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UPSat Testing
UPSat was the first satellite manufactured in Greece to be successfully launched into orbit, by the University of Patras and Libre Space Foundation (an earlier Greek-made communications satellite, HELMARS-SAT, although entirely constructed by 1999, was not launched due to budget limitations). It was part of the QB50 mission with ID GR-02. The UPSat mission was the first satellite launched into orbit made entirely of open-source software and open-source hardware. Open-source The UPSat mission developed an open-source hardware and software 2U cubesat, minimizing the use of commercial off the shelf components, and providing hardware and software designs under the provisions of the CERN-OHLv2 and GNU-GPLv3 licenses respectfully. The vast majority of its components were designed from scratch in an open-source software and hardware way. Mission UPSat, as part of the QB50 cubesat constellation, was launched to the International Space Station at April 18, 2017 11:11 EDT at Cape Canave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
QB50
A CubeSat is a class of small satellite with a form factor of cubes. CubeSats have a mass of no more than per unit,, url=https://static1.squarespace.com/static/5418c831e4b0fa4ecac1bacd/t/5f24997b6deea10cc52bb016/1596234122437/CDS+REV14+2020-07-31+DRAFT.pdf , title=Cubesat Design Specification , publisher= Cal Poly SLO , year=2020 , location=San Luis Obispo , pages=12 and often use commercial off-the-shelf (COTS) components for their electronics and structure. CubeSats are deployed into orbit from the International Space Station, or launched as secondary payloads on a launch vehicle. , more than 2,300 CubeSats have been launched. In 1999, California Polytechnic State University (Cal Poly) professor Jordi Puig-Suari and Bob Twiggs, a professor at Stanford University Space Systems Development Laboratory, developed the CubeSat specifications to promote and develop the skills necessary for the design, manufacture, and testing of small satellites intended for low Earth orbit (LEO) that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NanoRacks CubeSat Deployer
The Nanoracks CubeSat Deployer (NRCSD) is a device to deploy CubeSats into orbit from the International Space Station (ISS). In 2014, two CubeSat deployers were on board the International Space Station (ISS): the Japanese Experiment Module (JEM) Small Satellite Orbital Deployer (J-SSOD) and the Nanoracks CubeSat Deployer (NRCSD). The J-SSOD is the first of its kind to deploy small satellites from the International Space Station (ISS). The NRCSD is the first commercially operated small satellite deployer from the ISS, maximizing full capabilities of each airlock cycle of deployments. CubeSats belong to a class of research spacecraft called nanosatellites. The basic cube-shaped satellites measure on each side, weigh less than , and have a volume of about , although there are CubeSats which are built and deployed with sizes of multiples of 10 cm in length. , one method of getting CubeSats to orbit is to transport them aboard a larger spacecraft as part of a cargo load to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Oslo
The University of Oslo (; ) is a public university, public research university located in Oslo, Norway. It is the List of oldest universities in continuous operation#Europe, oldest university in Norway. Originally named the Royal Frederick University, the university was established in 1811 as the de facto Norwegian continuation of Denmark-Norway's common university, the University of Copenhagen, with which it shares many traditions. It was named for King Frederick VI of Denmark and Norway, and received its current name in 1939. The university was commonly nicknamed "The Royal Frederick's" (''Det Kgl. Frederiks'') before the name change, and informally also referred to simply as ''Universitetet'' (). The university was the only university in Norway until the University of Bergen was founded in 1946. It has approximately 27,700 students and employs around 6,000 people. Its faculties include (Lutheranism, Lutheran) theology (with the Lutheran Church of Norway having been Norway's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbon-fiber-reinforced Polymers
Carbon fiber-reinforced polymers (American English), carbon-fibre-reinforced polymers (Commonwealth English), carbon-fiber-reinforced plastics, carbon-fiber reinforced-thermoplastic (CFRP, CRP, CFRTP), also known as carbon fiber, carbon composite, or just carbon, are extremely strong and light fiber-reinforced plastics that contain carbon fibers. CFRPs can be expensive to produce, but are commonly used wherever high strength-to-weight ratio and stiffness (rigidity) are required, such as aerospace, superstructures of ships, automotive, civil engineering, sports equipment, and an increasing number of consumer and technical applications. The binding polymer is often a thermoset resin such as epoxy, but other thermoset or thermoplastic polymers, such as polyester, vinyl ester, or nylon, are sometimes used. The properties of the final CFRP product can be affected by the type of additives introduced to the binding matrix (resin). The most common additive is silica, but other addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reaction Wheel
A reaction wheel (RW) is an electric motor attached to a flywheel, which, when its rotation speed is changed, causes a counter-rotation proportionately through conservation of angular momentum. A reaction wheel can rotate only around its center of mass; it is not capable of moving from one place to another ( translational force). Reaction wheels are used primarily by spacecraft for three-axis attitude control, and do not require rockets or external applicators of torque, which reduces the mass fraction needed for fuel. They provide a high pointing accuracy, and are particularly useful when the spacecraft must be rotated by very small amounts, such as keeping a telescope pointed at a star. A reaction wheel is sometimes operated at a constant (or near-constant) rotation speed, to provide a satellite with a large amount of stored angular momentum. Doing so alters the spacecraft's rotational dynamics so that disturbance torques perpendicular to one axis of the satellite (the axis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Simplified Perturbations Models
Simplified perturbations models are a set of five mathematical models (SGP, SGP4, SDP4, SGP8 and SDP8) used to calculate orbital state vectors of satellites and space debris relative to the Earth-centered inertial coordinate system. This set of models is often referred to collectively as SGP4 due to the frequency of use of that model particularly with two-line element sets produced by NORAD and NASA. These models predict the effect of perturbations caused by the Earth’s shape, drag, radiation, and gravitation effects from other bodies such as the sun and moon. Simplified General Perturbations (SGP) models apply to near earth objects with an orbital period of less than 225 minutes. Simplified Deep Space Perturbations (SDP) models apply to objects with an orbital period greater than 225 minutes, which corresponds to an altitude of 5,877.5 km, assuming a circular orbit. The SGP4 and SDP4 models were published along with sample code in FORTRAN IV in 1988 with refinements ov ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
International Geomagnetic Reference Field
The International Geomagnetic Reference Field (IGRF) is a standard mathematical description of the large-scale structure of the Earth's main magnetic field and its secular variation. It was created by fitting parameters of a mathematical model of the magnetic field to measured magnetic field data from surveys, observatories and satellites across the globe. The IGRF has been produced and updated under the direction of the International Association of Geomagnetism and Aeronomy (IAGA) since 1965. The IGRF model covers a significant time span, and so is useful for interpreting historical data. (This is unlike the World Magnetic Model, which is intended for navigation in the next few years.) It is updated at 5-year intervals, reflecting the most accurate measurements available at that time. The current 13th edition of the IGRF model (IGRF-13) was released in December 2019 and is valid from 1900 until 2025. For the interval from 1945 to 2015, it is "definitive" (a "DGRF"), meanin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rotation Group SO(3)
In mechanics and geometry, the 3D rotation group, often denoted SO(3), is the group of all rotations about the origin of three-dimensional Euclidean space \R^3 under the operation of composition. By definition, a rotation about the origin is a transformation that preserves the origin, Euclidean distance (so it is an isometry), and orientation (i.e., ''handedness'' of space). Composing two rotations results in another rotation, every rotation has a unique inverse rotation, and the identity map satisfies the definition of a rotation. Owing to the above properties (along composite rotations' associative property), the set of all rotations is a group under composition. Every non-trivial rotation is determined by its axis of rotation (a line through the origin) and its angle of rotation. Rotations are not commutative (for example, rotating ''R'' 90° in the x-y plane followed by ''S'' 90° in the y-z plane is not the same as ''S'' followed by ''R''), making the 3D rotation grou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sun Sensor
A Sun sensor is a navigational instrument used by spacecraft to detect the position of the Sun. Sun sensors are used for Spacecraft attitude control, attitude control, solar array pointing, gyroscope, gyro updating, and safe mode (spacecraft), fail-safe recovery. In addition to spacecraft, Sun sensors find use in ground-based weather stations and Sun-tracking systems, and aerial vehicles including Balloon (aeronautics), balloons and Unmanned aerial vehicle, UAVs. Mechanism There are various types of Sun sensors, which differ in their technology and performance characteristics. Sun presence sensors provide a binary number, binary output, indicating when the Sun is within the sensor's field of view. Analog electronics, Analog and digital electronics, digital Sun sensors, in contrast, indicate the angle of the Sun by continuous and discrete signal outputs, respectively. In typical Sun sensors, a thin slit at the top of a rectangular chamber allows a line of light to fall on an array ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnetometer
A magnetometer is a device that measures magnetic field or magnetic dipole moment. Different types of magnetometers measure the direction, strength, or relative change of a magnetic field at a particular location. A compass is one such device, one that measures the direction of an ambient magnetic field, in this case, the Earth's magnetic field. Other magnetometers measure the magnetic dipole moment of a magnetic material such as a ferromagnet, for example by recording the effect of this magnetic dipole on the induced current in a coil. The invention of the magnetometer is usually credited to Carl Friedrich Gauss in 1832. Earlier, more primitive instruments were developed by Christopher Hansteen in 1819, and by William Scoresby by 1823. Magnetometers are widely used for measuring the Earth's magnetic field, in geophysical surveys, to detect magnetic anomalies of various types, and to determine the dipole moment of magnetic materials. In an aircraft's attitude and heading ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
FreeRTOS
FreeRTOS is a real-time operating system Kernel (operating system), kernel for embedded devices that has been ported to 40 microcontroller platforms. It is distributed under the MIT License. History The FreeRTOS kernel was originally developed by Richard Barry around 2003, and was later developed and maintained by Barry's company, Real Time Engineers Ltd. In 2017, the firm passed stewardship of the FreeRTOS project to Amazon Web Services (AWS). Barry continues to work on FreeRTOS as part of an AWS team. With the transition to Amazon control, subsequent releases of the project also switched licensing from GPL version 2 (with special exceptions for static linking to proprietary code outside the FreeRTOS kernel itself) to MIT. Implementation FreeRTOS is designed to be small and simple. It is mostly written in the C (programming language), C programming language to make it easy to port and maintain. It also comprises a few assembly language functions where needed, mostly in archite ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
