Misplaced Pages

Space Power Facility

Article snapshot taken from Wikipedia with creative commons attribution-sharealike license. Give it a read and then ask your questions in the chat. We can research this topic together.

Space Power Facility ( SPF ) is a NASA facility used to test spaceflight hardware under simulated launch and spaceflight conditions. The SPF is part of NASA's Neil A. Armstrong Test Facility, which in turn is part of the Glenn Research Center . The Neil A. Armstrong Test Facility and the SPF are located near Sandusky, Ohio ( Oxford Township, Erie County, Ohio ).

#566433

68-458: The SPF is able to simulate a spacecraft's launch environment, as well as in-space environments. NASA has developed these capabilities under one roof to optimize testing of spaceflight hardware while minimizing transportation issues. Space Power Facility has become a "One Stop Shop" to qualify flight hardware for crewed space flight. This facility provides the capability to perform the following environmental testing: The Space Power Facility ( SPF )

136-526: A metrology agency, the Bureau of Standards was directed by Herbert Hoover to set up divisions to develop commercial standards for materials and products. Some of these standards were for products intended for government use, but product standards also affected private-sector consumption. Quality standards were developed for products including some types of clothing, automobile brake systems and headlamps, antifreeze , and electrical safety. During World War I ,

204-476: A neutron science user facility: the NIST Center for Neutron Research (NCNR). The NCNR provides scientists access to a variety of neutron scattering instruments, which they use in many research fields (materials science, fuel cells, biotechnology, etc.). The SURF III Synchrotron Ultraviolet Radiation Facility is a source of synchrotron radiation , in continuous operation since 1961. SURF III now serves as

272-414: A variable geometry cryogenic cold shroud. The facility is available on a full-cost reimbursable basis to government, universities, and the private sector. The Aluminum Test Chamber is a vacuum-tight aluminum plate vessel that is 100 feet (30 m) in diameter and 122 feet (37 m) high. Designed for an external pressure of 2.5 psi (17 kPa) and internal pressure of 5 psi (34 kPa),

340-582: A NIST team as part of a DARPA competition. In September 2013, both The Guardian and The New York Times reported that NIST allowed the National Security Agency (NSA) to insert a cryptographically secure pseudorandom number generator called Dual EC DRBG into NIST standard SP 800-90 that had a kleptographic backdoor that the NSA can use to covertly predict the future outputs of this pseudorandom number generator thereby allowing

408-694: A combination of vacuum tubes and solid-state diode logic. About the same time the Standards Western Automatic Computer , was built at the Los Angeles office of the NBS by Harry Huskey and used for research there. A mobile version, DYSEAC , was built for the Signal Corps in 1954. Due to a changing mission, the "National Bureau of Standards" became the "National Institute of Standards and Technology" in 1988. Following

476-488: A draft of the CSF 2.0 for public comment through November 4, 2023. NIST decided to update the framework to make it more applicable to small and medium size enterprises that use the framework, as well as to accommodate the constantly changing nature of cybersecurity. In August 2024, NIST released a final set of encryption tools designed to withstand the attack of a quantum computer. These post-quantum encryption standards secure

544-539: A program to provide metrology services for United States scientific and commercial users. A laboratory site was constructed in Washington, DC , and instruments were acquired from the national physical laboratories of Europe. In addition to weights and measures, the Bureau developed instruments for electrical units and for measurement of light. In 1905 a meeting was called that would be the first "National Conference on Weights and Measures". Initially conceived as purely

612-644: A user-accessible cleanroom nanomanufacturing facility. This "NanoFab" is equipped with tools for lithographic patterning and imaging (e.g., electron microscopes and atomic force microscopes ). NIST has seven standing committees: As part of its mission, NIST supplies industry, academia, government, and other users with over 1,300 Standard Reference Materials (SRMs). These artifacts are certified as having specific characteristics or component content, used as calibration standards for measuring equipment and procedures, quality control benchmarks for industrial processes, and experimental control samples. NIST publishes

680-548: A wide range of electronic information, from confidential email messages to e-commerce transactions that propel the modern economy. Four scientific researchers at NIST have been awarded Nobel Prizes for work in physics : William Daniel Phillips in 1997, Eric Allin Cornell in 2001, John Lewis Hall in 2005 and David Jeffrey Wineland in 2012, which is the largest number for any US government laboratory not accounting for ubiquitous government contracts to state institutions and

748-441: Is a vacuum chamber built by NASA in 1969. It stands 122 feet (37 m) high and 100 feet (30 m) in diameter, enclosing a bullet -shaped space. It is the world's largest thermal vacuum chamber. It was originally commissioned for nuclear-electric power studies under vacuum conditions, but was later decommissioned. It was subsequently recommissioned for use in testing spacecraft propulsion systems. Recent uses include testing

SECTION 10

#1732791198567

816-422: Is a 6 in (150 mm) thick steel floor on top of 19 ft (5.8 m) of concrete, that is tied to the earth using 50 ft (15 m) deep tensioned rock anchors. There were over 21,000,000 pounds (9,500 t) of rock anchors, and 6,000,000 pounds (2,700 t) of concrete used in the construction of the fixed-base modal test facility and mechanical vibration test facility. The SPF Facility layout

884-584: Is a rigid enclosure from which air and other gases are removed by a vacuum pump . This results in a low- pressure environment within the chamber, commonly referred to as a vacuum . A vacuum environment allows researchers to conduct physical experiments or to test mechanical devices which must operate in outer space (for example) or for processes such as vacuum drying or vacuum coating . Chambers are typically made of metals which may or may not shield applied external magnetic fields depending on wall thickness, frequency , resistivity , and permeability of

952-424: Is accomplished through use of 4 TEAM Corporation Horizontal Actuators. The horizontal actuators are used during Vertical testing to counteract cross axis forces and overturning moments. NASA's Space Power Facility Vibro-Acoustic Construction In addition to the sine vibe table, a fixed-base Modal floor sufficient for the 20 ft (6.1 m) diameter test article is available. The fixed based Modal Test Facility

1020-479: Is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical science laboratory programs that include nanoscale science and technology , engineering , information technology , neutron research, material measurement, and physical measurement. From 1901 to 1988, the agency

1088-534: Is ideal for performing multiple test programs. The facility has two large high bay areas adjacent to either side of the vacuum chamber. The advantage of having both areas available is that it allows for two complex tests to be prepared simultaneously. One test can be prepared in a high bay while another test is being conducted in the vacuum chamber. Large chamber doors provide access to the test chamber from either high bay. NASA's Space Power Facility Vibro-Acoustic Construction Vacuum chamber A vacuum chamber

1156-412: Is mixed according to the manufacturers directions. Since the material may expand 4–5 times under a vacuum, the mixing container must be large enough to hold a volume of four to five times the amount of the original material that is being vacuumed to allow for the expansion; if not, it will spill over the top of the container requiring clean-up that can be avoided. The material container is then placed into

1224-649: Is now the Handbook 44 since 1918 and began publication under the current name in 1949. The 2010 edition conforms to the concept of the primary use of the SI (metric) measurements recommended by the Omnibus Foreign Trade and Competitiveness Act of 1988 . NIST is developing government-wide identity document standards for federal employees and contractors to prevent unauthorized persons from gaining access to government buildings and computer systems. In 2002,

1292-417: Is only possible to achieve a vacuum on the mercury scale of 24.896 Hg. To keep the material air-free, it must be slowly poured in a high and narrow stream starting from the corner of the mold box, or mold, letting the material flow freely into the box or mold cavity. Usually, this method will not introduce any new bubbles into the vacuumed material. To ensure that the material is totally devoid of air bubbles,

1360-575: Is providing practical guidance and tools to better prepare facility owners, contractors, architects, engineers, emergency responders, and regulatory authorities to respond to future disasters. The investigation portion of the response plan was completed with the release of the final report on 7 World Trade Center on November 20, 2008. The final report on the WTC Towers—including 30 recommendations for improving building and occupant safety—was released on October 26, 2005. NIST works in conjunction with

1428-463: Is shut off and the vacuum chamber release valve is opened to equalize air pressure. The vacuum chamber is opened, the material is removed and is ready to pour into the mold. Though a maximum vacuum one can theoretically achieve at sea level is 29.921 inches of mercury (Hg,) this will vary significantly as altitude increases. For example, in Denver, Colorado , at one mile (1.6 km) above sea level, it

SECTION 20

#1732791198567

1496-443: Is the process of using vacuum to remove gases from compounds which become entrapped in the mixture when mixing the components." To assure a bubble-free mold when mixing resin and silicone rubbers and slower-setting harder resins, a vacuum chamber is required. A small vacuum chamber is needed for de-airing (eliminating air bubbles) for materials prior to their setting. The process is fairly straightforward. The casting or molding material

1564-575: The Biden administration began plans to create a U.S. AI Safety Institute within NIST to coordinate AI safety matters. According to The Washington Post , NIST is considered "notoriously underfunded and understaffed", which could present an obstacle to these efforts. NIST, known between 1901 and 1988 as the National Bureau of Standards (NBS), is a measurement standards laboratory , also known as

1632-525: The Constitution of the United States , ratified in 1789, granted these powers to the new Congress: "The Congress shall have power ... To coin money, regulate the value thereof, and of foreign coin, and fix the standard of weights and measures". In January 1790, President George Washington , in his first annual message to Congress , said, "Uniformity in the currency, weights, and measures of

1700-752: The Handbook 44 each year after the annual meeting of the National Conference on Weights and Measures (NCWM). Each edition is developed through cooperation of the Committee on Specifications and Tolerances of the NCWM and the Weights and Measures Division (WMD) of NIST. The purpose of the book is a partial fulfillment of the statutory responsibility for "cooperation with the states in securing uniformity of weights and measures laws and methods of inspection". NIST has been publishing various forms of what

1768-568: The National Construction Safety Team Act mandated NIST to conduct an investigation into the collapse of the World Trade Center buildings 1 and 2 and the 47-story 7 World Trade Center. The "World Trade Center Collapse Investigation", directed by lead investigator Shyam Sunder, covered three aspects, including a technical building and fire safety investigation to study the factors contributing to

1836-559: The National Medal of Science has been awarded to NIST researchers Cahn (1998) and Wineland (2007). Other notable people who have worked at NBS or NIST include: Since 1989, the director of NIST has been a Presidential appointee and is confirmed by the United States Senate , and since that year the average tenure of NIST directors has fallen from 11 years to 2 years in duration. Since the 2011 reorganization of NIST,

1904-737: The September 11, 2001 attacks, under the National Construction Safety Team Act (NCST), NIST conducted the official investigation into the collapse of the World Trade Center buildings. Following the 2021 Surfside condominium building collapse , NIST sent engineers to the site to investigate the cause of the collapse. In 2019, NIST launched a program named NIST on a Chip to decrease the size of instruments from lab machines to chip size. Applications include aircraft testing, communication with satellites for navigation purposes, and temperature and pressure. In 2023,

1972-870: The Technical Guidelines Development Committee of the Election Assistance Commission to develop the Voluntary Voting System Guidelines for voting machines and other election technology. In February 2014 NIST published the NIST Cybersecurity Framework that serves as voluntary guidance for organizations to manage and reduce cybersecurity risk. It was later amended and Version 1.1 was published in April 2018. Executive Order 13800, Strengthening

2040-842: The Treaty of the Meter , which established the International Bureau of Weights and Measures under the control of an international committee elected by the General Conference on Weights and Measures . NIST is headquartered in Gaithersburg, Maryland , and operates a facility in Boulder, Colorado , which was dedicated by President Eisenhower in 1954. NIST's activities are organized into laboratory programs and extramural programs. Effective October 1, 2010, NIST

2108-700: The proximity fuze and the standardized airframe used originally for Project Pigeon , and shortly afterwards the autonomously radar-guided Bat anti-ship guided bomb and the Kingfisher family of torpedo-carrying missiles. In 1948, financed by the United States Air Force, the Bureau began design and construction of SEAC , the Standards Eastern Automatic Computer. The computer went into operation in May 1950 using

Space Power Facility - Misplaced Pages Continue

2176-406: The Bureau worked on multiple problems related to war production, even operating its own facility to produce optical glass when European supplies were cut off. Between the wars, Harry Diamond of the Bureau developed a blind approach radio aircraft landing system. During World War II, military research and development was carried out, including development of radio propagation forecast methods,

2244-729: The Cybersecurity of Federal Networks and Critical Infrastructure , made the Framework mandatory for U.S. federal government agencies. An extension to the NIST Cybersecurity Framework is the Cybersecurity Maturity Model (CMMC) which was introduced in 2019 (though the origin of CMMC began with Executive Order 13556). It emphasizes the importance of implementing Zero-trust architecture (ZTA) which focuses on protecting resources over

2312-702: The EC-DRBG algorithm from the NIST SP 800-90 standard. In addition to these journals, NIST (and the National Bureau of Standards before it) has a robust technical reports publishing arm. NIST technical reports are published in several dozen series, which cover a wide range of topics, from computer technology to construction to aspects of standardization including weights, measures and reference data. In addition to technical reports, NIST scientists publish many journal and conference papers each year; an database of these, along with more recent technical reports, can be found on

2380-527: The Earth-launch thrust axis (X) at 5–150 Hz, 0-1.25 g-pk vertical, and 5–150 Hz 0-1.0 g-pk for the horizontal axes. Vertical, or the thrust axis, shaking is accomplished by using 16 vertical actuators manufactured by TEAM Corporation , each capable of 30,000 lbf (130 kN). The 16 vertical actuators allow for testing of up to a 75,000 lb (34,000 kg) article at the previously stated frequency and amplitude limits. Horizontal shaking

2448-536: The NIST cryptography process because of its recognized expertise. NIST is also required by statute to consult with the NSA." Recognizing the concerns expressed, the agency reopened the public comment period for the SP800-90 publications, promising that "if vulnerabilities are found in these or any other NIST standards, we will work with the cryptographic community to address them as quickly as possible". Due to public concern of this cryptovirology attack, NIST rescinded

2516-600: The National Metrological Institute (NMI), which is a non-regulatory agency of the United States Department of Commerce . The institute's official mission is to: Promote U.S. innovation and industrial competitiveness by advancing measurement science , standards , and technology in ways that enhance economic security and improve our quality of life . NIST had an operating budget for fiscal year 2007 (October 1, 2006 – September 30, 2007) of about $ 843.3 million. NIST's 2009 budget

2584-511: The US national standard for source-based radiometry throughout the generalized optical spectrum. All NASA -borne, extreme-ultraviolet observation instruments have been calibrated at SURF since the 1970s, and SURF is used for the measurement and characterization of systems for extreme ultraviolet lithography . The Center for Nanoscale Science and Technology (CNST) performs research in nanotechnology , both through internal research efforts and by running

2652-487: The United States is an object of great importance, and will, I am persuaded, be duly attended to." On October 25, 1791, Washington again appealed Congress: A uniformity of the weights and measures of the country is among the important objects submitted to you by the Constitution and if it can be derived from a standard at once invariable and universal, must be no less honorable to the public council than conducive to

2720-580: The airbag landing systems for the Mars Pathfinder and the Mars Exploration Rovers , Spirit and Opportunity, under simulated Mars atmospheric conditions. The facility was designed and constructed to test both nuclear and non-nuclear space hardware in a simulated Low-Earth-Orbiting environment. Although the facility was designed for testing nuclear hardware, only non-nuclear tests have been performed throughout its history. Some of

2788-588: The airbag landing systems for the Mars Pathfinder and the Mars Exploration Rovers , Spirit and Opportunity, under simulated Mars atmospheric conditions. Each arm of the LIGO detectors in Livingston , Louisiana , and Hanford , Washington , is a vacuum chamber 4 kilometres (2.5 mi) long, making them the longest vacuum chambers in the world. National Institute of Standards and Technology The National Institute of Standards and Technology ( NIST )

Space Power Facility - Misplaced Pages Continue

2856-557: The aluminum test chamber is pumped down to a pressure of 20 torrs (2.7 kPa) during a test. Brian Cox of the BBC's Human Universe filmed a rock and feather drop episode at the Space Power Facility. Below is a YouTube clip: Rock and Feather Drop at NASA's Space Power Facility Designed specifically as a large-scale thermal-vacuum test chamber for qualification testing of vehicles and equipment in outer-space conditions, it

2924-436: The chamber is constructed of Type 5083 aluminum which is a clad on the interior surface with a 1 ⁄ 8  in (3.2 mm) thick type 3003 aluminum for corrosion resistance. This material was selected because of its low neutron absorption cross-section. The floor plate and vertical shell are 1 inch (25 mm) (total) thick, while the dome shell is 1 + 3 ⁄ 8  in (35 mm). Welded circumferentially to

2992-402: The chamber was designed to withstand atmospheric pressure outside of the chamber at the same time vacuum conditions are occurring within. The concrete thickness varies from 6 to 8 feet (1.8 to 2.4 m) and contains a leak-tight steel containment barrier embedded within. The chamber's doors are 50 by 50 feet (15 by 15 m) and have inflatable seals. The space between the concrete enclosure and

3060-522: The country. NIST publishes the Handbook 44 that provides the "Specifications, tolerances, and other technical requirements for weighing and measuring devices". The Congress of 1866 made use of the metric system in commerce a legally protected activity through the passage of Metric Act of 1866 . On May 20, 1875, 17 out of 20 countries signed a document known as the Metric Convention or

3128-493: The director also holds the title of Under Secretary of Commerce for Standards and Technology. Fifteen individuals have officially held the position (in addition to four acting directors who have served on a temporary basis). NIST holds patents on behalf of the Federal government of the United States , with at least one of them being custodial to protect public domain use, such as one for a Chip-scale atomic clock , developed by

3196-474: The entire mold/mold box may be placed in the chamber for an additional few minutes; this will assist the material in flowing into difficult areas of the mold/mold box. Water and other liquids may accumulate on a product during the production process. "Vacuum is often employed as a process for removing bulk and absorbed water (or other solvents) from a product. Combined with heat, vacuum can be an effective method for drying." NASA 's Space Power Facility houses

3264-508: The exterior surface is aluminum structural T-section members that are 3 feet (0.9 m) deep and 2 feet (0.6 m) wide. The doors of the test chamber are 50 by 50 feet (15 by 15 m) in size and have double door seals to prevent leakage. The chamber floor was designed for a load of 300 tons. The concrete chamber enclosure serves not only as a radiological shield but also as a primary vacuum barrier from atmospheric pressure. 130 feet (40 m) in diameter and 150 feet (46 m) in height,

3332-483: The flange is bolted on. A type of vacuum chamber frequently used in the field of spacecraft engineering is a thermal vacuum chamber , which provides a thermal environment representing what a spacecraft would experience in space. Vacuum chambers can be constructed of many materials. "Metals are arguably the most prevalent vacuum chamber materials." The strength, pressure, and permeability are considerations for selecting chamber material. Common materials are: "Vacuum

3400-430: The high noise levels that will be experienced during a space vehicle launch and supersonic ascent conditions. The RATF is capable of an overall sound pressure level of 163 dB within a 101,500-cubic-foot (2,870 m) chamber. The Mechanical Vibration Test Facility (MVF), is a three-axis vibration system. It will apply vibration in each of the three orthogonal axes (not simultaneously) with one direction in parallel to

3468-416: The material used. Only some materials are suitable for vacuum use. Chambers often have multiple ports, covered with vacuum flanges , to allow instruments or windows to be installed in the walls of the chamber. In low to medium-vacuum applications, these are sealed with elastomer o-rings . In higher vacuum applications, the flanges have knife edges machined onto them, which cut into a copper gasket when

SECTION 50

#1732791198567

3536-409: The national physical laboratory for the United States. Southard had previously sponsored a bill for metric conversion of the United States. President Theodore Roosevelt appointed Samuel W. Stratton as the first director. The budget for the first year of operation was $ 40,000. The Bureau took custody of the copies of the kilogram and meter bars that were the standards for US measures, and set up

3604-429: The network perimeter. ZTA utilizes zero trust principles which include "never trust, always verify", "assume breach" and "least privileged access" to safeguard users, assets, and resources. Since ZTA holds no implicit trust to users within the network perimeter, authentication and authorization are performed at every stage of a digital transaction. This reduces the risk of unauthorized access to resources. NIST released

3672-547: The private sector. All four were recognized for their work related to laser cooling of atoms, which is directly related to the development and advancement of the atomic clock. In 2011, Dan Shechtman was awarded the Nobel Prize in chemistry for his work on quasicrystals in the Metallurgy Division from 1982 to 1984. In addition, John Werner Cahn was awarded the 2011 Kyoto Prize for Materials Science, and

3740-482: The probable cause of the collapses of the WTC Towers (WTC 1 and 2) and WTC 7. NIST also established a research and development program to provide the technical basis for improved building and fire codes, standards, and practices, and a dissemination and technical assistance program to engage leaders of the construction and building community in implementing proposed changes to practices, standards, and codes. NIST also

3808-481: The public convenience. In 1821, President John Quincy Adams declared, "Weights and measures may be ranked among the necessities of life to every individual of human society.". Nevertheless, it was not until 1838 that the United States government adopted a uniform set of standards. From 1830 until 1901, the role of overseeing weights and measures was carried out by the Office of Standard Weights and Measures, which

3876-482: The spring of 2017 the low-power characterizations and calibrations from 2009 and 2011 were proven correct in a series of high-power tests performed in the chamber to validate its capabilities. The SPF chamber is currently being prepared for EMI radiated susceptibility testing of the crew module for the Artemis 1 of NASA's Orion spacecraft . The Reverberant Acoustic Test Facility has 36 nitrogen-driven horns to simulate

3944-431: The standard by NSA). NIST responded to the allegations, stating that "NIST works to publish the strongest cryptographic standards possible" and that it uses "a transparent, public process to rigorously vet our recommended standards". The agency stated that "there has been some confusion about the standards development process and the role of different organizations in it...The National Security Agency (NSA) participates in

4012-415: The surreptitious decryption of data. Both papers report that the NSA worked covertly to get its own version of SP 800-90 approved for worldwide use in 2006. The whistle-blowing document states that "eventually, NSA became the sole editor". The reports confirm suspicions and technical grounds publicly raised by cryptographers in 2007 that the EC-DRBG could contain a kleptographic backdoor (perhaps placed in

4080-461: The test programs that have been performed at the facility include high-energy experiments, rocket-fairing separation tests, Mars Lander system tests, deployable Solar Sail tests and International Space Station hardware tests. The facility can sustain a high vacuum (10 torr , 130 μPa); simulate solar radiation via a 4 MW quartz heat lamp array, solar spectrum by a 400 kW arc lamp, and cold environments (−320 °F (−195.6 °C)) with

4148-403: The vacuum chamber; a vacuum pump is connected and turned on. Once the vacuum reaches 29 inches (at sea level) of mercury, the material will begin to rise (resembling foam ). When the material falls, it will plateau and stop rising. The vacuuming is continued for another 2 to 3 minutes to make certain all of the air has been removed from the material. Once this interval is reached, the vacuum pump

SECTION 60

#1732791198567

4216-399: The world's largest vacuum chamber. It was built in 1969 and stands 122 feet (37 m) high and 100 feet (30 m) in diameter, enclosing a bullet -shaped space. It was originally commissioned for nuclear-electric power studies under vacuum conditions, but was later decommissioned. Recently, it was recommissioned for use in testing spacecraft propulsion systems. Recent uses include testing

4284-523: Was $ 992 million, and it also received $ 610 million as part of the American Recovery and Reinvestment Act . NIST employs about 2,900 scientists, engineers, technicians, and support and administrative personnel. About 1,800 NIST associates (guest researchers and engineers from American companies and foreign countries) complement the staff. In addition, NIST partners with 1,400 manufacturing specialists and staff at nearly 350 affiliated centers around

4352-517: Was discovered in the late 2000s that the unique construction of the SPF interior aluminum vacuum chamber also makes it an extremely large and electrically complex microwave or radio frequency cavity with excellent reverberant electro-magnetic characteristics. In 2009 these characteristics were measured by the National Institute of Standards and Technology and others after which the facility

4420-553: Was named the National Bureau of Standards . The Articles of Confederation , ratified by the colonies in 1781, provided: The United States in Congress assembled shall also have the sole and exclusive right and power of regulating the alloy and value of coin struck by their own authority, or by that of the respective states—fixing the standards of weights and measures throughout the United States. Article 1, section 8, of

4488-719: Was part of the Survey of the Coast—renamed the United States Coast Survey in 1836 and the United States Coast and Geodetic Survey in 1878—in the United States Department of the Treasury . In 1901, in response to a bill proposed by Congressman James H. Southard (R, Ohio), the National Bureau of Standards was founded with the mandate to provide standard weights and measures, and to serve as

4556-619: Was realigned by reducing the number of NIST laboratory units from ten to six. NIST Laboratories include: Extramural programs include: NIST's Boulder laboratories are best known for NIST‑F1 , which houses an atomic clock . NIST‑F1 serves as the source of the nation's official time. From its measurement of the natural resonance frequency of cesium —which defines the second —NIST broadcasts time signals via longwave radio station WWVB near Fort Collins , Colorado, and shortwave radio stations WWV and WWVH , located near Fort Collins and Kekaha, Hawaii , respectively. NIST also operates

4624-551: Was understood to be, not only the world's largest Vacuum chamber, but also the world's largest EMI/EMC test facility. In 2011, the Glenn Research Center successfully performed a calibration of the aluminum vacuum chamber using IEC 61000-4-21 methodologies. As a result of these activities, the SPF is capable of performing radiated susceptibility EMI tests for vehicles and equipment per MIL-STD-461 and able to achieve MIL-STD-461F limits above approximately 80 MHz. In

#566433