Sun synchronous orbit definition of sun synchronous orbit. The earth sun orbit geometry for sun synchronous orbits with angular momentum vectors that project onto the earth sun line is such that orbits with inclinations greater than 115. Sunsynchronous orbit definition of sunsynchronous orbit. Synchronous orbit due to requirement of same light condition throughout the operational lifetime. In other words, the orbital plane has a fixed orientation with respect to the earthsun direction. An orbit in which the satellites orbital plane is at a fixed orientation to the sun, i. A sun synchronous orbit is an orbit around the earth, where the movement of the satellite always looks the same when viewed from the sun. Geometry of a sunsynchronous orbit landsat science.
Today we are having a look at the same orbits but showing how the orbit is actually a circle with the earth rotating inside it. Sun synchronous orbits for the earth solar power satellite. Like a polar orbit, the satellite travels from the north to the south poles. A sun synchronous orbit sometimes called a heliosynchronous orbit not verified in body is a geocentric orbit which combines altitude and inclination in such a way that an object on that orbit ascends or descends over any given point of the earths surface at the same local mean solar time. The obvious choice of launch vehicle for the mission is the soyuz2 due to its high payload to sun synchronous orbits.
In order for an orbit to be sun synchronous, the node line must move eastward at a rate of one revolution per year. Sun synchronous orbit how is sun synchronous orbit abbreviated. A sunsynchronous orbit is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planets surface at the same local mean. Characterization of the effects of a sunsynchronous orbit. The main achievements of the indian space programme included the launch on 17 october 2003 of a remote sensing satellite resourcesati which had been launched into a highly accurate polar sunsynchronous orbit by the indian launch vehicle pslv.
Of the five lagrange points in the sunearth system, only the last two. Hence, an object in geo synchronous will always appear stationary at all times from earth. The value of the inclination angle i will determine key attributes of an orbit. Analysis of the effects of mean local nodecrossing time on. So a circle is the special case in which the two foci merge to. Heres an example of a sunsynchronous orbit using the designer. Sunsynchronous orbit slot architecture analysis and development eric watson space debris growth and an in ux in space tra c will create a need for increased space tra c management. Apr 11, 20 this code is a matlab script that can be used to design and analyze sunsynchronous orbits.
The sunsynchronous orbit is one of the most frequently used orbits for earth science missions. Basic solutions for a single satellite have been obtained in the form of intervals of possible orbital parameters and coverage characteristics depending on a given interruption of observations of any given point on the. The apsidal precession for low earth sun synchronized orbits. As another answer correctly stated, a sunsynchronous orbit sso with a local time of ascending node ltan of 12 noon would experience the maximum eclipse since the vector to the sun would lie within the orbital plane and an orbit with an ltan of 11 am would experience an eclipse time of close to that. Satellites that take pictures of the earth would work best with bright sunlight. Satellites in geostationary orbit geo circle earth above the equator from west. Sunsynchronous orbit sso is a particular kind of polar orbit. In our solar system, the moon orbits earth, and earth orbits the sun, but that does. You are correct that a sun synchronous orbit is not possible in ksp since it depends on the j2 term iirc the measure of how much more mass is in the northern hemisphere than the southern, which ksp doesnt simulate or it approximates as 1 since kerbin is perfectly spherical with no gravitational inconsistency.
The soyuz2 launches from the baikonur cosmodrome and is capable of launching up to 4,500 kg to an 800km sun synchronous orbit. Development of an architecture of sunsynchronous orbital slots to minimize conjunctions brian weeden secure world foundation sunsynchronous orbit sso satellites serve many important functions, primarily in the areas of earth reconnaissance and weather. Like all of the landsat satellites, landsat 6 would have been in a sunsynchronous orbit had its launch been successful. California the sunsynchronous orbit is one of the most frequently used orbits for earth science missions. Figure 2 plots the results of equation 1, showing mean altitude versus mean inclination for sun synchronous orbits from 200 km to 5974 km in altitude. Sunsynchronous polar orbit, noon orbit, compare to. Polar sun synchronous orbit article about polar sun. Satellites can orbit earths equator or go over earths north and south poles, or anything in between.
Sun synchronous orbit how is sun synchronous orbit. Basic solutions for a single satellite have been obtained in the form of intervals of possible orbital parameters and coverage characteristics depending on a given interruption of observations of any given point on. Definition of sunsynchronous orbit in the dictionary. The launch of the satellite into a sunsynchronous duskdawn orbit with an 11 day repeat period is planned on top of a.
Apart from small seasonal variations, anchoring of the satellites orbit to the angle of the sun minimises the potential impact of shadows and levels of illumination on the ground. Sunsynchronous orbits american academy of arts and. Apparently there is a special orbit called sunsynchronous orbit, which is designed such that the satellite always crosses a given latitude on the day side of the earth at the same time of. In a sunsynchronous orbit, though, the satellite passes over the same part of the earth at roughly the same local time each day. Oct 23, 20 sunsynchronous polar orbit, noon orbit, compare to afternoon orbit. Find out information about polar sun synchronous orbit. A study was conducted to demonstrate the development of an extension of the sunsynchronous orbit, which as per definition is a finite resource similar to a geostationary orbit, the extension to. How sunsynchronous orbits differ from geosynchronous. A sunsynchronous orbit sso, also called a heliosynchronous orbit is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planets surface at the same local mean solar time. In a sun synchronous orbit, though, the satellite passes over the same part of the earth at roughly the same local time each day. Als sonnensynchrone umlaufbahn oder sonnensynchronen orbit auch sonnensynchronorbit. Generation of an optimum target trajectory for the terrasar. Polar orbits are a type of low earth orbit, as they are at low altitudes between 200 to km. Catalog of earth satellite orbits nasa earth observatory.
Due to orbital population density and likely future growth, the implementation of a slot architecture to sunsynchronous orbit. With this type of payload capability, it is possible to deploy all 90 satellites in a single. Chapter 5 principles of satellite remote sensing iup bremen. Sun synchronous orbit synonyms, sun synchronous orbit pronunciation, sun synchronous orbit translation, english dictionary definition of sun synchronous orbit. Citeseerx abcs of sunsynchronous orbit mission design. The multi sunsynchronous orbits are introduced first. The surface illumination angle will be nearly the same every time. Sun synchronous orbits with angular momentum vectors which. A study was conducted to demonstrate the development of an extension of the sun synchronous orbit, which as per definition is a finite resource similar to a geostationary orbit, the extension to.
Sunsynchronous orbit no eclipse period for satellites. The zeya satellite was used for navigation and geodesy tests from a sun synchronous orbit. Nov 24, 2016 this article describes a method for determining the parameters of a circular sun synchronous orbit and coverage characteristics of a satellite for realtime global coverage. Sunsynchronous polar orbit, noon orbit, compare to afternoon orbit. Sun synchronous orbits are those whose orbital plane makes a constant angle with the radial from the sun. Generally within the field of astrodynamics and mission analysis, the sunsynchronous orbit is understood to be a near polar orbit where the nodal precession rate is matched to the earths mean orbital rate around the sun. A sunsynchronous orbit is one that lies in a plane that. Sun synchronous orbit is achieved by exploiting the perturbing 1. Satellites in geostationary orbit rotate with the earth directly above the. They can orbit at a low altitude, or thousands of miles out in space.
The seastar satellite carries the seawifs instrument which was designed to monitor the color of the worlds oceans. Sunsynchronous orbits are those whose orbital plane makes a constant angle with the radial from the sun. A sun synchronous orbit exploits the precession of nodes due to the latitudinal perturbation in the earths gravitational field. An earth orbit of a spacecraft so that the craft is always in the same direction relative to that of the sun.
Note that this does not mean that the satellite passes over the same spot at the same local solar. In the united states, military vocabulary is standardized by the department of defence. Figure 2 plots the results of equation 1, showing mean altitude versus mean inclination for sunsynchronous orbits from 200 km to 5974 km in altitude. The sun synchronous orbit is one of the most frequently used orbits for earth science missions. More technically, it is an orbit arranged so that it precesses through one complete revolution each year, so it always maintains the same relationship with the sun.
The orbit, at a height of about 860 km oneseventh of an earth radius, takes about 102 minutes and carries the satellite over a different swathe of territory at each pass, so every point on the surface is overflown every 12 hours, at the. Sunsynchronous orbit a satellite orbit that remains constant in relation to the sun, passing close to both poles and crossing the meridians at an angle. Abcs of sunsynchronous orbit mission design ronald j. Sun synchronous orbit san francisco state university. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Moreover, these two subsystems are strongly in interaction with each other so that considering only one of them without the other one is not analytically and practically possible. Since there are 365 days in a year and 360 degrees in a circle, it means that the satellite has to shift its orbit by approximately one degree per day. Many of the leo nearpolar satellite orbits 700 to km are also sunsynchronous such that they cover each area of the world at a. The apsidal precession for low earth sun synchronized orbits shkelzen cakaj. The soyuz2 launches from the baikonur cosmodrome and is capable of launching up to 4,500 kg to an 800km sunsynchronous orbit. The obvious choice of launch vehicle for the mission is the soyuz2 due to its high payload to sunsynchronous orbits. The choice of orbit all depends on the satellites job. These orbits are used for satellites that need a constant amount of sunlight.
This paper contains the preliminary ideas on how to design orbits and constellations associated with extended sun synchronicity concepts. Jun 14, 2016 apparently there is a special orbit called sunsynchronous orbit, which is designed such that the satellite always crosses a given latitude on the day side of the earth at the same time of. Geostationary and sun synchronous satellites presented by. Sun synchronous orbit a satellite orbit that remains constant in relation to the sun, passing close to both poles and crossing the meridians at an angle.
Such an orbit is termed sunsynchronous and more details on that are given. Generally within the field of astrodynamics and mission analysis, the sun synchronous orbit is understood to be a near polar orbit where the nodal precession rate is matched to the earths mean orbital rate around the sun. This schematic appears in the landsat 6 programming and control handbook that was prepared by martin marietta astro space in 1993. Analysis of the effects of mean local nodecrossing time. Abcs of sun synchronous orbit mission design ronald j. Information and translations of sunsynchronous orbit in the most comprehensive dictionary definitions resource on the web. Name, orbit type, orbit height km, repeat cycle days, launched in, out of service since, organisation. This code is a matlab script that can be used to design and analyze sunsynchronous orbits.
Once youve created your desired orbit, it is automatically imported into the spacecraft resource for later use. A sunsynchronous orbit sometimes called a heliosynchronous orbit not verified in body is a geocentric orbit which combines altitude and inclination in such a way that an object on that orbit ascends or descends over any given point of the earths surface at the same local mean solar time. Figure 5 is a plot of the orbital periods of circular sun synchronous orbits versus orbital inclination. Mar 27, 20 sun synchronous orbit is a special kind of orbit. Sunsynchronous orbits are very popular for remote sensing. Dec 09, 2016 sun synchronous orbits these orbits allows a satellite to pass over a section of the earth at the same time of day. All satellites itc satellites and sensors database. A sunsynchronous orbit is an earth orbit which combines altitude and inclination in such a way that an object on that orbit passes over any given latitude of the earths surface at the same local solar time.
California the sun synchronous orbit is one of the most frequently used orbits for earth science missions. A sun synchronous orbit sso, also called a heliosynchronous orbit is a nearly polar orbit around a planet, in which the satellite passes over any given point of the planets surface at the same local mean solar time. This paper mainly aims at seeking for an optimal near sunsynchronous orbit for a nadirpointing satellite using evolutionary algorithms. Wow, this is where we get into the complexities or orbit mechanics. Orbit design for thai space consortium satellite mdpi. This article is within the scope of wikiproject spaceflight, a collaborative effort to improve the coverage of spaceflight on wikipedia. A sunsynchronous orbit is a geocentric orbit which combines altitude and inclination in such a way that an object in this orbit has an a nodal regression rate which is equals to earths orbital rotation speed around the sun. Jun 17, 2008 a sunsynchronous orbit precesses so that it makes a full circuit around the earth in 1 year, so it has a constant orientation with respect to the sun.
Sunsynchronous orbits are used to ensure the angle of sunlight upon the earths surface is consistently maintained. These orbits allows a satellite to pass over a section of the earth at the same time of day. The l6 handbook tells us, for a nominal sunsynchronous orbit i. By choosing the orbit inclination right, the propagation rate of the nodes can be synchronised with the suns node propagation about 1 degreeday. Most poes orbits are circular to slightly elliptical at distances ranging from 700. Sun synchronous orbit definition of sun synchronous. Sunsynchronous orbit from eric weissteins world of. A satellite can be natural, like the moon or it can be humanmade like, like the space. Sunsynchronous orbit definition militarydictionary. A sunsynchronous orbit exploits the precession of nodes due to the latitudinal perturbation in the earths gravitational field.
An orbit which takes advantage of the earth s bulge to rotate the plane of the orbit. Sun synchronous orbits in the absence of orbital perturbations the plane of an from aste 280 at university of southern california. Altitude 705 km nominal ground track equator inclination 98. To open the orbit designer, click the button on the spacecraft properties window. You are correct that a sunsynchronous orbit is not possible in ksp since it depends on the j2 term iirc the measure of how much more mass is in the northern hemisphere than the southern, which ksp doesnt simulate or it approximates as 1 since kerbin is perfectly spherical with no. If you would like to participate, please visit the project page, where you can join the discussion and see a list of open tasks. Geosynchronous orbits are those orbits in which object revolves in the same time as taken by earth rotation on its axis. In order for an orbit to be sun synchronous, the node line must move eastward at. By choosing the orbit inclination right, the propagation rate of the nodes can be synchronised with the sun s node propagation about 1 degreeday.
A sunsynchronous orbit is one that lies in a plane that maintains a fixed angle with respect to the earthsun direction. Development of an architecture of sun synchronous orbital slots to minimize conjunctions brian weeden secure world foundation sun synchronous orbit sso satellites serve many important functions, primarily in the areas of earth reconnaissance and weather. Pdf on sunsynchronous orbits and associated constellations. So orbits are not fixed in space, they tend to change over time, and one of the things that makes an orbit change is the shape of the earth. This article describes a method for determining the parameters of a circular sunsynchronous orbit and coverage characteristics of a satellite for realtime global coverage. Heres an example of a sun synchronous orbit using the designer. The multi sun synchronous orbits are introduced first. Sun synchronous orbits for the earth solar power satellite system.
Hence, an object in geosynchronous will always appear stationary at all times from earth. Like a polar orbit, the satellite travels from the north to the south poles as the earth turns below it. The changes during the year occur because apparent sun motion in. The zeya satellite was used for navigation and geodesy tests from a sunsynchronous orbit. As a result of this property, sunsynchronous orbits ensure that the satellite passes over a given location on earth every. Sun synchronous orbits are used to ensure the angle of sunlight upon the earths surface is consistently maintained. These satellites orbit at an altitude between 700 to 800 km. Sun synchronous orbits for the earth solar power satellite system pdf, eng. Boain jet propulsion laboratory california institute of technology pasadena.