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Resident Space Object
A Resident Space Object (RSO) is a natural or artificial object that orbits another body e.g. Sun Orbiting, Earth Orbiting, Mars Orbiting etc. It is most often used to reference objects that are Earth orbiting. In the case of Earth orbiting the possible orbit classifications for an object are: Low Earth orbit (LEO), Medium Earth orbit (MEO), High Earth orbit (HEO) or Geosynchronous Earth orbit (GEO). Identification of RSOs RSO acquisition, tracking, and data collection can be extremely challenging. The primary method for gathering this information is to make a direct observation of an RSO via Space surveillance Space domain awareness is the study and monitoring of satellites orbiting the earth. It involves the detection, tracking, cataloging and identification of artificial objects, i.e. active/inactive satellites, spent rocket bodies, or fragmentatio ... sensors. However the system is not foolproof and RSOs can become lost to the tracking system. Additionally not all new obj ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Earth Orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never more than about one-third of the radius of Earth. The term ''LEO region'' is also used for the area of space below an altitude of (about one-third of Earth's radius). Objects in orbits that pass through this zone, even if they have an apogee further out or are sub-orbital, are carefully tracked since they present a collision risk to the many LEO satellites. All crewed space stations to date have been within LEO. From 1968 to 1972, the Apollo program's lunar missions sent humans beyond LEO. Since the end of the Apollo program, no human spaceflights have been beyond LEO. Defining characteristics A wide variety of sources define LEO in terms of altitude. The altitude of an object in an elliptic orbit can vary significantly along the orbit. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium Earth Orbit
A medium Earth orbit (MEO) is an geocentric orbit, Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.''Catalog of Earth Satellite Orbits'' NASA Earth Observatory. 4 September 2009. Accessed 2 May 2021. The boundary between MEO and LEO is an arbitrary altitude chosen by accepted convention, whereas the boundary between MEO and HEO is the particular altitude of a geosynchronous orbit, in which a satellite takes 24 hours to circle the Earth, the same period as the Earth’s own rotation. All satellites in MEO have an orbital period of less than 24 hours, with the minimum period (for a circular orbit at the lowest MEO altitude) about 2 hours. Satellites in MEO or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High Earth Orbit
A high Earth orbit is a geocentric orbit with an altitude entirely above that of a geosynchronous orbit (). The orbital periods of such orbits are greater than 24 hours, therefore satellites in such orbits have an apparent retrograde motion – that is, even if they are in a prograde orbit (0° ≤ inclination < 90°), their orbital velocity is lower than al speed, causing their to move westward on 's surface. Examples of satellites in high Earth orbit See al ...
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Geosynchronous Orbit
A geosynchronous orbit (sometimes abbreviated GSO) is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds (one sidereal day). The synchronization of rotation and orbital period means that, for an observer on Earth's surface, an object in geosynchronous orbit returns to exactly the same position in the sky after a period of one sidereal day. Over the course of a day, the object's position in the sky may remain still or trace out a path, typically in a figure-8 form, whose precise characteristics depend on the orbit's inclination and eccentricity. A circular geosynchronous orbit has a constant altitude of . A special case of geosynchronous orbit is the geostationary orbit (often abbreviated ''GEO''), which is a circular geosynchronous orbit in Earth's equatorial plane with both inclination and eccentricity equal to 0. A satellite in a geostationary orbit remains in the same position in the sky to observe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Surveillance
Space domain awareness is the study and monitoring of satellites orbiting the earth. It involves the detection, tracking, cataloging and identification of artificial objects, i.e. active/inactive satellites, spent rocket bodies, or fragmentation debris. Aims Space domain awareness accomplishes the following: * Predicting when and where a decaying space object will re-enter the Earth's atmosphere; * Preventing a returning space object, which to radar looks like a missile, from triggering a false alarm in missile-attack warning sensors; * Charting the present position of space objects and plot their anticipated orbital paths; * Detecting new man-made objects in space; * Producing a running catalogue of man-made space objects; * Determining which country owns a re-entering space object; * Informing countries whether or not objects may interfere with satellites and International Space Station orbits; * Providing data for future anti-satellite weapons systems. Systems Systems in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two-line Element Set
A two-line element set (TLE) is a data format encoding a list of orbital elements of an Earth-orbiting object for a given point in time, the ''epoch''. Using a suitable prediction formula, the state (position and velocity) at any point in the past or future can be estimated to some accuracy. The TLE data representation is specific to the simplified perturbations models (SGP, SGP4, SDP4, SGP8 and SDP8), so any algorithm using a TLE as a data source must implement one of the SGP models to correctly compute the state at a time of interest. TLEs can describe the trajectories only of Earth-orbiting objects. TLEs are widely used as input for projecting the future orbital tracks of space debris for purposes of characterizing "future debris events to support risk analysis, close approach analysis, collision avoidance maneuvering" and forensic analysis. The format was originally intended for punched cards, encoding a set of elements on two standard 80-column cards. This format was ev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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