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SumbandilaSat
SumbandilaSat (sometimes just Sumbandila, formerly ZASAT-002, AMSAT designation SO-67), was a South African micro Earth observation satellite, launched on 17 September 2009 on a Soyuz-2 launch vehicle from the Baikonur Cosmodrome. The first part of the name, Sumbandila, is from the Venda language and means "lead the way". The University of Stellenbosch, SunSpace and the CSIR (Council for Scientific and Industrial Research) were key players in constructing SumbandilaSat. The CSIR's Satellite Application Centre (CSIR-SAC) was responsible for operations, telemetry, tracking, control as well as data capturing. SumbandilaSat was part of a closely integrated South African space programme and served as a research tool to investigate the viability of affordable space technology. Furthermore, the data was used to, amongst others, monitor and manage disasters such as flooding, oil spills and fires within Southern Africa. In June 2011 the satellite was damaged during a solar storm. The d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Soyuz-2 (rocket)
Soyuz-2 (GRAU index 14A14) is a modernized version of the Soviet Soyuz rocket. In its basic form, it is a three-stage launch vehicle for placing payloads into low Earth orbit. Compared to the previous versions of the Soyuz, the first-stage boosters and two core stages feature uprated engines with improved injection systems. Digital flight control and telemetry systems allow the rocket to be launched from a fixed launch platform, whereas the launch platforms for earlier Soyuz rockets had to be rotated as the rocket could not perform a roll to change its heading in flight. Soyuz-2 is often flown with an upper stage, which allows it to lift payloads into higher orbits, such as Molniya and geosynchronous orbits. The upper stage is equipped with independent flight control and telemetry systems from those used in the rest of the rocket. The NPO Lavochkin manufactured Fregat is the most commonly used upper stage. Soyuz-2 rockets were first launched from Site 31 at the Baikonur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
University Of Stellenbosch
Stellenbosch University ( af, Universiteit Stellenbosch) is a public research university situated in Stellenbosch, a town in the Western Cape province of South Africa. Stellenbosch is the oldest university in South Africa and the oldest extant university in Sub-Saharan Africa, together with the University of Cape Town - which received full university status on the same day in 1918. Stellenbosch University (abbreviated as SU) designed and manufactured Africa's first microsatellite, SUNSAT, launched in 1999. Stellenbosch University was the first African university to sign the Berlin Declaration on Open Access to Knowledge in the Sciences and Humanities. The students of Stellenbosch University are nicknamed "Maties". The term probably arises from the Afrikaans word "tamatie" (meaning tomato, and referring to the maroon sports uniforms and blazer colour). An alternative theory is that the term comes from the Afrikaans colloquialism ''maat'' (meaning "buddy" or "mate"), originally u ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Software Defined Radio
Software-defined radio (SDR) is a radio communication system where components that have been traditionally implemented in analog hardware (e.g. mixers, filters, amplifiers, modulators/demodulators, detectors, etc.) are instead implemented by means of software on a personal computer or embedded system. While the concept of SDR is not new, the rapidly evolving capabilities of digital electronics render practical many processes which were once only theoretically possible. A basic SDR system may consist of a personal computer equipped with a sound card, or other analog-to-digital converter, preceded by some form of RF front end. Significant amounts of signal processing are handed over to the general-purpose processor, rather than being done in special-purpose hardware (electronic circuits). Such a design produces a radio which can receive and transmit widely different radio protocols (sometimes referred to as waveforms) based solely on the software used. Software radios have signif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacecraft Launched By Soyuz-2 Rockets
A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle (carrier rocket). On a sub-orbital spaceflight, a space vehicle enters space and then returns to the surface without having gained sufficient energy or velocity to make a full Earth orbit. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies. Spacecraft used for human spaceflight carry people on board as crew or passengers from start or on orbit (space stations) only, whereas those used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft used to support scientific re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Radio Satellites
An amateur () is generally considered a person who pursues an avocation independent from their source of income. Amateurs and their pursuits are also described as popular, informal, self-taught, user-generated, DIY, and hobbyist. History Historically, the amateur was considered to be the ideal balance between pure intent, open mind, and the interest or passion for a subject. That ideology spanned many different fields of interest. It may have its roots in the ancient Greek philosophy of amateur athletes competing in the Olympics. The ancient Greek citizens spent most of their time in other pursuits, but competed according to their natural talents and abilities. The "gentleman amateur" was a phenomenon among the gentry of Great Britain from the 17th century until the 20th century. With the start of the Age of Reason, with people thinking more about how the world works around them, (see science in the Age of Enlightenment), things like the cabinets of curiosities, and the w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SUNSAT
The Stellenbosch UNiversity SATellite or SUNSAT (COSPAR 1999-008C) was the first miniaturized satellite designed and manufactured in South Africa. It was launched aboard a Delta II rocket from the Vandenberg Air Force Base on 23 February 1999 to become the first launched South African satellite. Sunsat was built by post-graduate engineering students at the University of Stellenbosch. Its AMSAT designation was SO-35 (Sunsat Oscar 35). Last contact by ground control with SUNSAT was on 19 January 2001 and on 1 February 2001 the end of SUNSAT's functional life in orbit was announced. The satellite operated in orbit for nearly 2 years. It is predicted to reenter the atmosphere after about 30 years from launch. SUNSAT(SO-35) FAQ Specifications * Size ...[...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parrot Repeater
Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genera comprising the order Psittaciformes (), found mostly in tropical and subtropical regions. The order is subdivided into three superfamilies: the Psittacoidea ("true" parrots), the Cacatuoidea (cockatoos), and the Strigopoidea (New Zealand parrots). One-third of all parrot species are threatened by extinction, with higher aggregate extinction risk ( IUCN Red List Index) than any other comparable bird group. Parrots have a generally pantropical distribution with several species inhabiting temperate regions in the Southern Hemisphere, as well. The greatest diversity of parrots is in South America and Australasia. Characteristic features of parrots include a strong, curved bill, an upright stance, strong legs, and clawed zygodactyl feet. Many parrots are vividly coloured, and some are multi-coloured. Most parrots exhibit little or no sexual dimorphism in the visual spectrum. They form the most ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transponder
In telecommunications, a transponder is a device that, upon receiving a signal, emits a different signal in response. The term is a blend of ''transmitter'' and ''responder''. In air navigation or radio frequency identification, a flight transponder is an automated transceiver in an aircraft that emits a coded identifying signal in response to an interrogating received signal. In a communications satellite, a satellite transponder receives signals over a range of uplink frequencies, usually from a satellite ground station; the transponder amplifies them, and re-transmits them on a different set of downlink frequencies to receivers on Earth, often without changing the content of the received signal or signals. Satellite/broadcast communications A communications satellite’s channels are called transponders because each is a separate transceiver or repeater. With digital video data compression and multiplexing, several video and audio channels may travel through a single trans ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amateur Radio
Amateur radio, also known as ham radio, is the use of the radio frequency spectrum for purposes of non-commercial exchange of messages, wireless experimentation, self-training, private recreation, radiosport, contesting, and emergency communications. The term "amateur" is used to specify "a duly authorised person interested in radioelectric practice with a purely personal aim and without pecuniary interest;" (either direct monetary or other similar reward) and to differentiate it from commercial broadcasting, public safety (such as police and fire), or professional two-way radio services (such as maritime, aviation, taxis, etc.). The amateur radio service (''amateur service'' and ''amateur-satellite service'') is established by the International Telecommunication Union (ITU) through the Radio Regulations. National governments regulate technical and operational characteristics of transmissions and issue individual station licenses with a unique identifying call sign, which m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Very Low Frequency
Very low frequency or VLF is the ITU designation for radio frequencies (RF) in the range of 3–30 kHz, corresponding to wavelengths from 100 to 10 km, respectively. The band is also known as the myriameter band or myriameter wave as the wavelengths range from one to ten myriameters (an obsolete metric unit equal to 10 kilometers). Due to its limited bandwidth, audio (voice) transmission is highly impractical in this band, and therefore only low data rate coded signals are used. The VLF band is used for a few radio navigation services, government time radio stations (broadcasting time signals to set radio clocks) and for secure military communication. Since VLF waves can penetrate at least 40 meters (131 ft) into saltwater, they are used for military communication with submarines. Propagation characteristics Because of their long wavelengths, VLF radio waves can diffract around large obstacles and so are not blocked by mountain ranges, and can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
