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Beacon Mode Service
The beacon mode service is a Consultative Committee for Space Data Systems (CCSDS) telecommunications service aimed at spacecraft which are not communicated with (on a daily basis) via NASA's Deep Space Network. It is primarily designed to relay a spacecraft's "health" information, and secondarily its telecommunications status, using a simple signal that can be detected with a moderately-sized antenna. Beacon mode also enables spacecraft to communicate with one another on a daily basis, allowing for one spacecraft to act as a data proxy for another. The CCSDS tone beacon mode configures the transceiver to transmit a CW tone. It can be used to signal other spacecraft to transmit their data to an orbiter; however, its primary function is to transmit spacecraft health information. Addressing multiple spacecraft is accomplished by using four unique CW frequencies with 16 possible tones, used somewhat like DTMF signaling technology. In the outer solar system, UHF frequencies are not use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Consultative Committee For Space Data Systems
The Consultative Committee for Space Data Systems (CCSDS) was founded in 1982 for governmental and quasi-governmental space agencies to discuss and develop standards for space data and information systems. Currently composed of "eleven member agencies, twenty-eight observer agencies, and over 140 industrial associates," the CCSDS works to support collaboration and interoperability between member agencies through the establishment of data and system standards. According to the organisation's website, more than 1000 space missions have utilized data and systems standards created by CCSDS. The activities of the CCSDS are organized around six topic areas and composed of many working groups within the overall Collaborative Working Group Environment (CWE). Publications and standards The CCSDS is divided into 6 Technical areas: * Space Internetworking Services * Mission Operations And Information Management Services * Spacecraft Onboard Interface Services * System Engineering * Cross Sup ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Safe Mode (spacecraft)
Safe mode is an operating mode of a modern unmanned spacecraft during which all non-essential systems are shut down and only essential functions such as thermal management, radio reception and attitude control are active. Safe mode is entered automatically upon the detection of a predefined operating condition or event that may indicate loss of control or damage to the spacecraft. Usually the trigger event is a system failure or detection of operating conditions considered dangerously out of the normal range. Cosmic rays penetrating spacecraft electrical systems can create false signals or commands and thus cause a trigger event. The central processor electronics are especially prone to such events. Another trigger is the lack of a received command within a given time window. Lack of received commands can be caused by hardware failures or mis-programming of the spacecraft, as in the case of the Viking 1 lander. The process of entering safe mode, sometimes referred to as ''safing'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite Communications
A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via a transponder; it creates a communication channel between a source transmitter and a receiver at different locations on Earth. Communications satellites are used for television, telephone, radio, internet, and military applications. Many communications satellites are in geostationary orbit above the equator, so that the satellite appears stationary at the same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit, where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. The high frequency radio waves used for telecommunications links travel by line of sight and so are obstructed by the curve of the Earth. The purpose of communications satelli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radio Astronomy
Radio astronomy is a subfield of astronomy that studies celestial objects at radio frequencies. The first detection of radio waves from an astronomical object was in 1933, when Karl Jansky at Bell Telephone Laboratories reported radiation coming from the Milky Way. Subsequent observations have identified a number of different sources of radio emission. These include stars and galaxies, as well as entirely new classes of objects, such as radio galaxies, quasars, pulsars, and masers. The discovery of the cosmic microwave background radiation, regarded as evidence for the Big Bang theory, was made through radio astronomy. Radio astronomy is conducted using large radio antennas referred to as radio telescopes, that are either used singularly, or with multiple linked telescopes utilizing the techniques of radio interferometry and aperture synthesis. The use of interferometry allows radio astronomy to achieve high angular resolution, as the resolving power of an interferometer is set ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Doppler Effect
The Doppler effect or Doppler shift (or simply Doppler, when in context) is the change in frequency of a wave in relation to an observer who is moving relative to the wave source. It is named after the Austrian physicist Christian Doppler, who described the phenomenon in 1842. A common example of Doppler shift is the change of pitch heard when a vehicle sounding a horn approaches and recedes from an observer. Compared to the emitted frequency, the received frequency is higher during the approach, identical at the instant of passing by, and lower during the recession. The reason for the Doppler effect is that when the source of the waves is moving towards the observer, each successive wave crest is emitted from a position closer to the observer than the crest of the previous wave. Therefore, each wave takes slightly less time to reach the observer than the previous wave. Hence, the time between the arrivals of successive wave crests at the observer is reduced, causing an increa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phoenix (spacecraft)
''Phoenix'' was an uncrewed space probe that landed on the surface of Mars on May 25, 2008, and operated until November 2, 2008. ''Phoenix'' was operational on Mars for sols ( days). Its instruments were used to assess the local habitability and to research the history of water on Mars. The mission was part of the Mars Scout Program; its total cost was $420 million, including the cost of launch. The multi-agency program was led by the Lunar and Planetary Laboratory at the University of Arizona, with project management by NASA's Jet Propulsion Laboratory. Academic and industrial partners included universities in the United States, Canada, Switzerland, Denmark, Germany, the United Kingdom, NASA, the Canadian Space Agency, the Finnish Meteorological Institute, Lockheed Martin Space Systems, MacDonald Dettwiler & Associates (MDA) and other aerospace companies. It was the first NASA mission to Mars led by a public university. ''Phoenix'' was NASA's sixth successful landing on Ma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proximity-1 Space Link Protocol
Proximity-1 Space Link Protocol is a short haul delivery communications protocol designed to establish a two-way communications link between a lander and an orbiter, negotiate data rate and communications mode, and reliably deliver data during short orbiter-to-surface contacts. Developed by Consultative Committee for Space Data Systems and documented in a number of CCSDS Recommendations Proximity-1 is implemented on Mars Exploration Rovers, Mars Odyssey, Mars Reconnaissance Orbiter, Mars Express as well as on Phoenix Mars Lander. The frequency band used by this protocol is in the 70-centimeter band The 70-centimeter or 440 MHz band is a portion of the UHF radio spectrum internationally allocated to amateur radio and amateur satellite use. The ITU amateur radio allocation is from 430 to 440 MHz; however, some countries, such as the U ... so as to reduce complexity of the ground craft, using these frequencies: * 437.1000 MHz * 440.7425 MHz * 444.3850 MHz * ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mars Rovers
A Mars rover is a motor vehicle designed to travel on the surface of Mars. Rovers have several advantages over stationary landers: they examine more territory, they can be directed to interesting features, they can place themselves in sunny positions to weather winter months, and they can advance the knowledge of how to perform very remote robotic vehicle control. They serve a different purpose than orbital spacecraft like ''Mars Reconnaissance Orbiter''. A more recent development is the Mars helicopter. , there have been six successful robotically operated Mars rovers; the first five, managed by the American NASA Jet Propulsion Laboratory, were (by date of Mars landing): ''Sojourner'' (1997), ''Spirit'' (2004–2010), ''Opportunity'' (2004–2018), ''Curiosity'' (2012–), and ''Perseverance'' (2021–). The sixth, managed by the China National Space Administration, is ''Zhurong'' (2021–). On January 24, 2016, NASA reported that then current studies on Mars by ''Opportunit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Space 1
''Deep Space 1'' (DS1) was a NASA technology demonstration spacecraft which flew by an asteroid and a comet. It was part of the New Millennium Program, dedicated to testing advanced technologies. Launched on 24 October 1998, the ''Deep Space 1'' spacecraft carried out a flyby of asteroid 9969 Braille, which was its primary science target. The mission was extended twice to include an encounter with comet 19P/Borrelly and further engineering testing. Problems during its initial stages and with its star tracker led to repeated changes in mission configuration. While the flyby of the asteroid was only a partial success, the encounter with the comet retrieved valuable information. The Deep Space series was continued by the ''Deep Space 2'' probes, which were launched in January 1999 piggybacked on the Mars Polar Lander and were intended to strike the surface of Mars (though contact was lost and the mission failed). ''Deep Space 1'' was the first NASA spacecraft to use ion thruster, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Future Proof
Future-proofing is the process of anticipating the future and developing methods of minimizing the effects of shocks and stresses of future events. Future-proofing is used in industries such as electronics, medical industry, industrial design, and more recently, in design for climate change. The principles of future-proofing are extracted from other industries and codified as a system for approaching an intervention in an historic building. Electronics and communications In future-proof electrical systems, buildings should have "flexible distribution systems to allow communication technologies to expand.,Coley, David, Tristan Kershaw, and Matt Eames. "A Comparison of Structural and Behavioural Adaptations to Future Proofing Buildings against Higher Temperatures." Building and Environment 55 (2012): 159–66. Image-related processing software should be flexible, adaptable, and programmable to be able to work with several different potential media in the future as well as to h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deep Space Network
The NASA Deep Space Network (DSN) is a worldwide Telecommunications network, network of American spacecraft communication ground segment facilities, located in the United States (California), Spain (Madrid), and Australia (Canberra), that supports National Aeronautics and Space Administration, NASA's interplanetary spaceflight, interplanetary spacecraft missions. It also performs radio astronomy, radio and radar astronomy observations for the exploration of the Solar System and the universe, and supports selected Earth-orbiting missions. DSN is part of the NASA Jet Propulsion Laboratory (JPL). General information DSN currently consists of three deep-space communications facilities placed approximately 120 degrees apart around the Earth. They are: * the Goldstone Deep Space Communications Complex () outside Barstow, California, Barstow, California. For details of Goldstone's contribution to the early days of space probe tracking, see Project Space Track (1957-1961), Project ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
New Horizons
''New Horizons'' is an Interplanetary spaceflight, interplanetary space probe that was launched as a part of NASA's New Frontiers program. Engineered by the Johns Hopkins University Applied Physics Laboratory (APL) and the Southwest Research Institute (SwRI), with a team led by Alan Stern, the spacecraft was launched in 2006 with the primary mission to perform a Planetary flyby, flyby study of the Pluto system in 2015, and a secondary mission to fly by and study one or more other Kuiper belt objects (KBOs) in the decade to follow, which became a mission to 486958 Arrokoth. It is the List of artificial objects leaving the Solar System, fifth space probe to achieve the escape velocity needed to leave the Solar System. On January 19, 2006, ''New Horizons'' was launched from Cape Canaveral Space Force Station by an Atlas V rocket directly into an Earth-and-solar Escape velocity, escape trajectory with a speed of about . It was the fastest (average speed with respect to Earth) man ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
