Earth orbitorGeocentric orbit(Geocentric orbit) isMonth,Artificial satellitelike地球It is an orbit that orbits around.So far, more than 16,291 objects have been launched from the earth in orbit around the earth, and currently about 2,465 artificial satellites are orbiting the earth, and 6,216.Space debris Goddard Space Flight CenterIs being monitored by.On the other hand, other than the above, it burned out in the atmosphere of the earth.

the term

• Analemma ――One year(I.e. OfCelestial sphereA term used to describe the movement above, similar to the figure eight.
• height ――Here, it represents the height from the earth.
• Far point --At the point where artificial satellites and celestial bodies are farthest from the earth, the orbital speed is the minimum.
• Orbital eccentricity ――A quantity that indicates how much the orbit deviates from the perfect circle.circular orbit,Elliptical orbit,Parabolic trajectory,Hyperbolic trajectoryCan be defined exactly.
• --Here, of the earthequatorialRepresents a virtual plane that extends on the celestial sphere.
• Orbital element --Six parameters needed to identify the uniqueness of the orbit.
• Escape velocity --Here, it represents the minimum velocity required for an object without propulsion to move infinitely away from the earth.Objects of this velocity draw a parabolic trajectory, and objects above this velocity draw a hyperbolic trajectory.
• Impulse --Power in timeintegralThe value is expressed in units of Newton seconds.
• Orbital inclination --The angle between the reference plane and other planes and axes, where the reference plane is the equatorial plane of the Earth.
• Orbital period ――Here, it is the time to go around the earth.
• Perigee --The orbital speed is maximum at the point where artificial satellites and celestial bodies are closest to the earth.
• Sidereal day --This is the time required for the celestial body to rotate 360 ​​°.It is equivalent to 23 hours 56 minutes 4.091 seconds on the earth.
• Sun time - here,SundialIt is the time for each region measured in.
• speed --The speed of an object in a particular direction.Since velocity is defined by a vector, we need two quantities, velocity and direction.

Types of geocentric orbit

Below is a list of geocentric orbit types.

Classification by altitude

• Low orbit(LEO) --Earth-centered orbits from 160km to 2,000km above average ocean surface.In an orbit at an altitude of 160 km, the orbital period is about 90 minutes, and the speed in a circular orbit is about 8,000 m / s.
• Medium earth orbit(MEO) --Earth-centered orbits with distant altitudes from 2,000 km to 35,786 km.
• Geosynchronous orbit(GEO) --Orbit at an altitude of 35,786 km centered on the earth.The orbital period is equal to the sidereal day of the earth.The speed is about 3,000 m / s.
• High orbit(HEO) --Orbit around the earth with an altitude of 35,786 km or more at a distant point.Especially when the altitude of the perigee is 2,000 km or lessHighly elliptical orbitと 呼 ば れ る^[1].

Classification by orbit inclination angle

• Inclined orbit --Orbits whose orbit inclination angle with respect to the equatorial plane is not 0 °.
  • Polar orbit --Orbits that pass over or near the poles of the earth in each orbit.The orbit inclination angle is 90 °.
  • Sun-synchronous orbit --A orbit close to the polar orbit that passes through the equator at the same time.It is suitable for taking images because the shadow of the sun is the same everywhere.

Classification by orbital eccentricity

• circular orbit --Orbit A circular orbit with an eccentricity of 0.
• Elliptical orbit --Orbit An elliptical orbit with an eccentricity between 0 and 1.
  • Hohmann transition orbit --A transition orbit when a spacecraft moves from one circular orbit to another using an engine.Walter HohmannNamed after.
  • Geostationary transfer orbit --An elliptical orbit centered on the earth with a low earth orbit at the near point and a geosynchronous orbit at the apogee.
  • Highly elliptical orbit(HEO)-Orbit with 35,786km or more and perigee of about 1,000km or less.The residence time at a distant point is long.
    • Molniya orbit --Highly elliptical orbit with an orbital inclination of 63.4 ° and an orbital period of 0.5 sidereal day (about 12 hours).Satellites stay above a particular location on Earth most of the time.
    • Tundra orbit --Highly elliptical orbit with an orbital inclination of 63.4 ° and an orbital period of 1 sidereal day (about 24 hours).Satellites stay above a particular location on Earth most of the time.
• Hyperbolic trajectory --In an "orbit" where the orbital eccentricity exceeds 1, the speed of the object at the near point exceeds the escape velocity, shakes off the gravity of the earth, and decelerates to a constant speed called "hyperbolic point at infinity speed" Continue to fly indefinitely.
• Parabolic trajectory --In an "orbit" where the orbital eccentricity is equal to 1, the velocity of the object at the near point becomes equal to the escape velocity and shakes off the gravity of the earth, but the velocity becomes 0.A spacecraft launched from Earth at this speed travels a certain distance, but near the Sun.Orbit around the sunto go into.If the velocity and angle are accurate, it is not impossible for an object heading for the earth to take this orbit.

Classification by direction

• Retrograde --The projection on the equatorial planeRotation of the earthOrbit in the same direction as.
• Retrograde --Orbit in which the projection on the equatorial plane is in the opposite direction to the rotation of the earth.

Classification by geosynchronous

• Semi-synchronous orbit(SSO) --Orbit with an altitude of about 20,200 km and an orbital period of about 12 hours.
• Geosynchronous orbit(GEO) --Orbit at an altitude of about 35,786 km.Objects in this orbit draw an analemma.
  • Geostationary orbit(GSO) --Geosynchronous orbit with an orbit inclination of 0 °.To ground observers, the spacecraft appears to be at a fixed point in the sky.Arthur C. ClarkDerived fromClark orbitThere is another name.
    • Lagrange point: The Lagrange points of objects orbiting the earth are at 105 ° west and 75 ° east. More than 160 artificial satellites are gathered at these two points^[2].
  • Graveyard orbit ――The orbit that is several hundred kilometers above the geosynchronous orbit and where artificial satellites that have finished operation are gathered.

Special classification

• Sun-synchronous orbit - the sameStandard timeAn orbit with an altitude and an orbital inclination so that you can see an artificial satellite passing by at any point on the earth.The satellite can be placed in the sunlight of the same conditions,Reconnaissance satellite,Meteorological satelliteSuitable for
• Lunar orbit --Moon orbit.It is an elliptical orbit with an average altitude of 384,403 km.

footnote

Annotation/Source

• "Satellite Situation ReportNASA Goddard Space Flight Center (February 2000, 2). As of August 1, 2006original^{[Broken link]}More archives.2006/9/10Browse.
• http://www.freemars.org/jeff/speed/index.htm
• http://www.tech-faq.com/medium-earth-orbit.shtml
• http://www.hq.nasa.gov/office/pao/History/conghand/traject.htm
• http://www.space.com/scienceastronomy/solarsystem/second_moon_991029.html
• http://www.astro.uwo.ca/~wiegert/3753/3753.html
• http://www.astro.uwo.ca/~wiegert/AA29/AA29.html

Related item

• Orbit around the sun
• Mars orbit

Artificial satellite(Jinkou Eisei,British: artificial satellite) Is惑星,mainly地球 OfOrbitBeing on top and having a specific purposeArtificial celestial body..On the earth, an objectrocketPut onFirst cosmic velocity(TheoreticallyAbove sea levelAt 0 m, about 7.9 km / s = 28,400 km / h^{[Note 1]}) By acceleratingEarth's gravityAnd trying to escape from gravityCentrifugal forceIs balanced, and the object isEarth orbitBecome an artificial satellite that keeps orbiting^[1]..However, even if it continues to orbit, debris of used rockets and fragments of artificial satellites that have no purpose areSpace debrisDistinguished as.Also, orbits other than planets (Lunar orbit,Orbit around the sun) Orbiting artificial celestial bodiesSpace probeIs generally distinguished.Also referred to simply as a "satellite" in the context of what is clearly known to be an artifact.

Manned spacecraft,Space station,space shuttleIs also included in the artificial satellite,US Aerospace AgencyAlthough it is also published in artificial satellite orbit data such as, it is generally not called an artificial satellite when referring to these.

Mankind's first artificial satellite1957/ToSoviet UnionLaunchedSputnik 1.21st centuryBy the beginning, thousands of satellites had been launched into orbit around the earth.

Artificial satellites have a wide variety of uses, and the most common ones areMilitary satellite,Reconnaissance satellite,Communication satellite,Broadcast satellite,Earth observation satellite,Navigation satellite,Meteorological satellite,Science satellite,Amateur satelliteAnd so on.

Most artificial satellites are in orbit around the earth,Planetary explorationFor the purpose火星,SaturnSome observation aircraft have reached the orbits of other planets such as, and they are artificial satellites of each planet.These make observations of planets,Mars probeVarious observation data from space probes that have landed on the surface of other planets are relayed to the earth.

History

Concept

The first time an artificial satellite was drawn in fiction(English edition）Short story, "(English edition）].This storyThe atlantic monthly Made into a series from 1869^[2][3]..This concept first appeared in 1879.Jules Verneof"(English edition）].

1903/,Konstantin TsiolkovskyIs "Space Exploration with Reaction Utilization Device" (Russian: Exploration of world spaces by jet instruments) Is published.This is for launching a spaceshipRocket engineeringIt was the first academic paper on.Tsiolkovsky is required for the smallest orbit of the earthOrbital speedIs calculated as 8km / s,Liquid fuelIt was usedMulti-stage rocketIf so, it is achievable.Also heLiquid hydrogenとLiquid oxygenSuggested the use of.

1928 years,スロベニア Of(English edition） The Problem of Space Travel — The Rocket Motor(German: Das Problem der Befahrung des Weltraums — der Raketen-Motor) Was published and described space travel and human permanent stay.He conceived a space station and calculated the geostationary orbit of the station.He also described in detail that artificial satellites can be used for peaceful and military observations on the ground, about the significance of special conditions in outer space for scientific experiments, and the use of geostationary satellites for communications, etc. Also mentioned.

1945 years,Arthur C. ClarkIs a magazine(English edition）Above, using a communication satelliteMass communicationDescribed in detail the possibility of^[4]..Clark also investigated plans for artificial satellite launches, possible satellite orbits, and proposed that three geostationary orbit satellites cover the entire globe.

Birth of artificial satellite

Second World WarDeveloped inGermany OfV2 rocketWith its technology and its engineers, rocket technology in the United States and the Soviet Union has made rapid progress, and artificial satellites are becoming a reality.

United States of America1945/Than(English edition）Under the circumstances, we have been considering the launch of an artificial satellite.1946/U.S. Air Force in MayLand InstituteReport, "Preliminary Design of Experimental Orbiting Spacecraft" (Preliminary Design of a Experimental World-Circling Spaceship ) States that "artificial satellites equipped with suitable equipment can be one of the most powerful scientific tools of the 20th century."^[5]I didn't think artificial satellites had military significance, but rather scientific, political, and propaganda at the time.US Secretary of Defense The1954/"I don't know about domestic artificial satellite plans" (I know of no American satellite program)^[6].

1955/May 7,White House The1958/Announced that it will launch an artificial satellite by the spring of.this isVanguard planBecame known as.On July 7, the same year, the Soviet Union1957/Announced that it will launch an artificial satellite by the fall of.

Sergey KorolevAnd assistant(English edition）Of the Soviet Union led bySputnik programBegins,1957/May 10The first artificial satellite "Sputnik 1Was launched^[7]..Sputnik 1 helped confirm the density of the upper atmosphere by analyzing its orbital changes, and provided data on radio signal disturbances in the ionosphere.The satellite's airframe was filled with pressurized nitrogen, and temperature data sent to Earth revealed that meteorites penetrated the airframe's surface and reduced internal pressure.This is the firstMeteoroidIt was the detection of.

This sudden successThe United States of AmericaToSputnik shockAnd then the fierceness of the United States and the Soviet UnionSpace development competitionWas connected to.

In June 1, three and a half years after Sputnik 3, the U.S. Air Force(English edition）Created a list of 115 artificial satellites using the resources of^[8].

Space surveillance network

The United States Space Surveillance Network (SNN) has been tracking space objects since 1957, and as of 2008 it has been tracking more than 8,000 artificial objects.The number of man-made objects in orbitT5 from artificial satelliteskilogramThere are various parts such as rocket parts.These 7 percent are artificial satellites in operation, and everything elseSpace debrisIs^[9].

SNN is tracking objects over 10 cm in diameter.US Strategic ArmyIs primarily interested in active satellites, but is also tracking space debris that will re-enter so as not to mistake it for a missile approach.

Non-military satellite service

There are basically three types of non-military artificial satellite operations.^[10].

Fixed satellite service

(English edition）Processes hundreds of billions of voice, video, and data communications tasks between specific points across countries and continents.

Mobile satellite system

Mobile satellite systems are used not only as navigation systems for cars, ships, planes and people in remote areas, but also for communicating with other mobile and fixed communication devices in different parts of the world.

Scientific observation satellite (commercial / non-profit)

Scientific observation satellites include meteorological information and ground information.Earth scienceof,oceanographyof,Atmospheric physicsUsed for surveys.

Classification of artificial satellites

Classification by purpose

• Military satellite --Satellite for military purposes.The most launched satellite ever.
  • Satellite attack weapon/ Killer satellite --A weapon for attacking enemy satellites.Particle beam weapons, energy weapons,Kinetic energy weapon,Nuclear missile, Or normalmissileDestroy using.
  • Reconnaissance satellite/ Spy satellite --For military purposesRemote sensing satellite,Communication satellite..These full capabilities are rarely known because the operating government keeps the information secret.Early warning satelliteIs classified here.
• Communication satellite - TelecommunicationsA satellite aimed at. Communication satellites in the early 21st century are generallyGeosynchronous orbit,Molniya orbit,Low orbitTo use.
  • Broadcast satellite --A satellite that relays radio waves transmitted from terrestrial broadcasting stations to the antennas of each household.
• Science satellite --A satellite for the purpose of scientific observation of celestial bodies such as the earth, planets, and the sun, and outer space such as cosmic rays and the ionosphere.
  • Space telescope/ Astronomical satellite --Other than the earth惑星,GalaxyA satellite whose purpose is to observe celestial bodies in outer space.
  • Planetary orbiter - 火星,JupiterA satellite that orbits.It is rarely called an artificial satellite.
• Earth observation satellite --Environmental monitoringMeteorology,CartographyAn artificial satellite for the purpose of non-military observations on the earth.Meteorological satelliteAnd are classified here.Earth observation systemSee.
• Biosatellite - AstrobiologyA satellite on which living things are placed for the purpose.Not classified as a scientific satellite.
• Navigation satellite --A satellite that sends radio alarm signals so that portable receivers on the ground can determine the exact location of the current location.With a few meters of error in real timeSatellite navigation systemWas made possible.GPS satellite.

Other classifications

• Small satellite--Small and lightweight artificial satellite^[11].Amateur satellite,Piggyback satellite,CubeSatMost of them are classified here.The new classification method is further divided into mini satellites (500-100 kg), micro satellites (100-10 kg), and nano satellites (10 kg or less).^[12].
• Space station --A structure designed so that humans can survive in outer space.Other in that there is no propulsion / landing gearManned spacecraftIs distinguished from.
• - Nuclear powerA satellite powered by.It was launched by the US and Soviet Union in the early stages of space development, but it has not been launched at present.SovietCosmos 954Fell to Canada.
• Tether satellite --A satellite connected to other satellites with a thin cable called a tether.

Concept

• Solar power satellite --In orbitSolar powerAnd powerMicrowaveA satellite sent to the ground by such means.Space solar powerSee.
• Cleaning satellite --A satellite intended to remove debris. JAXA embarked on development by 2020^[13]..Attach a conductive tether (string) to the debris to lower the trajectoryEnter the atmosphereThe idea is advocated (Tether promotionSee also)^[14][15]..Tether developmentFishing netManufacturer'sNitto NetAre working together^[16]..The name is tentative.

Orbit type

World's first artificial satelliteSputnik 1 TheEarth orbitWas launched into.Currently of this kindOrbitIs the most common, so the earth is often omitted in the orbital name.Orbits around the earth are further classified by altitude, orbital inclination, and orbital eccentricity.

Classification by center

• - GalaxyAn orbit that orbits the center of.The sun of the earthGalaxy OfGalactic coreSince it orbits, it is classified into this orbit.
• Orbit around the sun --Orbit around the sun.In the solar system, all planets, dwarf planets, comets, and asteroids belong to this orbit.When the artificial satellite enters this orbitArtificial planetAlso called.
• Earth orbit --A orbit that orbits the earth like the moon.2006/At that time, there are approximately 2465 satellites in this orbit.
• Lunar orbit --Orbit around the moon, the natural satellite of the earth.Lunar probeSee.Month(Average altitude 384,403 km,ellipse-Inclined orbit) And the earth.
• Mars orbit - Mars moonsAn orbit that orbits around Mars like this.

Classification by altitude

• Low orbit (LEO) --Earth orbit at an altitude of 2,000 km or less.The International Space Station and others are in this orbit.
• Medium earth orbit (MEO) --From an altitude of 2,000kmGeosynchronous orbitOrbit around the earth up to (35,786km).
• High orbit (HEO) --Earth orbit outside the geosynchronous orbit.

Classification by orbit inclination angle

• Inclined orbit --SatelliteOrbital inclinationOrbit that is tilted with respect to the equator of the planet.
  • Polar orbit --Planetaryvery, Or an orbit that passes over the very vicinity.Therefore, the orbit inclination angle is close to 90 °.
  • verySun-synchronous orbit --Close to polar orbit,equatorialOrbit that always passes through at the same local time.影Is convenient for taking images because it can always be in the same place.
• Retrograde or prograde --Orbits with an inclination angle of 90 ° or less.It orbits in the same direction as the rotation of the planet.
• Retrograde or prograde --Orbits with an inclination angle of 90 ° or more.It orbits in the direction opposite to the direction of rotation of the planet.Apart from sun-synchronous orbit, few satellites are put into retrograde orbit due to fuel problems.This is because when launching a rocket from the earth, the projectile has already obtained the same rotation speed as the latitude of the launch site.

Classification by eccentricity

• circular orbit - Orbital eccentricityIs 0, and the orbit is in the shape of a circle.
• Elliptical orbit --Orbits with an eccentricity greater than 0 and less than 1.Draw an ellipse.
  • Geostationary transfer orbit --An elliptical orbit with a perigee on a low earth orbit and a perigee on a geostationary orbit.
  • Molniya orbit --An elliptical orbit with an orbital inclination of 63.4 ° and an orbital period half that of sidereal time.
  • Tundra orbit --An elliptical orbit with an orbital inclination of 63.4 ° and an orbital period similar to that of sidereal time.
• Hyperbolic trajectory ――Has an eccentricity of 1 or moreOrbit.Space velocityIt has the above speed and shakes off the gravitational force of the celestial body.
• Parabolic trajectory --Eccentricity is 1Orbit..It has the same speed as the cosmic velocity and shakes off the gravitational force of the earth.If the velocity increases, it becomes a hyperbolic trajectory.
  • (English edition） (EO) --A parabolic trajectory in which an object moves away from the earth at cosmic velocity.
  • (English edition） --A parabolic trajectory in which an object approaches the earth at cosmic velocity.

Classification by periodicity

• Return orbit —— An orbit that orbits the planet several times in a day and returns to its original surface at the same time a day later.The rotation period of the planet is an integral multiple of the orbital period of the satellite.
  • Synchronous orbit (SO) --The rotation period of the planet and the satelliteRevolution cycleOrbits that are equal.From the perspective of ground observers, satellitesAnalemmaMove on.
    • Geosynchronous orbit (GEO) --Synchronous orbit around the earth.Altitude about 35,786 km.
      • Geostationary orbit (GSO) - Orbital inclinationIs 0 °Geosynchronous orbit..The satellite appears to be fixed in the sky to observers on the ground^[17].Arthur C. ClarkIn honor ofClark orbitAlso called.
      • Quasi-zenith orbit (QZO) --Orbital inclination andEccentricitySynchronous orbit that adjusts to stay in the sky above a specific area away from the equator for a long time.Asymmetric 8-shaped orbit, verticalDempsey rollAlso called an orbit.
      • Graveyard orbit --Orbits hundreds of kilometers above geosynchronous orbit.The satellite will move here at the end of the mission.
      • (English edition） --Drift orbit just below geosynchronous orbit / geosynchronous orbit.The satellite drifts east.
    • (English edition） --Synchronous orbit around Mars.The orbital period is on MarsSidereal timeEqual to (24.6229 hours).
      • (English edition） (ASO) --Mars synchronous orbit at an altitude of 1700 km on the equator of Mars.It corresponds to the geosynchronous orbit of the earth.
    • (English edition） --Synchronous orbit around the sun.The orbital radius is 0.1628AUAnd it is a little smaller than half the orbital radius of Mercury.
  • Semi-synchronous orbit (SSO) --Orbits whose orbital period is equal to half the rotation period of the planet.
• Semi-return orbit —— An orbit that orbits the earth several times in a day and does not return within that day, but returns to the original surface of the earth after a certain number of days.
• Sun-synchronous orbit —— An orbit in which the angle between the orbital surface of the artificial satellite and the sun's rays is always constant.Because sunlight is always available and the angle of the sun's rays is always constant with respect to the surface of the earth.Earth observation satelliteIs used for.

Pseudo orbit

• Horseshoe orbit ――From the viewpoint of the observer on the ground, it seems that it orbits around the planet where the observer is, but in reality, the observed object is a planet.(English edition）The orbit that is.Cruithne,2002 AA₂₉See.
• Exo orbit - OrbitIt was planned to reach, but the orbit fell due to insufficient speed.Ballistic flightSynonyms for.
• Hohmann transition orbit (LTO) - Propulsion deviceAn orbit that moves from a circular orbit to another circular orbit using twice.Walter HohmannIt was named after.
• Halo orbit/Lissajous orbit - Lagrange pointOrbit around.

Artificial satellite configuration

The artificial satellite system is "Satellite system"When"Ground support systemConsists of^[18], Between the twoUplinkとDownlinkIs done.The satellite system is a "satellite" for carrying out missions specific to that satellite.Mission equipment"Whenelectricity,communication,Attitude controlRequired for basic functions such as "Bus equipmentIt is composed of.In addition, the ground support system consists of equipment for tracking artificial satellites, acquiring data, and operating and controlling them.^[19].

Satellite bus department

TTC system

TTC is a telemetry (transmission of satellite operation status to the ground), tracking (transmission and reception of orbit measurement signals), and command (operation commands such as power on / off of equipment and mode switching).However, in recent years, the number of cases where commands are automatically transmitted by the installed computer is increasing, and the TTC system is called the C & DH system (command data handling system).^[19].

Power supply system

• Solar cell,battery,, consists of a power controller.The solar cell is mounted on the surface of the airframe or on the solar cell paddle.
• Once smallReactorHas been used for artificial satellites, but now it is almostSolar cellIs used.Also, without the solar cell,batteryThere are also only satellites.
• Solar cells may not be usable on space probes, but in that caseAtomic batteryPrepare an alternative power supply.

Posture control system

Artificial satellites are the strain of the earth's gravitational field, the attraction of the moon and the sun,Solar windThe attitude gradually changes due to minute forces other than the gravitational force of the earth, such as dilute air molecules.Posture stabilization is roughly divided into "spin attitude stabilization method" and "three-axis attitude stabilization method". The former was often used in the early stages of space development because it has a simple structure and does not require special equipment. The shape is limited to a cylinder, and the solar cell can only be attached to the surface of the cylinder.The latter has the advantage that the posture direction can be freely selected and a large vertical solar cell paddle can be attached, but it also has the disadvantage that thermal control becomes complicated.^[19].

Propulsion system

• Even if the satellite is put into the planned orbit, if it is left unattended, the earth'sGravity anomalyAndSolar windThe trajectory gradually changes due to the disturbance caused by.so that,ThrusterIs operated to control the orbit.
• Reconnaissance satelliteIn the case of, it is also used to make the necessary orbital changes for reconnaissance.
• Geostationary satellitein the case of,Geostationary transfer orbitからGeostationary orbitTo change the trajectory toApogee kick motorIs installed, but it also constitutes a propulsion system.
• It is also used to finally increase orbit altitude so that geostationary satellites have reached the end of their life and debris does not occupy valuable geostationary orbit.It can also be used to create a safe inrush orbit when an orbiting satellite falls to Earth.

Structure system

Satellites receive large loads, vibrations, and shocks during launch and separation.Therefore, it is necessary to design the airframe so as to reduce the burden on the on-board equipment.There are structures such as a central cylindrical type, a panel support type, and a truss type, and they may be composed of a composite of these.Where strength is required as a material,TitaniumEtc. are used^[19].

Thermal control system

Satellites are exposed to harsh high to low temperature environments in outer space.Also, in outer space, which is a vacuumradiationbyWaste heatThere is only.Therefore, in order for the mounted equipment to operate well, it is necessary to design it well so that it falls within the operating temperature.ActualhardwareWill be realized by making full use of the following means.

• --Insulation material.Suppress heat in and out.
• heat pipe --Transfer excessive heat dissipation from the heat source to the radiator.
• Radiator --A thermal radiator.
• heater --Warm the equipment so that it is not overcooled.

On geostationary satellitessummer solstice,winter solstice,spring equinox,Autumn equinoxUnder the conditions of, the condition of sunlight and from the earthradiationDesign analysis is performed using a finite element satellite structural model.

Mission department

Observation equipment

Observation equipment to realize the mission.For details, refer to the item of each artificial satellite.

transponder

transponderIs a device installed in the case of communication / broadcasting satellites.A transmitter / receiver that receives radio waves emitted from the ground, converts frequencies, amplifies high power, and sends them back to the ground.

Antenna system

antennaIs a gateway for radio waves and plays an important role in broadcasting / communication missions and radar observation satellites.

Ground control system

Satellite abandonment

As the satellite's mission nears completion, there are options to move the satellite out of its current orbit, leave it in place, or move it to graveyard orbit.Early artificial satellites rarely had the function of changing orbits due to budgetary reasons.For example1958/Was launched intoVanguard 1Is the fourth satellite put into orbit,2009/8It still exists in orbit and is the longest satellite in orbit.^[20].

Currently, satellites in geosynchronous orbit, including meteorological satellites, are equipped with thrusters to control attitude and orbit.When the thruster runs out of fuel, the satellite will not be able to maintain a geosynchronous orbit, so at the end of its life, it will be in a higher orbit from the geosynchronous orbit.Graveyard orbit),Stoppage·Discard.However, some of them could not get out of orbit for some reason,Space debrisSome satellites turn into^[21].AirbusEtc. are considering a service to catch and drop an old artificial satellite that cannot move^[22].

When dropping while controlling on the ground, it is on the South PacificPole of inaccessibility(Point Nemo) To drop^[23].

There are also plans to extend the life of the spacecraft by refueling and repairing it.^[24].

Countries / organizations that have successfully put artificial satellites into orbit

This list is the launch machine of your own country (Launch Vehicle) Is a list of countries that have succeeded in getting artificial satellites into orbit.Many countries have the ability to design and manufacture artificial satellites, but the countries that can launch artificial satellites with their own launch vehicles are2013/19 countries at the end (Russia,ウクライナ,America,Japan,Chugoku,India,Israel,(I.e.,north korea) And 1 institution (European Space Agency(ESA)) only, and the majority of countries will rely on these few countries and agencies for launch operations.

Launch capability by private organizations

• Orbital Sciences TheTaurus rocketWe are launching using.
• 2008/May 9, Commercial airlinesSpace x TheFalcon 1The rocket was successfully launched into orbit.This is the first time a privately built liquid fuel booster has reached orbit.^[25]..The rocket launched a 1.5 m long model into orbit.This dummy satellite called Ratsat burns out in the atmosphere in 5 to 10 years.^[25]..In addition, a small number of private companies are developing rockets capable of ballistic flight.
• Arianespace,Mitsubishi Heavy IndustriesEtc. have been transferred from the space agency to launch artificial satellites.

First artificial satellite by country

The country's first artificial satellite, including one from another country's rocket^[26]

Country / institution	first Launch year	First artificial satellite	Number of satellites in orbit[27] As of 2013 (2011)
Soviet Union ( Russia）	1957/ (1992)	Sputnik 1 (Cosmos 2175）	1,457 (1,446)
America	1958/	Explorer 1	1,110 (1,112)
United Kingdom	1962/	Ariel 1	0030 (28)
Canada	1962/	Alouette 1	0034 (32)
Italy	1964/	San Marco 1	0022 (18)
France	1965/	Asterix	0057 (49)
Australia	1967/	WRESAT	0013 (12)
Germany	1969/	Azul	0042 (41)
Japan	1970/	Osumi	0134 (126)
Chugoku	1970/	Toho Beni No. 1	0140 (117)
Netherlands	1974/	ANS	0013 (12)
Spain	1974/	INTASAT	0009 (9)
India	1975/	Ariyabata	0054 (49)
Indonesia	1976/	Palapa A1	0012 (11)
Czechoslovakia	1978/	Magion 1	0005
European Space Agency	1979/	(English edition）	0000Unknown (49)
Bulgaria	1981/	Bulgaria 1300	0001 (1)
Saudi Arabia	1985/	(English edition）	0012
Brazil	1985/	Brasilsat A1	0013 (12)
Mexico	1985/	(English edition）	0007 (8)
Sweden	1986/	Viking	0011 (13)
Israel	1988/	Ofeq 1	0011 (10)
Luxembourg	1988/	(English edition）	0005 (19)
Argentine	1990/	LUSAT	0009 (9)
Hong Kong	1990/	(English edition）	0009
Pakistan	1990/	(English edition）	0003 (3)
South Korea	1992/	Uribyeol No. 1	0011 (10)
Portugal	1993/	(English edition）	0001 (1)
Thailand	1993/	Thaicom 1	0007 (7)
Turkey	1994/	(English edition）	0008 (7)
ウクライナ	1995/	Sich-1	0006
Malaysia	1996/	(English edition）	0006
Norway	1997/	Thor No. 2	0003
フィリピン	1997/	Abira No. 2 (Mabhai No. 1)	0002
Egypt	1998/	(English edition）	0004
チリ	1998/	(English edition）	0002 (1)
Singapore	1998/	ST-1	0003
Republic of China	1999/	FORMOSAT-1	0008 (8)
Denmark	1999/	(English edition）	0004
South Africa	1999/	SUNSAT	0002
United Arab Emirates	2000/	Thuraya 1	0006 (5)
モロッコ	2001/	(English edition）	0001
アルジェリア	2002/	(English edition）	0002
Greece	2003/	(English edition）	0002
Eur-lex.europa.eu eur-lex.europa.eu	2003/		0004
(I.e.	2005/	Sina-1	0001
Eur-lex.europa.eu eur-lex.europa.eu	2006/	KazSat-1	0002
コロンビア	2007/	Libertad 1	0001
Eur-lex.europa.eu eur-lex.europa.eu	2008/	Vinasat-1	0001
ベネズエラ	2008/	Venesat-1	0001
Switzerland	2009/	Swiss cube [28]	0002
Poland[29]	2012/	(English edition）	0002 (1)
Hungary	2012/	MaSat-1 [30]	0005
ルーマニア	2012/	Goliath [31]	0001
ベ ラ ル ー シ	2012/	BKA (BelKA-2)	0000n / A
DPR Korea	2012/	Gwangmyeong Star No. 3 Unit 2 [32]	0001
アゼルバイジャン	2013/	(English edition）
Peru	2014/	(English edition）

Canada is the third country to make artificial satellites^[33]The launch was carried out by an American rocket at an American range.Australia was donated by the United StatesRedstoneAnd by the American support teamWRESATLaunched^[34].. ItalyNASAAlong with a trained Italian team in the United StatesWallops IslandからScout rocketLaunched using^[35].

Planning

•  バングラデシュIntentions to launch artificial satellite Bangaband by June 2017^[36][37].
•  CroatiaWill build an artificial satellite between 2013 and 2014^[38](* Additional information has not been confirmed as of July 2016).
•  Sri LankaOrders manufacturing and launch of communications satellites from China^[39].

Attack on satellite

In the early 21st century, satellites were used by military organizationspropagandaFrom purpose or military networkConfidential informationTo stealhackingIs receiving^[40][41].

Low earth orbit artificial satellites from the earthBallistic missileIt can be destroyed by.Russia, the United States, and China have conducted experiments on satellite destruction^[42].. In 2007, China launched its own meteorological satelliteFengyun No. XNUMX CDestroy^[42], February 2008, US Navy launches its own reconnaissance satelliteUS-193Is destroying^[43].

footnote

注 釈

Source

Related item

• rocket - Range - launch pad
• Artificial satellite observation
• International designator
• Satellite catalog number
• Spacesuit satellite
• List of artifacts leaving the solar system
• Atmospheric satellite
• (English edition）
• (English edition）
• (English edition）

外部 リンク

• J-Track 3D --A site that displays the orbits of currently active artificial satellites in 3D (NASA)
• Satellite Ground Tracks --Real-time satellite terrestrial tracking
• UCS Satellite Database --A satellite that is currently active.Update is fast.
• Current and Historical Launch Calendar --Launch calendar.
• Protect and use the earth from space with artificial satellites -JAXA
• "Artificial satellite』- Koto bank