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107-580: The GMT will feature seven of the world's largest mirrors, collectively providing a light-collecting area of 368 square meters. It is expected to have a resolving power approximately 10 times greater than the Hubble Space Telescope and four times greater than the James Webb Space Telescope . However, it will not be able to observe in the same infrared frequencies as space-based telescopes. The GMT will be used to explore

214-580: 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

321-732: 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

428-613: A 40,000 square foot facility to manufacture the Giant Magellan Telescope mount in Rockford, Illinois in December 2021. As of 2022, construction of the telescope mount was underway and is expected to be completed in 2025. The telescope mount consists of seven “cells” that hold and protect the telescope’s 18-ton primary mirrors. The mirror support system does not have a traditional internal load-carrying frame. Instead,

535-488: 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

642-419: 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

749-586: 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

856-437: 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

963-546: 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

1070-461: 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

1177-475: A number of hydrostatic bearings to allow the telescope mount to glide frictionlessly in three degrees of freedom. In October 2019, GMTO Corporation announced the signing of a contract with German company MT Mechatronics (subsidiary of OHB SE) and Illinois-based Ingersoll Machine Tools, to design, build and install the Giant Magellan Telescope’s structure. Ingersoll Machine Tools finished constructing

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1284-554: 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

1391-449: 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

1498-551: 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

1605-565: 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

1712-507: 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

1819-478: 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,

1926-403: 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

2033-524: A thermal equilibrium within the telescope enclosure and reduce ambient thermal gradients across the primary mirror surface. The enclosure design provides the telescope pier with a seismic isolation system that can survive the strongest earthquakes expected over the 50-year lifetime of the observatory and will allow the telescope to quickly return to operations after the more frequent, but less intense seismic events that are experienced several times per month. In March 2022, engineering and architecture firm IDOM

2140-732: 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

2247-406: 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

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2354-452: A wide range of astrophysical phenomena, including the search for signs of life on exoplanets and the study of the cosmic origins of chemical elements. The casting of the GMT's primary mirrors began in 2005, and construction at the site started in 2015. By 2023, all seven primary mirrors had been cast, the first of seven adaptive secondary mirrors was under construction, and the telescope mount

2461-462: Is a space telescope that was launched into low Earth orbit in 1990 and remains in operation. It 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

2568-607: Is also home to the Magellan Telescopes . The observatory is situated approximately 115 km (71 mi) north-northeast of La Serena , and 180 km (112 mi) south of Copiapó , at an altitude of 2,516 m (8,255 ft). The site has been owned by the Carnegie Institution for Science since 1960. Las Campanas was selected as the location for the GMT due to its exceptional astronomical seeing conditions and clear weather throughout much of

2675-411: Is designed to take advantage of the telescope’s four observing modes. The telescope will have an advanced fiber-optic system that uses tiny robotic positioners to expand the capabilities of the spectrographs by allowing them to access the highest resolution of all telescopes in the 30-meter class over a full field of view of 20 arcminutes. Using this system, it is possible to observe multiple targets over

2782-400: Is easily visible in satellite imagery at 34°09′21″N 118°08′00″W  /  34.15591°N 118.13345°W  / 34.15591; -118.13345  ( Giant Magellan Telescope outline drawing ) . The Giant Magellan Telescope’s Adaptive Secondary Mirror consists of seven segments about 1.1 meters in diameter. They are deformable “adaptive optics” mirrors tasked with correcting

2889-480: Is expected to be delivered to Chile at the end of 2025. The Giant Magellan Telescope enclosure is a 65-meter-tall structure that shelters the telescope’s mirrors and components from the extreme weather and earthquakes in the Atacama Desert, Chile. The 4,800-ton enclosure can complete a full rotation in a little more than three minutes and is designed with a closed-cycle forced-air convection system to maintain

2996-693: Is one of a new class of telescopes called extremely large telescopes with each design being much larger than existing ground-based telescopes. Other planned extremely large telescopes include the Extremely Large Telescope and the Thirty Meter Telescope . The Giant Magellan Telescope is the work of the GMTO Corporation, an international consortium of research institutions representing seven countries from Australia, Brazil, Chile, Israel, South Korea, Taiwan, and

3103-827: 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

3210-412: Is that the outer six mirror segments will be off-axis , and although identical to each other, will not be individually radially symmetrical, necessitating a modification of the usual polishing and testing procedures. The mirrors are being constructed by the University of Arizona 's Steward Observatory Richard F. Caris Mirror Lab. The casting of each mirror uses 20 tons of E6 borosilicate glass from

3317-429: Is the only 30-meter class telescope with ground layer adaptive optics over a full field of view. The Giant Magellan Telescope's Gregorian design can accommodate up to 10 visible to mid-infrared science instruments, from wide field imagers and spectrographs that reach hundreds of objects at one time, to high-resolution imagers and spectrographs that can study exoplanets and even find biosignatures . Each science instrument

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3424-421: Is used to maintain a thermal equilibrium within the telescope enclosure and reduce thermal gradients across the primary mirror surface. As a precursor to the fabrication of the seven mirror support systems, a full-scale prototype has also been built to validate design decisions and demonstrate the performance. In April 2023, OHB Italia S.p.A. finished manufacturing and testing the first of seven mirror covers for

3531-585: 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

3638-631: The Milky Way , the nearest supermassive black hole ( Sagittarius A* ), the nearest star to the Sun ( Proxima Centauri ), the Magellanic Clouds , and numerous nearby galaxies and exoplanets. The Giant Magellan Telescope’s Gregorian design will produce the highest possible image resolution of the universe over the widest field of view with only two light collecting surfaces, making it the most optically proficient of all extremely large telescopes in

3745-495: The Ohara Corporation of Japan and takes about 12–13 weeks. After being cast, they need to cool for about six months. Each takes approximately 4 years to cast and polish, obtaining a finish that is so smooth that the highest peaks and valleys are smaller than 1/1000 of the width of a human hair. As this was an off-axis segment, a wide array of new optical tests and laboratory infrastructure had to be developed to polish

3852-465: 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

3959-414: The 30-meter-class. Site preparation began with the first blast to level the mountain peak on March 23, 2012. In November 2015, construction was started at the site, with a ground-breaking ceremony. In January 2018, WSP was awarded the contract to manage construction of the Giant Magellan Telescope. The casting of the first mirror, in a rotating furnace , was completed on November 3, 2005. A third segment

4066-693: 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

4173-584: 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

4280-608: 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

4387-416: The GMT facility Adaptive Optics System. Science drivers for the Giant Magellan Telescope include studying planets in the habitable zones of their parent star in the search for life; the nature of dark matter, dark energy, gravity, and many other aspects of fundamental physics; the formation and evolution of the first stars and galaxies; and how black holes and galaxies co-evolve. The Giant Magellan Telescope

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4494-469: The Giant Magellan. In just over two minutes, the covers will retract in unison to protect the world’s largest mirrors when not in use. The telescope will use seven of the world's largest mirrors as primary mirror segments, each 8.417 m (27.61 ft) in diameter. These segments will then be arranged with one mirror in the center and the other six arranged symmetrically around it. The challenge

4601-561: 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

4708-515: 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

4815-425: 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

4922-725: 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

5029-526: 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

5136-415: 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

5243-697: The United States. The GMTO Corporation is a nonprofit 501(c)(3) organization with offices in Pasadena, California and Santiago, Chile. The organization has an established relationship with the Chilean government, having been recognized through a presidential decree as an “international organization” in Chile. The telescope operates under a cooperative agreement with the University of Chile, granting 10% of

5350-745: 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

5457-549: The atmospheric distortion of the light gathered by the telescope. The Adaptive Secondary Mirrors consist of a thin sheet of glass that is bonded to more than 7000 independently controlled voice coil actuators. Each segment can deform/reshape their 2-millimeter-thick surface 2,000 times per second to correct for the optical blurring effect of Earth’s atmosphere. The first segment is under construction as of August 2022 and will be completed in 2024. The Giant Magellan Telescope will have three modes of adaptive optics. The Giant Magellan

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5564-399: The back of the primary mirrors to correct for the effects of gravity and temperature variations on the seven, 8.4 meter diameter primary mirrors. In addition, fourteen air handler units using CO2 based refrigeration – the first system of its kind used for telescopes – are mounted to the interior of the mirror support system to circulate the air. A closed-cycle forced-air convection system

5671-618: 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

5778-498: 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

5885-573: 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

5992-588: The entire field with one or more of the spectrographs This enables the telescope to see fainter objects with unrivaled resolution and sensitivity. The advantage is extremely powerful for spectroscopy and the precise measurements of distances, dynamics, chemistry, and masses of celestial objects in deep space. Additionally the Commissioning Camera (ComCam) will be used to validate the Ground Layer Adaptive Optics performance of

6099-492: The existing WF/PC, included relay mirrors to direct light onto the four separate charge-coupled device (CCD) chips making up its two cameras. An inverse error built into their surfaces could completely cancel the aberration of the primary. However, the other instruments lacked any intermediate surfaces that could be configured in this way, and so required an external correction device. Pneumatic actuators A pneumatic control valve actuator converts energy (typically in

6206-501: 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

6313-465: 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,

6420-475: The form of compressed air ) into mechanical motion. The motion can be rotary or linear , depending on the type of actuator. A pneumatic actuator mainly consists of a piston or a diaphragm which develops the motive power. It keeps the air in the upper portion of the cylinder, allowing air pressure to force the diaphragm or piston to move the valve stem or rotate the valve control element. Valves require little pressure to operate and usually double or triple

6527-405: The input force. The larger the size of the piston, the larger the output pressure can be. Having a larger piston can also be good if the air supply is low, allowing the same forces with less input. These pressures are large enough to crush objects in the pipe. On 100 kPa input, you could lift a small car (upwards of 1,000 lbs) easily, and this is only a basic, small pneumatic valve. However,

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6634-467: 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

6741-413: 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

6848-425: The material flowing inside. The valve's input is the "control signal." This can come from a variety of measuring devices, and each different pressure is a different set point for a valve. A typical standard signal is 20–100 kPa. For example, a valve could be controlling the pressure in a vessel that has a constant out-flow, and a varied in-flow (varied by the actuator and valve). A pressure transmitter will monitor

6955-415: 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

7062-414: 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

7169-400: The mirror. The intention is to build seven identical off-axis mirrors, so that a spare is available to substitute for a segment being recoated, a 1–2 week (per segment) process required every 1–2 years. While the complete telescope will use seven mirrors, it is planned to begin operation with four mirrors. Segments 1–3 are complete. Segments 4–6 are undergoing polishing and testing. Segment 7

7276-427: 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

7383-499: 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

7490-452: 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

7597-547: The observing time to astronomers working at Chilean institutions. The following organizations are members of the consortium developing the telescope. The Giant Magellan Telescope is a part of the US Extremely Large Telescope Program (US-ELTP), as of 2018 . The US-ELTP will provide US-based astronomers with U.S. National Science Foundation funded all-sky observing access to both the Giant Magellan Telescope and Thirty Meter Telescope. The program

7704-666: 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

7811-411: 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

7918-416: The pressure in the vessel and transmit a signal from 20–100 kPa. 20 kPa means there is no pressure, 100 kPa means there is full range pressure (can be varied by the transmitters calibration points). As the pressure rises in the vessel, the output of the transmitter rises, this increase in pressure is sent to the valve, which causes the valve to stroke downward, and start closing the valve, decreasing flow into

8025-425: 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

8132-636: 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

8239-580: The resulting data, while the Goddard Space Flight Center (GSFC) controls 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

8346-402: The resulting forces required of the stem would be too great and cause the valve stem to fail. This pressure is transferred to the valve stem, which is connected to either the valve plug (see plug valve ), butterfly valve etc. Larger forces are required in high pressure or high flow pipelines to allow the valve to overcome these forces, and allow it to move the valves moving parts to control

8453-409: 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

8560-439: 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

8667-405: 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

8774-747: 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

8881-402: The strength comes from its unique shape and external shell. This allows the telescope mount to have a compact and lightweight design for its size. It also makes the telescope extremely stiff and stable so that it can resist image quality interruptions from wind and mechanical vibrations. The “cell” primary mirror support system contains “active optics” with pneumatic actuators that will push on

8988-468: 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,

9095-560: 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

9202-418: 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

9309-422: 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

9416-575: 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

9523-436: 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,

9630-501: 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

9737-436: 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

9844-455: 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

9951-409: 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

10058-535: 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

10165-466: The very large aperture and advanced adaptive optics. Image quality is projected at a 20 arcminute field of view, correctable from 0–20 arcminutes. The images will be sharp enough to resolve the torch engraved on a U.S. dime from nearly 160 kilometers (100 miles) away and expected to exceed that of the Hubble Space Telescope . The Carnegie Observatories office in Pasadena has an outline of the Giant Magellan primary mirror array painted in its parking lot. It

10272-406: 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

10379-403: The year. The sparse population in the surrounding Atacama Desert, combined with favorable geographical conditions, ensures minimal atmospheric and light pollution . This makes the area one of the best locations on Earth for long-term astronomical observation. The observatory's southern hemisphere location also provides access to significant astronomical targets, including the galactic center of

10486-413: Was awarded the contract to finalize the telescope’s enclosure design by 2024. The telescope mount structure is a 39 meters tall alt-azimuth design that will stand on a pier that is 22 meters in diameter. The structure will weigh 1,800 tons without mirrors and instruments. With mirrors and instruments, it will weigh 2,100 tons. This structure will float on a film of oil (50 microns thick), being supported by

10593-585: Was cast in August 2013, the fourth in September 2015, the fifth in 2017, the sixth in 2021, and the last in 2023. Polishing of the first mirror was completed in November 2012. Ingersoll Machine Tools finished constructing a manufacturing facility to manufacture the Giant Magellan Telescope mount in Rockford, Illinois in December 2021. As of 2022, construction of the telescope mount was underway. The structure

10700-534: 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

10807-480: 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

10914-529: 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

11021-402: Was in the manufacturing stage. Other subsystems of the telescope were in the final stages of design. The project, with an estimated cost of USD $ 2 billion, is being developed by the GMTO Corporation, a consortium of research institutions from seven countries: Australia, Brazil, Chile, Israel, South Korea, Taiwan, and the United States. The telescope is located at Las Campanas Observatory, which

11128-414: 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

11235-492: Was planned for casting in 2023. The primary mirror array will have a focal ratio (focal length divided by diameter) of f/0.71. For an individual segment – one third that diameter – this results in a focal ratio of f/2.14. The overall focal ratio of the complete telescope will be f/8 and the optical prescription is an aplanatic Gregorian telescope . Like all modern large telescopes it will make use of adaptive optics . Scientists expect very high quality images due to

11342-540: Was ranked as the highest ground-based priority in the National Academy of Sciences Astro2020 Decadal Survey which noted that the US-ELTP will provide “observational capabilities unmatched in space or the ground and open an enormous discovery space for new observations and discoveries not yet anticipated." Hubble Space Telescope The Hubble Space Telescope (often referred to as HST or Hubble )

11449-510: 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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