thirteen telescopes atop the mountain and demand a say in the legislation process. House Bill 2024 pushes for new stewardship on the summit. The area will be integrated in terms of management. Some land will be jurisdicted by the local community. The Bill pushes for future laws and regulations in terms of new building. As always, the cultural and environmental sites will be heavily recognized as

10005-745: The WFPC1 instrument. There is a so-called continuous viewing zone (CVZ), within roughly 24° of Hubble's orbital poles , in which targets are not occulted for long periods. Due to the precession of the orbit, the location of the CVZ moves slowly over a period of eight weeks. Because the limb of the Earth is always within about 30° of regions within the CVZ, the brightness of scattered earthshine may be elevated for long periods during CVZ observations. Hubble orbits in low Earth orbit at an altitude of approximately 540 kilometers (340 mi) and an inclination of 28.5°. The position along its orbit changes over time in

10150-428: The atmosphere The effect of sky glow can be harmful in astronomy and on the health of many organisms. It worsens the visibility of the stars, the Milky Way , and significantly increases the natural light levels at night. Also contributing to light pollution are artificial satellites . With increasing numbers of satellite constellations such as OneWeb and Starlink , members of the astronomical community, notably

10295-705: The blue band. In North America the situation is comparable. There is a significant problem with light pollution ranging from the Canadian Maritime Provinces to the American Southwest. The International Dark-Sky Association works to designate areas that have high-quality night skies. These areas are supported by communities and organizations that are dedicated to reducing light pollution (e.g. Dark-sky preserve ). The National Park Service Natural Sounds and Night Skies Division has measured night sky quality in national park units across

10440-475: The competition and begin work in Arizona on a different NASA project. After considerable testing by Jefferies' team, the best locations were determined to be near the summit at the top of the cinder cones. Testing also determined Mauna Kea to be superb for nighttime viewing due to many factors, including the thin air, constant trade winds and being surrounded by sea. Jefferies would build a 2.24 meter telescope with

10585-618: The construction. The two initial, primary computers on the HST were the 1.25 MHz DF-224 system, built by Rockwell Autonetics, which contained three redundant CPUs, and two redundant NSSC-1 (NASA Standard Spacecraft Computer, Model 1) systems, developed by Westinghouse and GSFC using diode–transistor logic (DTL). A co-processor for the DF-224 was added during Servicing Mission 1 in 1993, which consisted of two redundant strings of an Intel-based 80386 processor with an 80387 math co-processor. The DF-224 and its 386 co-processor were replaced by

10730-406: The day, because direction of natural polarization of sun light and its reflection is a source of information for a lot of animals). This form of pollution is named polarized light pollution (PLP). Unnatural polarized light sources can trigger maladaptive behaviors in polarization-sensitive taxa and alter ecological interactions. Lights on tall structures can disorient migrating birds. Estimates by

10875-498: The defective mirror by using sophisticated image processing techniques such as deconvolution . A commission headed by Lew Allen , director of the Jet Propulsion Laboratory , was established to determine how the error could have arisen. The Allen Commission found that a reflective null corrector , a testing device used to achieve a properly shaped non-spherical mirror, had been incorrectly assembled—one lens

11020-560: The development and trial of new lighting technologies in the North Sea. In early 2007, the lights were installed on the Shell production platform L15. The experiment proved a great success since the number of birds circling the platform declined by 50 to 90%. Birds migrate at night for several reasons. Save water from dehydration in hot day flying and part of the bird's navigation system works with stars in some way. With city light outshining

11165-598: The direct lighting effect by adding softening filters or other solutions, though intensity will be reduced. Glare can be categorized into different types. One such classification is described in a book by Bob Mizon, coordinator for the British Astronomical Association's Campaign for Dark Skies, as follows: According to Mario Motta, president of the Massachusetts Medical Society , "...   glare from bad lighting

11310-416: The effect of sky glow on a global scale is a complex procedure. The natural atmosphere is not completely dark, even in the absence of terrestrial sources of light and illumination from the Moon. This is caused by two main sources: airglow and scattered light . At high altitudes, primarily above the mesosphere , there is enough UV radiation from the sun at very short wavelengths to cause ionization . When

11455-414: The effects of any poorly implemented lighting sources, during the day or night. Light pollution can be understood not only as a phenomenon resulting from a specific source or kind of pollution, but also as a contributor to the wider, collective impact of various sources of pollution. Although this type of pollution can exist throughout the day, its effects are magnified during the night with the contrast of

11600-573: The effort is now used in the 2.4 m telescope at the Magdalena Ridge Observatory . Construction of the Perkin-Elmer mirror began in 1979, starting with a blank manufactured by Corning from their ultra-low expansion glass. To keep the mirror's weight to a minimum it consisted of top and bottom plates, each 25 mm (0.98 in) thick, sandwiching a honeycomb lattice. Perkin-Elmer simulated microgravity by supporting

11745-437: The entire site was sacred and that developing the mountain, even for science, would spoil the area. Environmentalists were concerned about rare native bird populations and other citizens of Hilo were concerned about the sight of the domes from the city. Using town hall meetings, Jefferies was able to overcome opposition by weighing the economic advantage and prestige the island would receive. There has been substantial opposition to

11890-485: The environmental impact of the observatory. This led the Department of Land and Natural Resources to prepare an initial management plan, drafted in 1977 and supplemented in 1980. In January 1982, the University of Hawaiʻi Board of Regents approved a plan to support the continued development of scientific facilities at the site. In 1998, 2,033 acres (823 ha) were transferred from the observatory lease to supplement

12035-460: The finch billed honeycreepers existing on the island. Over 50% of native bird species had been killed off due to loss of habitat from early western settlers or the introduction of non-native species competing for resources. Hunters and sportsmen were concerned that the hunting of feral animals would be affected by the telescope operations. A "Save Mauna Kea" movement was inspired by the proliferation of telescopes, with opposition believing development of

12180-501: The first Orbiting Astronomical Observatory (OAO) mission. OAO-1's battery failed after three days, terminating the mission. It was followed by Orbiting Astronomical Observatory 2 (OAO-2), which carried out ultraviolet observations of stars and galaxies from its launch in 1968 until 1972, well beyond its original planned lifetime of one year. The OSO and OAO missions demonstrated the important role space-based observations could play in astronomy. In 1968, NASA developed firm plans for

12325-465: The first generation instruments for the telescope, as well as the solar cells that would power it, and staff to work on the telescope in the United States, in return for European astronomers being guaranteed at least 15% of the observing time on the telescope. Congress eventually approved funding of US$ 36 million for 1978, and the design of the LST began in earnest, aiming for a launch date of 1983. In 1983,

12470-521: The general public (unlike many other insects) and are easily spotted by non-experts, and, due to their sensibility and rapid response to environmental changes, good bioindicators for artificial night lighting. Significant declines in some insect populations have been suggested as being at least partially mediated by artificial lights at night. A 2009 study also suggests deleterious impacts on animals and ecosystems because of perturbation of polarized light or artificial polarization of light (even during

12615-407: The higher layers and thus no appreciable ionization occurs. Apart from emitting light, the sky also scatters incoming light, primarily from distant stars and the Milky Way , but also the zodiacal light , sunlight that is reflected and backscattered from interplanetary dust particles. The amount of airglow and zodiacal light is quite varied (depending, amongst other things on sunspot activity and

12760-563: The highest levels of ALAN reported the highest number of cases of breast cancer. Seoul, which had the highest levels of light pollution, had 34.4% more cases of breast cancer than Ganwon-do, which had the lowest levels of light pollution. This suggested a high correlation between ALAN and the prevalence of breast cancer. It was also found that there was no correlation between other types of cancer such as cervical or lung cancer and ALAN levels. A more recent discussion (2009), written by Professor Steven Lockley, Harvard Medical School, can be found in

12905-992: The human body suggests that a variety of adverse health effects may be caused by light pollution or excessive light exposure, and some lighting design textbooks use human health as an explicit criterion for proper interior lighting. Health effects of over-illumination or improper spectral composition of light may include: increased headache incidence, worker fatigue , medically defined stress , decrease in sexual function and increase in anxiety. Likewise, animal models have been studied demonstrating unavoidable light to produce adverse effect on mood and anxiety. For those who need to be awake at night, light at night also has an acute effect on alertness and mood. Outdoor artificial light at night – exposure to contemporary types such as current types of street lighting – has been linked to risks for obesity, mental disorders, diabetes , and potentially other health issues by preliminary studies. In 2007, "shift work that involves circadian disruption"

13050-467: The intended −1.00230 . The same number was also derived by analyzing the null corrector used by Perkin-Elmer to figure the mirror, as well as by analyzing interferograms obtained during ground testing of the mirror. Because of the way the HST's instruments were designed, two different sets of correctors were required. The design of the Wide Field and Planetary Camera 2, already planned to replace

13195-424: The ions collide with electrically neutral particles they recombine and emit photons in the process, causing airglow . The degree of ionization is sufficiently large to allow a constant emission of radiation even during the night when the upper atmosphere is in the Earth's shadow. Lower in the atmosphere all the solar photons with energies above the ionization potential of N 2 and O 2 have already been absorbed by

13340-424: The lakes' plants and lower water quality. Light pollution may also affect ecosystems in other ways. For example, entomologists have documented that nighttime light may interfere with the ability of moths and other nocturnal insects to navigate. It can also negative impact on insect development and reproduction. Night-blooming flowers that depend on moths for pollination may be affected by night lighting, as there

13485-424: The large payoff in reducing over-illumination. In certain cases, an over-illumination lighting technique may be needed. For example, indirect lighting is often used to obtain a "softer" look, since hard direct lighting is generally found less desirable for certain surfaces, such as skin. The indirect lighting method is perceived as cozier and suits bars, restaurants, and living quarters. It is also possible to block

13630-444: The late 1990s showed that the entire area consisting of southern England, Netherlands, Belgium, West Germany, and northern France have a sky brightness of at least two to four times normal. The only places in continental Europe where the sky can attain its natural darkness are in northern Scandinavia and in islands far from the continent. The growth of light pollution on the green band has been 11% from 2012–2013 to 2014–2020, and 24% on

13775-413: The launch date of the telescope to October 1984. The mirror was completed by the end of 1981; it was washed using 9,100 L (2,000 imp gal; 2,400 US gal) of hot, deionized water and then received a reflective coating of 65 nm-thick aluminum and a protective coating of 25 nm-thick magnesium fluoride . Doubts continued to be expressed about Perkin-Elmer's competence on

13920-407: The light itself on the eye.) Light clutter refers to excessive groupings of lights. Groupings of lights may generate confusion, distract from obstacles (including those that they may be intended to illuminate), and potentially cause accidents. Clutter is particularly noticeable on roads where the street lights are badly designed, or where brightly lit advertisements surround the roadways. Depending on

14065-546: The light trespass issues. U.S. federal agencies may also enforce standards and process complaints within their areas of jurisdiction. For instance, in the case of light trespass by white strobe lighting from communication towers in excess of FAA minimum lighting requirements the Federal Communications Commission maintains an Antenna Structure Registration database information which citizens may use to identify offending structures and provides

14210-462: The lights produced by the Post Tower has affected 25 bird species. As a result, they discovered that decreasing the use of excessive lights increased the survival rate of bird species. Similar disorientation has also been noted for bird species migrating close to offshore production and drilling facilities. Studies carried out by Nederlandse Aardolie Maatschappij b.v. (NAM) and Shell have led to

14355-415: The mirror being ground very precisely but to the wrong shape. During fabrication, a few tests using conventional null correctors correctly reported spherical aberration . But these results were dismissed, thus missing the opportunity to catch the error, because the reflective null corrector was considered more accurate. The commission blamed the failings primarily on Perkin-Elmer. Relations between NASA and

14500-414: The mirror from the back with 130 rods that exerted varying amounts of force. This ensured the mirror's final shape would be correct and to specification when deployed. Mirror polishing continued until May 1981. NASA reports at the time questioned Perkin-Elmer's managerial structure, and the polishing began to slip behind schedule and over budget. To save money, NASA halted work on the back-up mirror and moved

14645-427: The mirror. While the commission heavily criticized Perkin-Elmer for these managerial failings, NASA was also criticized for not picking up on the quality control shortcomings, such as relying totally on test results from a single instrument. Many feared that Hubble would be abandoned. The design of the telescope had always incorporated servicing missions, and astronomers immediately began to seek potential solutions to

14790-499: The most detailed visible light images, allowing a deep view into space. Many Hubble observations have led to breakthroughs in astrophysics , such as determining the rate of expansion of the universe . Space telescopes were proposed as early as 1923, and the Hubble telescope was funded and built in the 1970s by the United States space agency NASA with contributions from the European Space Agency . Its intended launch

14935-431: The motives of the person or organization that installed the lights, their placement and design can even be intended to distract drivers, and can contribute to accidents. Sky glow is the bright haze above cities that is produced from excessive artificial lighting at night. This type of light pollution is created from artificial light reflecting in the sky and bouncing around the different types of particles that reside in

15080-537: The mountain to be sacrilegious. Native Hawaiian non-profit groups, such as Kahea, whose goals are the protection of cultural heritage and the environment, oppose development on Mauna Kea as a sacred space to the Hawaiian religion. The land is protected by the United States Historical Preservation Act due to its significance to Hawaiian culture, but still allowed development. A number of the telescopes sustained minor damage during

15225-466: The mountain was too low in the inversion layer and often covered by clouds. On the "Big Island" of Hawaiʻi, Mauna Kea is considered the second-highest island mountain in the world. While the summit is often covered with snow, the air is extremely dry. Kuiper began looking into the possibility of an observatory on Mauna Kea. After testing, he discovered the low humidity was perfect for infrared signals. He persuaded Hawaiʻi Governor John A. Burns to bulldoze

15370-521: The natural illumination cycles provided by the moon in the marine environment are considerably disrupted by light pollution, with only nights around the full moon providing greater radiances, and over a given month lunar dosages may be a factor of 6 less than light pollution dosages. In September 2009, the 9th European Dark-Sky Symposium in Armagh, Northern Ireland had a session on the environmental effects of light at night (LAN). It dealt with bats, turtles,

15515-452: The next hurdle for NASA was to obtain funding for the instrument, which would be far more costly than any Earth-based telescope. The U.S. Congress questioned many aspects of the proposed budget for the telescope and forced cuts in the budget for the planning stages, which at the time consisted of very detailed studies of potential instruments and hardware for the telescope. In 1974, public spending cuts led to Congress deleting all funding for

15660-802: The night sky, birds (and also about mammals) no longer navigate by stars. Sea turtle hatchlings emerging from nests on beaches are another casualty of light pollution. It is a common misconception that hatchling sea turtles are attracted to the moon. Rather, they find the ocean by moving away from the dark silhouette of dunes and their vegetation, a behavior with which artificial lights interfere. The breeding activity and reproductive phenology of toads, however, are cued by moonlight. Juvenile seabirds are also disoriented by lights as they leave their nests and fly out to sea, causing events of high mortality. Amphibians and reptiles are also affected by light pollution. Introduced light sources during normally dark periods can disrupt levels of melatonin production. Melatonin

15805-666: The older 1801 version). The WFPC-1 was replaced by the WFPC-2 during Servicing Mission 1 in 1993, which was then replaced by the Wide Field Camera 3 (WFC3) during Servicing Mission 4 in 2009. The upgrade extended Hubble's capability of seeing deeper into the universe and providing images in three broad regions of the spectrum. When launched, the HST carried five scientific instruments: the Wide Field and Planetary Camera (WF/PC), Goddard High Resolution Spectrograph (GHRS), High Speed Photometer (HSP), Faint Object Camera (FOC) and

15950-411: The optics company had been severely strained during the telescope construction, due to frequent schedule slippage and cost overruns. NASA found that Perkin-Elmer did not review or supervise the mirror construction adequately, did not assign its best optical scientists to the project (as it had for the prototype), and in particular did not involve the optical designers in the construction and verification of

16095-425: The problem that could be applied at the first servicing mission, scheduled for 1993. While Kodak had ground a back-up mirror for Hubble, it would have been impossible to replace the mirror in orbit, and too expensive and time-consuming to bring the telescope back to Earth for a refit. Instead, the fact that the mirror had been ground so precisely to the wrong shape led to the design of new optical components with exactly

16240-585: The project. Hubble's cumulative costs are estimated to be about US$ 11.3 billion in 2015 dollars, which include all subsequent servicing costs, but not ongoing operations, making it the most expensive science mission in NASA history. Hubble accommodates five science instruments at a given time, plus the Fine Guidance Sensors , which are mainly used for aiming the telescope but are occasionally used for scientific astrometry measurements. Early instruments were replaced with more advanced ones during

16385-401: The public in order to push legislative change. However, because it is a man-made phenomenon, addressing its impacts on humans and the environment has political, social, and economic considerations. Light pollution is the presence of anthropogenic artificial light in otherwise dark conditions. The term is most commonly used in relation to in the outdoor environment and surrounding, but

16530-485: The road was closed as a precaution against vandalism when the telescopes were being built. Hunters voiced concerns, as did the Hawaiian Audubon Society who were supported by Governor George Ariyoshi . The Audubon Society objected to further development on Mauna Kea over concerns to habitat of the endangered Palila , a species endemic to only specific parts of this mountain. The bird is the last of

16675-409: The same error but in the opposite sense, to be added to the telescope at the servicing mission, effectively acting as " spectacles " to correct the spherical aberration. The first step was a precise characterization of the error in the main mirror. Working backwards from images of point sources, astronomers determined that the conic constant of the mirror as built was −1.01390 ± 0.0002 , instead of

16820-439: The scientific value of the telescope. After it was approved, she became the program scientist, setting up the steering committee in charge of making astronomer needs feasible to implement and writing testimony to Congress throughout the 1970s to advocate continued funding of the telescope. Her work as project scientist helped set the standards for NASA's operation of large scientific projects. Space-based astronomy had begun on

16965-533: The sky's darkness. It has been estimated that 83 percent of the world's people live under light-polluted skies and that 23 percent of the world's land area is affected by skyglow . The area affected by artificial illumination continues to increase. A major side effect of urbanization , light pollution is blamed for compromising health, disrupting ecosystems, and spoiling aesthetic environments. Studies show that urban areas are more at risk. Globally, it has increased by at least 49% from 1992 to 2017. Light pollution

17110-405: The spacecraft in which the telescope and instruments would be housed proceeded somewhat more smoothly than the construction of the OTA, Lockheed experienced some budget and schedule slippage, and by the summer 1985, construction of the spacecraft was 30% over budget and three months behind schedule. An MSFC report said Lockheed tended to rely on NASA directions rather than take their own initiative in

17255-424: The spacecraft. Hubble features a 2.4 m (7 ft 10 in) mirror, and its five main instruments observe in the ultraviolet , visible , and near-infrared regions of the electromagnetic spectrum . Hubble's orbit outside the distortion of Earth's atmosphere allows it to capture extremely high-resolution images with substantially lower background light than ground-based telescopes. It has recorded some of

17400-826: The spectrum are covered by the Compton Gamma Ray Observatory , the Chandra X-ray Observatory , and the Spitzer Space Telescope (which covers the infrared bands). The mid-IR-to-visible band successor to the Hubble telescope is the James Webb Space Telescope (JWST), which was launched on December 25, 2021, with the Nancy Grace Roman Space Telescope due to follow in 2027. In 1923, Hermann Oberth —considered

17545-508: The spiders that tolerate the light gain an advantage over the spiders that avoid it. This is a simple example of the way in which species frequencies and food webs can be disturbed by the introduction of light at night. Light pollution poses a serious threat in particular to nocturnal wildlife, having negative impacts on plant and animal physiology. It can confuse animal navigation , alter competitive interactions, change predator-prey relations, and cause physiological harm. The rhythm of life

17690-500: The summit of Mauna Kea. CSO, UKIRT, and Hoku Kea are scheduled for decommissioning as part of the Mauna Kea Comprehensive Management Plan. In Honolulu, the governor and legislature, enthusiastic about the development, set aside an even larger area for the observatory after the initial project, causing opposition on the Big Island, in the city of Hilo . Native Hawaiians (kānaka ʻōiwi) believed

17835-489: The summit, and scientists often stay at Hale Pōhaku for eight hours or more before spending a full night at observatories on the summit, with some telescopes requiring observers to spend one full night at Hale Pōhaku before working at the summit. Telescopes found at the summit of Mauna Kea are funded by government agencies of various nations. The University of Hawaiʻi directly administers two telescopes. In total, there are twelve facilities housing thirteen telescopes at or around

17980-468: The technology to allow this was soon to become available. The continuing success of the OAO program encouraged increasingly strong consensus within the astronomical community that the LST should be a major goal. In 1970, NASA established two committees, one to plan the engineering side of the space telescope project, and the other to determine the scientific goals of the mission. Once these had been established,

18125-560: The telescope accurately pointed during an observation, but can also be used to carry out extremely accurate astrometry ; measurements accurate to within 0.0003 arcseconds have been achieved. The Space Telescope Science Institute (STScI) is responsible for the scientific operation of the telescope and the delivery of data products to astronomers. STScI is operated by the Association of Universities for Research in Astronomy (AURA) and

18270-418: The telescope project. In 1977, then NASA Administrator James C. Fletcher proposed a token $ 5 million for Hubble in NASA's budget. Then NASA Associate Administrator for Space Science, Noel Hinners , instead cut all funding for Hubble, gambling that this would galvanize the scientific community into fighting for full funding. As Hinners recalls: It was clear that year that we weren't going to be able to get

18415-422: The telescope was named after Edwin Hubble , who confirmed one of the greatest scientific discoveries of the 20th century, made by Georges Lemaître , that the universe is expanding . Once the Space Telescope project had been given the go-ahead, work on the program was divided among many institutions. Marshall Space Flight Center (MSFC) was given responsibility for the design, development, and construction of

18560-575: The telescope, including all five of the main instruments. The fifth mission was initially canceled on safety grounds following the Columbia disaster (2003), but after NASA administrator Michael D. Griffin approved it, the servicing mission was completed in 2009. Hubble completed 30 years of operation in April 2020 and is predicted to last until 2030 to 2040. Hubble is the visible light telescope in NASA's Great Observatories program ; other parts of

18705-436: The telescope, while Goddard Space Flight Center was given overall control of the scientific instruments and ground-control center for the mission. MSFC commissioned the optics company Perkin-Elmer to design and build the optical telescope assembly (OTA) and Fine Guidance Sensors for the space telescope. Lockheed was commissioned to construct and integrate the spacecraft in which the telescope would be housed. Optically,

18850-501: The telescope. A shroud of multi-layer insulation keeps the temperature within the telescope stable and surrounds a light aluminum shell in which the telescope and instruments sit. Within the shell, a graphite-epoxy frame keeps the working parts of the telescope firmly aligned. Because graphite composites are hygroscopic , there was a risk that water vapor absorbed by the truss while in Lockheed's clean room would later be expressed in

18995-436: The troops. So I advocated that we not put anything in. I don't remember any of the detailed discussions or whether there were any, but Jim went along with that so we zeroed it out. It had, from my perspective, the desired impact of stimulating the astronomy community to renew their efforts on the lobbying front. While I like to think in hindsight it was a brilliant political move, I'm not sure I thought it through all that well. It

19140-455: The two main advantages that a space-based observatory would have over ground-based telescopes. First, the angular resolution (the smallest separation at which objects can be clearly distinguished) would be limited only by diffraction , rather than by the turbulence in the atmosphere, which causes stars to twinkle, known to astronomers as seeing . At that time ground-based telescopes were limited to resolutions of 0.5–1.0 arcseconds , compared to

19285-409: The usefulness of the telescope for faint objects or high-contrast imaging. This meant nearly all the cosmological programs were essentially impossible, since they required observation of exceptionally faint objects. This led politicians to question NASA's competence, scientists to rue the cost which could have gone to more productive endeavors, and comedians to make jokes about NASA and the telescope. In

19430-535: The vacuum of space; resulting in the telescope's instruments being covered by ice. To reduce that risk, a nitrogen gas purge was performed before launching the telescope into space. As well as electrical power systems, the Pointing Control System controls HST orientation using five types of sensors (magnetic sensors, optical sensors, and six gyroscopes) and two types of actuators ( reaction wheels and magnetic torquers ). While construction of

19575-729: The visible and infrared spectrum, three in the submillimeter spectrum, and one in the radio spectrum, with mirrors or dishes ranging from 0.9 to 25 m (3 to 82 ft). In comparison, the Hubble Space Telescope has a 2.4 m (7.9 ft) mirror, similar in size to the UH88, now the second smallest telescope on the mountain. Planned new telescopes, including the Thirty Meter Telescope , have attracted controversy due to their potential cultural and ecological impact. The multi-telescope "outrigger" extension to

19720-406: The wrong shape. Although it was believed to be one of the most precisely figured optical mirrors ever made, smooth to about 10 nanometers, the outer perimeter was too flat by about 2200 nanometers (about 1 ⁄ 450 mm or 1 ⁄ 11000 inch). This difference was catastrophic, introducing severe spherical aberration, a flaw in which light reflecting off the edge of a mirror focuses on

19865-492: Was being shown toward the cultural value the mountain embodied to the region's indigenous people. As of 2012, the Mauna Kea Science Reserve has 13 observation facilities, each funded by as many as 11 countries. It is one of the world's premier observatories for optical, infrared, and submillimeter astronomy, and in 2009 was the largest measured by light gathering power. There are nine telescopes working in

20010-534: Was due to be observed. Engineering support for HST is provided by NASA and contractor personnel at the Goddard Space Flight Center in Greenbelt, Maryland , 48 km (30 mi) south of the STScI. Hubble's operation is monitored 24 hours per day by four teams of flight controllers who make up Hubble's Flight Operations Team. By January 1986, the planned launch date for Hubble that October looked feasible, but

20155-485: Was estimated that one third of the world's population could no longer see the Milky Way, including 80% of Americans and 60% of Europeans. Singapore was found to be the most light-polluted country in the world. Over the past 21 years, China's provincial capital cities have seen a major increase in light pollution, with hotspots along the eastern coastline region. Medical research on the effects of excessive light on

20300-480: Was forced to postpone the launch date until March and then September 1986. By this time, the total project budget had risen to US$ 1.175 billion. The spacecraft in which the telescope and instruments were to be housed was another major engineering challenge. It would have to withstand frequent passages from direct sunlight into the darkness of Earth's shadow , which would cause major changes in temperature, while being stable enough to allow extremely accurate pointing of

20445-529: Was in 1983, but the project was beset by technical delays, budget problems, and the 1986 Challenger disaster . Hubble was finally launched in 1990, but its main mirror had been ground incorrectly, resulting in spherical aberration that compromised the telescope's capabilities. The optics were corrected to their intended quality by a servicing mission in 1993. Hubble is the only telescope designed to be maintained in space by astronauts. Five Space Shuttle missions have repaired, upgraded, and replaced systems on

20590-584: Was listed as a probable carcinogen by the World Health Organization's International Agency for Research on Cancer. (IARC Press release No. 180). Multiple studies have documented a correlation between night shift work and the increased incidence of breast and prostate cancer. One study which examined the link between exposure to artificial light at night (ALAN) and levels of breast cancer in South Korea found that regions which had

20735-516: Was not the first space telescope , but it is one of the largest and most versatile, renowned as a vital research tool and as a public relations boon for astronomy . The Hubble telescope is named after astronomer Edwin Hubble and is one of NASA's Great Observatories . The Space Telescope Science Institute (STScI) selects Hubble's targets and processes the resulting data, while the Goddard Space Flight Center (GSFC) controls

20880-414: Was out of position by 1.3 mm (0.051 in). During the initial grinding and polishing of the mirror, Perkin-Elmer analyzed its surface with two conventional refractive null correctors. However, for the final manufacturing step ( figuring ), they switched to the custom-built reflective null corrector, designed explicitly to meet very strict tolerances. The incorrect assembly of this device resulted in

21025-510: Was something that was spur of the moment. [...] $ 5 million would let them think that all is well anyway, but it's not. So let's give them a message. My own thinking, get them stimulated to get into action. Zeroing it out would certainly give that message. I think it was as simple as that. Didn't talk to anybody else about doing it first, just, "Let's go do that". Voila, it worked. Don't know whether I'd do that again. The political ploy worked. In response to Hubble being zeroed out of NASA's budget,

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