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Student Nitric Oxide Explorer
Student Nitric Oxide Explorer (SNOE ("snowy"), also known as Explorer 72, STEDI-1 and UNEX-1), was a NASA small scientific satellite which studied the concentration of nitric oxide in the thermosphere. It was launched in 1998 as part of NASA's Explorer program. The satellite was the first of three missions developed within the Student Explorer Demonstration Initiative (STEDI) program funded by the NASA and managed by the Universities Space Research Association (USRA). STEDI was a pilot program to demonstrate that high-quality space science can be carried out with small, low-cost ( |
Space Physics
Space physics, also known as solar-terrestrial physics or space-plasma physics, is the study of plasmas as they occur naturally in the Earth's upper atmosphere (aeronomy) and within the Solar System. As such, it encompasses a far-ranging number of topics, such as heliophysics which includes the solar physics of the Sun, the solar wind, planetary magnetospheres and ionospheres, auroras, cosmic rays, and synchrotron radiation. Space physics is a fundamental part of the study of space weather and has important implications in not only to understanding the universe, but also for practical everyday life, including the operations of communications and weather satellites. Space physics is distinct from astrophysical plasma and the field of astrophysics, which studies similar plasma phenomena beyond the Solar System. Space physics utilizes in situ measurements from high altitude rockets and spacecraft, in contrast to astrophysical plasma that relies deduction of theory and astronomical obse ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Universities Space Research Association
The Universities Space Research Association (USRA) was incorporated on March 12, 1969, in Washington, D.C. as a private, nonprofit corporation under the auspices of the National Academy of Sciences (NAS). Institutional membership in the association currently stands at 113 universities. All member institutions have graduate programs in space sciences or technology. Besides the 98 member institutions in the United States, there are two member institutions in Canada, four in Europe, two in Israel, one in Australia and one in New Zealand, one in Hong Kong, two in Korea and two in the United Kingdom. Objective USRA provides a mechanism through which universities can cooperate effectively with one another, with the government, and with other organizations to further space science and technology, and to promote education in these areas. Its mission is carried out through the institutes, centers, divisions, and programs. Administrative and scientific personnel now number about 420. A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Teledesic
Teledesic was a company founded in the 1990s to build a commercial broadband satellite internet constellation. Using low-Earth-orbiting satellites small antennas could be used to provide uplinks of as much as 100 Mbit/s and downlinks of up to 720 Mbit/s. The original 1994 proposal was extremely ambitious, costing over 9 billion USD and originally planning 840 active satellites with in-orbit spares at an altitude of 700 km. In 1997, the plan was scaled back to 288 active satellites at 1400 km. Teledesic Corporation changed its name to Teledesic, LLC by pro forma assignment of its license, granted on 26 January 1998. The commercial failure of the similar Iridium and Globalstar ventures (composed of 66 and 48 operational satellites respectively) and other systems, along with bankruptcy protection filings, were primary factors in halting the project, and Teledesic officially suspended its satellite construction work on 1 October 2002. Description The Teledesic system would have provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Launch Vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch control center, launch control center and systems such as vehicle assembly and fueling. Launch vehicles are engineered with advanced aerodynamics and technologies, which contribute to large operating costs. An orbital spaceflight, orbital launch vehicle must lift its payload at least to the boundary of space, approximately and accelerate it to a horizontal velocity of at least . Suborbital spaceflight, Suborbital vehicles launch their payloads to lower velocity or are launched at elevation angles greater than horizontal. Practical orbital launch vehicles are multistage rockets which use chemical propellants such as Solid-propellant rocket, solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Cell
A solar cell, or photovoltaic cell, is an electronic device that converts the energy of light directly into electricity by the photovoltaic effect, which is a physical and chemical phenomenon.Solar Cells chemistryexplained.com It is a form of photoelectric cell, defined as a device whose electrical characteristics, such as , , or resistance, vary when exposed to light. Individual solar cell devices are often the electrical ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Revolutions Per Minute
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines. Standards ISO 80000-3:2019 defines a unit of rotation as the dimensionless unit equal to 1, which it refers to as a revolution, but does not define the revolution as a unit. It defines a unit of rotational frequency equal to s−1. The superseded standard ISO 80000-3:2006 did however state with reference to the unit name 'one', symbol '1', that "The special name revolution, symbol r, for this unit is widely used in specifications on rotating machines." The International System of Units (SI) does not recognize rpm as a unit, and defines the unit of frequency, Hz, as equal to s−1. :\begin 1~&\text &&=& 60~&\text \\ \frac~&\text &&=& 1~&\text \end A corresponding but distinct quantity for describing rotation is angular velocity, for which the SI unit is the ra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin-stabilisation
Spin stabilization is the method of stabilizing a satellite or launch vehicle by means of spin, i.e. rotation along the longitudinal axis. The concept originates from ballistics, where the spin is commonly obtain by means of rifling. For most satellite applications this approach has been superseded by three-axis stabilization. Despinning can be achieved by various techniques, including yo-yo de-spin. Use On rockets with a solid motor upper stage, spin stabilization is used to keep the motor from drifting off course as they don't have their own thrusters. Usually small rockets are used to spin up the spacecraft and rocket then fire the rocket and send the craft off. Some rockets, like the Jupiter-C, Delta II, Minotaur V and the satellite Aryabhata are spin-stabilised. The Pioneer 4 spacecraft, the second object sent on a lunar flyby in 1959, maintained its attitude using spin-stabilization. The Schiaparelli EDM lander was spun up to 2.5 RPM before being ejected from the ExoMar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Regions Of Earth
The polar regions, also called the frigid geographical zone, zones or polar zones, of Earth are the regions of the planet that surround its geographical poles (the North Pole, North and South Poles), lying within the polar circles. These high latitudes are dominated by floating Arctic ice pack, sea ice covering much of the Arctic Ocean in the north, and by the Antarctic ice sheet on the continent of Antarctica and the Southern Ocean in the south. Definitions The Arctic has various definitions, including the region north of the Arctic Circle (currently Epoch 2010 at 66°33'44" N), or just the region north of 60th parallel north, 60° north latitude, or the region from the North Pole north to the Tree line, timberline. The Antarctic is usually defined simply as south of 60th parallel south, 60° south latitude, or the continent of Antarctica. The 1959 Antarctic Treaty System, Antarctic Treaty uses the former definition. The two polar regions are distinguished from the other two c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Leicester
, mottoeng = So that they may have life , established = , type = public research university , endowment = £20.0 million , budget = £326 million , chancellor = David Willetts , vice_chancellor = Nishan Canagarajah , head_label = Visitor , head = The King , academic_staff = 1,705 (2018/19) , administrative_staff = 2,205 (2018/19) , students = () , undergrad = () , postgrad = () , city = Leicester , country = England, UK , coordinates = , campus = Urban parkland , colours = , website = , logo = UniOfLeicesterLogo.svg , logo_size = 250px , affiliations = ACUAMBA EMUA EUA Sutton 30 M5 UniversitiesUniversities UK The University of Leicester ( ) is a public research university based in Leicester, England. The main campus is south of the city centre, adjacent to Victoria Park. The university's predecessor, University College, Leicester, gained university status in 1957. The university had an income of £323.1 million in 2019/20, of which £5 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boston University
Boston University (BU) is a private research university in Boston, Massachusetts. The university is nonsectarian, but has a historical affiliation with the United Methodist Church. It was founded in 1839 by Methodists with its original campus in Newbury, Vermont, before moving to Boston in 1867. The university now has more than 4,000 faculty members and nearly 34,000 students, and is one of Boston's largest employers. It offers bachelor's degrees, master's degrees, doctorates, and medical, dental, business, and law degrees through 17 schools and colleges on three urban campuses. The main campus is situated along the Charles River in Boston's Fenway-Kenmore and Allston, Massachusetts, Allston neighborhoods, while the Boston University Medical Campus is located in Boston's South End, Boston, South End neighborhood. The Fenway campus houses the Wheelock College of Education and Human Development, formerly Wheelock College, which merged with BU in 2018. BU is a member of the Bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TERRIERS
Terrier (from Latin ''terra'', 'earth') is a type of dog originally bred to hunt vermin. A terrier is a dog of any one of many breeds or landraces of the terrier type, which are typically small, wiry, game, and fearless. Terrier breeds vary greatly in size from just to over 60 kg (132 lb, e.g. Black Russian Terrier) and are usually categorized by size or function. There are five different groups of terrier, with each group having different shapes and sizes. History Most terrier breeds were refined from the older purpose-bred dogs. The gameness of the early hunting terriers was exploited by using them in sporting contests. Initially, terriers competed in events such as clearing a pit of rats. The dog that was fastest in killing all the rats won. In the eighteenth century some terriers were crossed with hounds to improve their hunting, and some with fighting dog breeds to "intensify tenacity and increase courage". Some of the crosses with fighting dogs, bull and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
