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71-559: The facility consists of a number of telescopes in domes and is similar to the US GEODSS system. It is designed for the detection and analysis of space objects such as satellites. The designers were awarded a Russian state prize for science and technology in 2004. The Okno facility was started by the Soviet Union in 1979 using thousands of military unit No. 14464 "Construction Forces" draftees. All construction stopped in 1992 due to

142-641: A catadioptric astrophotographic telescope designed to provide wide fields of view with limited aberrations . The design was invented by Bernhard Schmidt in 1930. Some notable examples are the Samuel Oschin telescope (formerly Palomar Schmidt), the UK Schmidt Telescope and the ESO Schmidt; these provided the major source of all-sky photographic imaging from 1950 until 2000, when electronic detectors took over. A recent example

213-602: A UHF (432 MHz) frequency. Although limited by their mechanical technology, Pirinclik's two radars gave the advantage of tracking two objects simultaneously in real time. Its location close to the southern Former Soviet Union made it the only ground sensor capable of tracking actual deorbits of Russian space objects. In addition, the Pirinclik radar was the only 24-hour-per-day eastern hemisphere deep space sensor. Radar operations at Pirinclik were terminated in March 1997. With

284-480: A basketball more than 20,000 miles (30,000 km) in space or a chair at 35,000 miles (56,000 km), and is a vital part of USSPACECOM's Space Surveillance Network. Each GEODSS site tracks approximately 3,000 objects per night out of 9,900 object that are regularly tracked and accounted for. Objects crossing the International Space Station (ISS) orbit within 20 miles (32 km) will cause

355-737: A database of satellite states since the launch of the first Sputnik in 1957, known as the Space Object Catalog, or simply the Space Catalog. These satellite states are regularly updated with observations from the Space Surveillance Network, a globally distributed network of interferometer, radar and optical tracking systems. By the year 2001, the number of cataloged objects was nearly 20,000. Different astrodynamics theories are used to maintain these catalogs. The General Perturbations (GP) theory provides

426-553: A design was used to construct a working 1/8-scale model of the Palomar Schmidt, with a 5° field. The retronym "lensless Schmidt" has been given to this configuration. Yrjö Väisälä originally designed an "astronomical camera" similar to Bernhard Schmidt's "Schmidt camera", but the design was unpublished. Väisälä did mention it in lecture notes in 1924 with a footnote: "problematic spherical focal plane". Once Väisälä saw Schmidt's publication, he promptly went ahead and solved

497-496: A general analytical solution of the satellite equations of motion. The orbital elements and their associated partial derivatives are expressed as series expansions in terms of the initial conditions of these differential equations . The GP theories operated efficiently on the earliest electronic computing machines, and were therefore adopted as the primary theory for Space Catalog orbit determination. Assumptions must be made to simplify these analytical theories, such as truncation of

568-632: A modification of the AN/FPS-80 tracking radar to the AN/FPS-80(M) configuration. Shemya, AK, 1964. Both of these systems incorporated GE M236 computers. A 60-foot dish mechanical tracking radar built by General Electric. Deployed at Shemya Island, Alaska, as a UHF radar and upgraded to L-Band in 1964. Used as tracker radar for Spacetrack network measurements once target detected. Principally used for intelligence purposes to track Russian missiles. The advanced FPS-108 Cobra Dane phased array radar replaced

639-509: A multiple axis mount allowing it to follow satellites in the sky – were used by the Smithsonian Astrophysical Observatory to track artificial satellites from June 1958 until the mid-1970s. The Mersenne–Schmidt camera consists of a concave paraboloidal primary mirror, a convex spherical secondary mirror, and a concave spherical tertiary mirror. The first two mirrors (a Mersenne configuration) perform

710-667: A primary mission of monitoring Soviet tests of missiles launched from southwest Russia aimed at the Siberian Kamchatka peninsula. This large, single-faced, phased-array radar was the most powerful ever built. The FPS-80 was a tracking radar and the FPS-17 was a detection radar for Soviet missiles. Both were part of the Ballistic Missile Early Warning System ( BMEWS ). The large detection radar (AN/FPS-17) went into operation in 1960. In 1961,

781-678: A spacetrack network. This spacetrack network, Project Shepherd, began with the Space Track Filter Center at Bedford, Massachusetts , and an operational space defense network (i.e., a missile warning network). ARDC took up the spacetrack mission in late 1959 and in April 1960 set up the Interim National Space Surveillance Control Center at Hanscom Field , Massachusetts , to coordinate observations and maintain satellite data. At

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852-411: A spherical primary mirror. Schmidt corrector plates work because they are aspheric lenses with spherical aberration that is equal to but opposite of the spherical primary mirrors they are placed in front of. They are placed at the center of curvature " C " of the mirrors for a pure Schmidt camera and just behind the prime focus for a Schmidt–Cassegrain . The Schmidt corrector is thicker in the middle and

923-434: A vacuum pan with the correct shape of the curve pre-shaped into the bottom of the pan, called a "master block". The upper exposed surface is then polished flat creating a corrector with the correct shape once the vacuum is released. This removes the need to have to hold a shape by applying an exact vacuum and allows for the mass production of corrector plates of the same exact shape. The technical difficulties associated with

994-742: Is also a Schmidt camera. The Schmidt telescope of the Karl Schwarzschild Observatory is the largest Schmidt camera of the world. A Schmidt telescope was at the heart of the Hipparcos (1989–1993) satellite from the European Space Agency . This was used in the Hipparcos Survey which mapped the distances of more than a million stars with unprecedented accuracy: it included 99% of all stars up to magnitude 11. The spherical mirror used in this telescope

1065-776: Is an Image Information Processing Center and Supercomputing facility at the Air Force Maui Optical Station (AMOS). The first formalized effort by the US government to catalog satellites occurred at Project Space Track, later known as the National Space Surveillance Control Center (NSSCC), located at Hanscom Field in Bedford, Massachusetts . The procedures used at the NSSCC were first reported in 1959 and 1960 by Wahl, who

1136-430: Is an optical system that uses telescopes , low-light level TV cameras, and computers. It replaced an older system of six 20 inch (half meter) Baker-Nunn cameras which used photographic film . There are three operational GEODSS sites that report to the 20th Space Control Squadron : A site at Choe Jong San, South Korea was closed in 1993 due to nearby smog from the town, weather and cost concerns. Originally,

1207-531: Is developing the kind of technology that would eventually be able to do so." Okno is a facility for tracking and monitoring man-made space objects. The Russian military claims that it automatically detects objects at altitudes up to 40,000 kilometres (25,000 mi). This is above low Earth orbit and includes satellites in medium Earth orbit , geostationary orbit and some in high Earth orbit . It only works at night and works passively by picking up reflected sunlight off objects. After 2014 modernization its range

1278-557: Is essential to computing the collision avoidance information to de-conflict launch windows with known orbiting space objects. The 21st Space Wing closed the Air Force Space Surveillance System on 1 October 2013 citing resource constraints caused by sequestration . A new S-band Space Fence is under construction at Kwajalein Atoll . The United States Department of Defense (DoD) has maintained

1349-429: Is mechanically conformed to the shape of the focal plane through the use of retaining clips or bolts, or by the application of a vacuum . A field flattener , in its simplest form a planoconvex lens in front of the film plate or detector, is sometimes used. Since the corrector plate is at the center of curvature of the primary mirror in this design the tube length can be very long for a wide-field telescope. There are also

1420-399: Is merited. Among these were two Trinidad detection and tracking radars; Laredo, Texas ; and Moorestown, New Jersey . Additional sensors that performed or contributed to space tracking but are not yet included in this page include mechanical tracking radars on the islands of Kaena Point , Antigua , Ascension Island , Naval Station San Miguel , and Kwajalein Atoll ; the three BMEWS sites;

1491-496: Is rarely used today. Holding the shape by constant vacuum is difficult and errors in the o-ring seal and even contamination behind the plate could induce optical errors. The glass plate could also break if bent enough to generate a curve for telescopes of focal ratio f/2.5 or faster. Also, for fast focal ratios, the curve obtained is not sufficiently exact and requires additional hand correction. A third method, invented in 1970 for Celestron by Tom Johnson and John O'rourke, uses

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1562-510: Is the Kepler space telescope exoplanet finder. Other related designs are the Wright camera and Lurie–Houghton telescope . The Schmidt camera was invented by Estonian-German optician Bernhard Schmidt in 1930. Its optical components are an easy-to-make spherical primary mirror , and an aspherical correcting lens , known as a Schmidt corrector plate , located at the center of curvature of

1633-463: The Aleutians . The original FPS-79 antenna at Diyarbakir had a unique feature which enhanced its Spacetrack usefulness. A variable-focus feed horn provided a wide beam for detection and a narrow beamwidth for tracking. That antenna was replaced by a new antenna and pedestal in 1975. Pulse compression was used to improve both the gain and resolution of the 35-foot (11 m) dish antenna. Steering

1704-482: The Operation Moonwatch program. Individuals at these Moonwatch sites recorded observations of satellites by visual means, but there were numerous observation types and sources, some automated, some only semi-automated. The observations were transferred to the NSSCC by teletype, telephone, mail, and personal messenger. There, a duty analyst reduced the data and determined corrections that should be made to

1775-587: The Pave Paws sites; the AN/FSS-7 missile warning radar sites; the Passive electronically scanned array sites; Cavalier, ND ; Eglin, FL ; Maui Space Surveillance System ; Globus II ; San Vito dei Normanni Air Station ; TOS/CROSS; and MIT Lincoln Laboratory . The Air Force Space Surveillance System (AFSSS), also known as the "space fence", was a very high frequency radar network located at sites across

1846-648: The Schmidt or Schmidt–Cassegrain telescope designs. It was invented by Bernhard Schmidt in 1931, although it may have been independently invented by Finnish astronomer Yrjö Väisälä in 1924 (sometimes called the Schmidt–Väisälä camera as a result). Schmidt originally introduced it as part of a wide-field photographic catadioptric telescope , the Schmidt camera. It is now used in several other telescope designs, camera lenses and image projection systems that utilise

1917-701: The Soviet Union led to a US government perceived need to better track objects in space using the Space Tracking System. The first US system, Minitrack , was already in existence at the time of the Sputnik launch, but the US quickly discovered that Minitrack could not reliably detect and track satellites. The US Navy designed Minitrack to track the Vanguard satellite, and so long as satellites followed

1988-579: The VHF band, sending out pulses at frequencies between approximately 180 to 220 MHz. The FPS-17 was unique in that, unlike most radar types, each site's version differed from the other sites. Differences included transmitter equipment, reflector size and number, and the number and arrangement of feed horns. Additionally, the FPS-17 was the first operational radar system to employ pulse compression techniques. There were two AN/FPS-17 antennas at Diyarbakir , Turkey, one antenna at Laredo, and three at Shemya in

2059-479: The civil war in Tajikistan and the centre started test operations in 1999 and combat duty in 2004. Ownership of the complex was transferred from Tajikistan to Russia in 2004 in return for the writing off of $ 242 million USD of Tajikistan's US$ 299 million debt to Russia. A Russian-operated space surveillance system located in Tajikistan, Okno-M, has reached its full capacity, making it four times more powerful,

2130-471: The AN/FPS-80 tracking radar was constructed nearby. These radars were closed in the 1970s. The Diyarbakır Air Station intelligence collection radar site ultimately consisted of one detection radar (FPS-17) and one mechanical tracking radar (FPS-79). The Pirinclik radars were operated by the 19th Surveillance Squadron . The FPS-17 radar reached IOC on 1 June 1955 and the FPS-79 in 1964. Both radars operated at

2201-644: The Air Force ran five sites, the Royal Canadian Air Force ran two, and the Smithsonian Institution's Astrophysics Observatory operated a further eight sites. The Baker-Nunn system, like Minitrack, provided little real-time data and was additionally limited to night-time, clear weather operations. Beyond the problems in acquiring data on satellites, it became obvious that the US tracking network would soon be overwhelmed by

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2272-661: The Earth's gravitational potential to a few zonal harmonic terms. The atmosphere is usually modeled as a static, spherical density field that exponentially decays . Third body influences and resonance effects are partially modeled. Increased accuracy of GP theory usually requires significant development efforts. NASA maintains civilian databases of GP orbital elements, also known as NASA or NORAD two-line elements . The GP element sets are "mean" element sets that have specific periodic features removed to enhance long-term prediction performance, and require special software to reconstruct

2343-489: The Earth. The SSN typically tracks space objects which are 10 centimeters in diameter (baseball size) or larger. The Space Surveillance Network has numerous sensors that provide data. They are separated in three categories: dedicated sensors, collateral sensors and auxiliary sensors. Both the dedicated and collateral sensors are operated by the USSPACECOM , but while the former have a primary objective to acquire SSN data,

2414-569: The FPS-17 and FPS-80 radars in 1977. The command accomplishes these tasks through its Space Surveillance Network (SSN) of U.S. Army, Navy and Space Force operated, 30+ ground-based radars and optical telescopes worldwide, plus 6 satellites in orbit. As of June 23, 2019 , the catalog built using SSN data listed 44,336 objects including 8,558 satellites launched into orbit since 1957. 17,480 of them were actively tracked while 1,335 were lost. The rest have re-entered Earth's turbulent atmosphere and disintegrated, or survived re-entry and impacted

2485-696: The ISS to adjust their orbit to avoid collision. The oldest object tracked is Object #4 ( Vanguard 1 ) launched in 1958. The SSN included one spaceborne sensor, the space-based visible (SBV) sensor, carried into orbit aboard the Midcourse Space Experiment ( MSX ) satellite launched by the Ballistic Missile Defense Organization in 1996. It was retired from service on June 2, 2008. The Space Based Space Surveillance ( SBSS ) pathfinder satellite now performs

2556-726: The Laredo installation in February 1956, and Shemya in May 1960. The first two installations closed without replacements; the Shemya installation was replaced by the Cobra Dane (AN/FPS-108) radar. The FPS-17 antenna featured a fixed parabolic torus section reflector that typically stood 175 feet (53 m) high and 110 feet (34 m) wide and was illuminated by an array of radar feed horns placed in front of it. The transmitters operated in

2627-492: The NSSS) reached initial operating capability in 1961. The role of the "fence" grew. The system detected space objects from new launches, maneuvers of existing objects, breakups of existing objects, and provided data to users from its catalog of space objects. Orbital parameters of more than 10,000 objects were maintained in this catalog—which has now gained usage by NASA, weather agencies, and friendly foreign agencies. The information

2698-640: The Russian Ministry of Defense reports in July 2015. The surveillance station successfully underwent state tests late in 2014. When it was built it was believed by some in the west to be a military anti-satellite laser facility rather than one for optical tracking. In 1987 John E. Pike of the Federation of American Scientists was quoted as saying " Whether or not this facility will be capable of shooting down satellites or 'Star Wars,' it most certainly

2769-650: The Soviet Union apparently making rapid progress in its rocket program, in 1954 the United States began a program to develop a long range surveillance radar. General Electric Heavy Military Electronics Division (HMED) in Syracuse, NY was the prime contractor and Lincoln Laboratory was a subcontractor. This detection radar, the AN/FPS-17 , was conceived, designed, built, and installed for operation in nine months. The first installation, designated AN/FPS-17(XW-1)

2840-727: The Space Surveillance Center (SSC) at the Cheyenne Mountain Complex in Colorado Springs, Colorado reported that the U.S. FPS-79 radar at Pirinclik, Turkey, noticed the debris within minutes of the fragmentation. Blue Nine refers to a project which produced the AN/FPS-79 Tracking Radar Set built by General Electric, used with the 466L Electromagnetic Intelligence System (ELINT); US Air Force. Blue Fox refers to

2911-723: The UK Science Research Council with a 1.2 meter Schmidt telescope at Siding Spring Observatory engaged in a collaborative sky survey to complement the first Palomar Sky Survey, but focusing on the southern hemisphere. The technical improvements developed during this survey encouraged the development of the Second Palomar Observatory Sky Survey (POSS II). The telescope used in the Lowell Observatory Near-Earth-Object Search (LONEOS)

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2982-715: The compressed trajectory . AN/FPS-17 and AN/FPS-80 radars were placed at Shemya Island in the Aleutian Islands off the Alaskan coast in the 1960s to track Soviet missile tests and to support the Air Force Spacetrack System. In July 1973, Raytheon won a contract to build a system called " Cobra Dane " on Shemya. Designated as the AN/FPS-108, Cobra Dane replaced AN/FPS-17 and AN/FPS-80 radars. Becoming operational in 1977, Cobra Dane also had

3053-453: The corrector by grinding and polishing the aspherical shape into a flat glass blank using specially shaped and sized tools. This method requires a high degree of skill and training on the part of the optical engineer creating the corrector. Schmidt himself worked out a second, more elegant, scheme for producing the complex figure needed for the correcting plate. A thin glass disk with a perfectly polished accurate flat surface on both sides

3124-419: The drawbacks of having the obstruction of the film holder or detector mounted at the focus halfway up the tube assembly, a small amount of light is blocked and there is a loss in contrast in the image due to diffraction effects of the obstruction and its support structure. A Schmidt corrector plate is an aspheric lens which corrects the spherical aberration introduced by the spherical primary mirror of

3195-451: The edge. This corrects the light paths so light reflected from the outer part of the mirror and light reflected from the inner portion of the mirror is brought to the same common focus " F ". The Schmidt corrector only corrects for spherical aberration. It does not change the focal length of the system. Schmidt corrector plates can be manufactured in many ways. The most basic method, called the "classical approach", involves directly figuring

3266-404: The field-flattening problem in Schmidt's design by placing a doubly convex lens slightly in front of the film holder. This resulting system is known as: Schmidt–Väisälä camera or sometimes as Väisälä camera . In 1940, James Baker of Harvard University modified the Schmidt camera design to include a convex secondary mirror, which reflected light back toward the primary. The photographic plate

3337-681: The fifth GEODSS was planned to be operated from a site in Portugal , but this was never built. Moron Optical Space Surveillance (MOSS), a transportable 22-inch aperture telescope that contributed to the GEODSS system was operational at Morón Air Base, Spain 37°10′12″N 5°36′32″W  /  37.170°N 5.609°W  / 37.170; -5.609 from 1997 to 2012. GEODSS tracks objects in deep space , or from about 3,000 mi (4,800 km) out to beyond geosynchronous altitudes. GEODSS requires nighttime and clear weather tracking because of

3408-481: The increasing diversity in launch trajectories, non-standard orbits, and geosynchronous altitudes, necessitates continued modernization of the SSN to meet existing and future requirements and ensure their cost-effective supportability. SPACETRACK also developed the systems interfaces necessary for the command and control, targeting, and damage assessment of a potential future U.S. anti-satellite weapon (ASAT) system. There

3479-548: The inherent limitations of an optical system. Each site has three telescopes. The telescopes have a 40-inch (1.02 m) aperture and a two-degree field of view. The telescopes are able to "see" objects 10,000 times dimmer than the human eye can detect. This sensitivity, and sky background during daytime that masks satellites reflected light, dictates that the system operate at night. As with any ground-based optical system, cloud cover and local weather conditions directly influence its effectiveness. GEODSS system can track objects as small as

3550-732: The international agreement on satellite transmitting frequencies, Minitrack could track any satellite. However, the Soviets chose not to use the international satellite frequencies. Thus, a major limitation of this system became visible. Minitrack could not detect or track an uncooperative or passive satellite. Concurrent with Minitrack was the use of the Baker-Nunn satellite tracking cameras . These systems used modified Schmidt telescopes of great resolution to photograph and identify objects in space. The cameras first became operational in 1958 and eventually operated at sites worldwide. At their peak,

3621-491: The latter obtain SSN data as a secondary objective. The auxiliary sensors are not operated by the USSPACECOM and usually perform space surveillance collaterally. Additionally sensors are classified as Near-Earth (NE) tracking - observing satellites, space debris and other objects in lower orbits, or Deep Space (DS) - generally for asteroids and comets . Ground-based Electro-Optical Deep Space Surveillance , or GEODSS ,

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3692-509: The mission previously handled by the MSX SBV. The Canadian military satellite Sapphire , launched in 2013, also contributes data to the SSN. The USSPACECOM is primarily interested in the active satellites, but also tracks space debris . As the number of space debris and the value of satellites in space grew it has become important to protect civil economic activity and help satellite operators avoid collisions with debris. In 2010, USSTRATCOM

3763-459: The object. Starting in the early 1970s, Celestron marketed an 8-inch Schmidt camera. The camera was focused in the factory and was made of materials with low expansion coefficients so it would never need to be focused in the field. Early models required the photographer to cut and develop individual frames of 35 mm film, as the film holder could only hold one frame of film. About 300 Celestron Schmidt cameras were produced. The Schmidt system

3834-502: The orbital elements before they were used for further predictions. After this analysis, the corrections were fed into an IBM 709 computer that computed the updated orbital data. The updated orbital data were then used in another phase of the same computer program to yield the geocentric ephemeris . From the geocentric ephemeris, three different products were computed and sent back to the observing stations for their planning of future observing opportunities. The launch of Sputnik 1 by

3905-406: The pan until a particular negative pressure had been achieved. This caused the glass plate to warp slightly. The exposed upper surface of the glass was then ground and polished spherical. When the vacuum was released, the lower surface of the plate returned to its original flat form while the upper surface had the aspheric figure needed for a Schmidt corrector plate. Schmidt's vacuum figuring method

3976-405: The primary mirror. The film or other detector is placed inside the camera, at the prime focus. The design is noted for allowing very fast focal ratios , while controlling coma and astigmatism . Schmidt cameras have very strongly curved focal planes , thus requiring that the film, plate, or other detector be correspondingly curved. In some cases the detector is made curved; in others flat media

4047-834: The production of Schmidt corrector plates led some designers, such as Dmitri Dmitrievich Maksutov and Albert Bouwers , to come up with alternative designs using more conventional meniscus corrector lenses. Because of its wide field of view, the Schmidt camera is typically used as a survey instrument, for research programs in which a large amount of sky must be covered. These include astronomical surveys , comet and asteroid searches, and nova patrols. In addition, Schmidt cameras and derivative designs are frequently used for tracking artificial Earth satellites . The first relatively large Schmidt telescopes were built at Hamburg Observatory and Palomar Observatory shortly before World War II . Between 1945 and 1980, about eight more large (1 meter or larger) Schmidt telescopes were built around

4118-463: The same function of the correcting plate of the conventional Schmidt. This form was invented by Paul in 1935. A later paper by Baker introduced the Paul-Baker design, a similar configuration but with a flat focal plane. The addition of a flat secondary mirror at 45° to the optical axis of the Schmidt design creates a Schmidt–Newtonian telescope . The addition of a convex secondary mirror to

4189-644: The same time, DOD designated the Aerospace Defense Command (ADCOM), formerly Air Defense Command, as the prime user of spacetrack data. ADCOM formulated the first US plans for space surveillance. During the years that intercontinental ballistic missiles were developing as frontline weapon systems, numerous missile detection and warning sensors were being experimented with and fielded as operational sensors and most of these contributed satellite observation data at one time or another. Many have been overlooked by current histories and additional research

4260-676: The southern United States (from California to Georgia ) with a centralized data processing site at the Naval Network and Space Operations Command in Dahlgren, Virginia . AFSSS began as the Navy's Space Surveillance (SPASUR) system in 1961 (later renamed NAVSPASUR). It was transferred to the Air Force in 2004 and renamed AFSSS. The "fence" was operated by the U.S. Air Force ( 20th Space Control Squadron Detachment 1). The Satellite Detection and Reconnaissance Defense (the former designation of

4331-410: The tremendous number of satellites that followed Sputnik and Vanguard. The amount of satellite tracking data accumulated required creation or expansion of organizations and equipment to sift through and catalog the objects. The need for real-time detection and tracking information to deal with Soviet satellite launches led on 19 December 1958 to ARPA's implementation of Executive Order 50-59 to establish

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4402-699: The world. One particularly famous and productive Schmidt camera is the Oschin Schmidt Telescope at Palomar Observatory , completed in 1948. This instrument was used in the National Geographic Society – Palomar Observatory Sky Survey (POSS, 1958), the POSS-II survey, the Palomar-Leiden (asteroid) Surveys, and other projects. The European Southern Observatory with a 1-meter Schmidt telescope at La Silla and

4473-567: Was at Diyarbakir ( Pirinclik ), Turkey, to detect Soviet launches. A second system, designated AN/FPS-17(XW-2), was installed at Laredo AFS (about 7 miles (11 km) northeast of Laredo AFB ) in Texas, to track rockets launched from White Sands, New Mexico , and serve as a radar test bed. A third system, designated AN/FPS-17(XW-3), was installed on Shemya Island, Alaska, to detect Soviet launches. The Diyarbakir FPS-17 became operational in June 1955,

4544-525: Was extremely accurate; if scaled up to the size of the Atlantic Ocean , bumps on its surface would be about 10 cm high. The Kepler photometer , mounted on NASA's Kepler space telescope (2009–2018), is the largest Schmidt camera launched into space. In 1977 at Yerkes Observatory , a small Schmidt telescope was used to derive an accurate optical position for the planetary nebula NGC 7027 to allow comparison between photographs and radio maps of

4615-401: Was given authority to provide SSA (Space Situational Awareness) services to commercial and foreign actors. As of 2019 the following services are provided: positional data of all tracked objects, conjunction assessment, disposal/end-of-life support and more through the space-track.org website. Schmidt camera#Baker-Nunn A Schmidt camera , also referred to as the Schmidt telescope , is

4686-852: Was increased to 50,000 km. GEODSS The United States Space Surveillance Network (SSN) detects, tracks, catalogs and identifies artificial objects orbiting Earth , e.g. active/inactive satellites , spent rocket bodies, or fragmentation debris . The system is the responsibility of United States Space Command and operated by the United States Space Force and its functions are: The Space Surveillance Network includes dedicated, collateral, and contributing electro-optical, passive radio frequency (RF) and radar sensors. It provides space object cataloging and identification, satellite attack warning, timely notification to U.S. forces of satellite fly-over, space treaty monitoring, and scientific and technical intelligence gathering. The continued increase in satellite and orbital debris populations, as well as

4757-471: Was mechanical; the FPS-79 had a range of 24,000 miles (39,000 km). The radar site closed in 1997. After circling the Earth in an apparently dormant state for 9 months, on November 13, 1986 the SPOT 1 Ariane third stage violently separated into some 465 detectable fragments - the most severe satellite breakup yet recorded prior to 2007. Although the debris cloud did not pass over the continental United States until more than 8 hours later, personnel in

4828-406: Was placed on a heavy rigid metal pan. The top surface of the pan around the edge of the glass disk was ground at a precise angle or bevel based on the coefficient of elasticity of the particular type of glass that was being used. The glass plate was sealed to the ground edge of the pan. Then a vacuum pump was used to exhaust the air between the pan and glass through a small hole in the center of

4899-424: Was popular, used in reverse, for television projection systems, notably the Advent design by Henry Kloss . Large Schmidt projectors were used in theaters, but systems as small as 8 inches were made for home use and other small venues. In the 1930s, Schmidt noted that the corrector plate could be replaced with a simple aperture at the mirror's center of curvature for a slow (numerically high f-ratio) camera. Such

4970-456: Was the technical director of the NSSCC. In 1960, under Project Space Track, Fitzpatrick and Findley developed detailed documentation of the procedures used at the NSSCC. Project Space Track began its history of satellite tracking from 1957–1961. Early Space Track observations of satellites were collected at more than 150 individual sites, including radar stations, Baker–Nunn cameras , telescopes, radio receivers, and by citizens participating in

5041-464: Was then installed near the primary, facing the sky. This variant is called the Baker-Schmidt camera. The Baker–Nunn design, by Baker and Joseph Nunn , replaces the Baker-Schmidt camera's corrector plate with a small triplet corrector lens closer to the focus of the camera. It used a 55 mm wide film derived from the Cinemascope 55 motion picture process. A dozen f/0.75 Baker-Nunn cameras with 20-inch apertures – each weighing 3.5 tons including

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