Satellite

Last updated

NASA's Earth-observing fleet as of June 2019
A full-size model of the Earth observation satellite ERS 2 ERS 2.jpg
A full-size model of the Earth observation satellite ERS 2

In the context of spaceflight, a satellite is an object that has been intentionally placed into orbit. These objects are called artificial satellites to distinguish them from natural satellites such as Earth's Moon.

Contents

On 4 October 1957, the Soviet Union launched the world's first artificial satellite, Sputnik 1. Since then, about 8,900 satellites from more than 40 countries have been launched. According to a 2018 estimate, about 5,000 remained in orbit. Of those, about 1,900 were operational, while the rest had exceeded their useful lives and become space debris. Approximately 63% of operational satellites are in low Earth orbit, 6% are in medium-Earth orbit (at 20,000 km), 29% are in geostationary orbit (at 36,000 km) and the remaining 2% are in various elliptical orbits. In terms of countries with the most satellites, the United States has the most with 1,897 satellites, China is second with 412, and Russia third with 176. [1] A few large space stations, including the International Space Station, have been launched in parts and assembled in orbit. Over a dozen space probes have been placed into orbit around other bodies and become artificial satellites of the Moon, Mercury, Venus, Mars, Jupiter, Saturn, a few asteroids, [2] a comet and the Sun.

Satellites are used for many purposes. Among several other applications, they can be used to make star maps and maps of planetary surfaces, and also take pictures of planets they are launched into. Common types include military and civilian Earth observation satellites, communications satellites, navigation satellites, weather satellites, and space telescopes. Space stations and human spacecraft in orbit are also satellites.

Satellites can operate by themselves or as part of a larger system, a satellite formation or satellite constellation.

Satellite orbits vary greatly, depending on the purpose of the satellite, and are classified in a number of ways. Well-known (overlapping) classes include low Earth orbit, polar orbit, and geostationary orbit.

A launch vehicle is a rocket that places a satellite into orbit. Usually, it lifts off from a launch pad on land. Some are launched at sea from a submarine or a mobile maritime platform, or aboard a plane (see air launch to orbit).

Satellites are usually semi-independent computer-controlled systems. Satellite subsystems attend many tasks, such as power generation, thermal control, telemetry, attitude control, scientific instrumentation, communication, etc.

History

Konstantin Tsiolkovsky 1986 CPA 5712.jpg
Konstantin Tsiolkovsky
A 1949 issue of Popular Science depicts the idea of an "artificial moon" Popular Science May 1949.jpg
A 1949 issue of Popular Science depicts the idea of an "artificial moon"
Animation depicting the orbits of GPS satellites in medium Earth orbit. ConstellationGPS.gif
Animation depicting the orbits of GPS satellites in medium Earth orbit.
Sputnik 1: The first artificial satellite to orbit Earth. Sputnik asm.jpg
Sputnik 1: The first artificial satellite to orbit Earth.
1U CubeSat ESTCube-1, developed mainly by the students from the University of Tartu, carries out a tether deployment experiment in low Earth orbit. ESTCube-1 illustration.jpg
1U CubeSat ESTCube-1, developed mainly by the students from the University of Tartu, carries out a tether deployment experiment in low Earth orbit.

The first published mathematical study of the possibility of an artificial satellite was Newton's cannonball, a thought experiment by Isaac Newton to explain the motion of natural satellites, in his Philosophiæ Naturalis Principia Mathematica (1687). The first fictional depiction of a satellite being launched into orbit was a short story by Edward Everett Hale, "The Brick Moon" (1869). [3] [4] The idea surfaced again in Jules Verne's The Begum's Fortune (1879).

In 1903, Konstantin Tsiolkovsky (1857–1935) published Exploring Space Using Jet Propulsion Devices, which is the first academic treatise on the use of rocketry to launch spacecraft. He calculated the orbital speed required for a minimal orbit, and that a multi-stage rocket fueled by liquid propellants could achieve this.

In 1928, Herman Potočnik (1892–1929) published his sole book, The Problem of Space Travel – The Rocket Motor. He described the use of orbiting spacecraft for observation of the ground and described how the special conditions of space could be useful for scientific experiments.

In a 1945 Wireless World article, the English science fiction writer Arthur C. Clarke described in detail the possible use of communications satellites for mass communications. [5] He suggested that three geostationary satellites would provide coverage over the entire planet.

In May 1946, the United States Air Force's Project RAND released the Preliminary Design of an Experimental World-Circling Spaceship, which stated that "A satellite vehicle with appropriate instrumentation can be expected to be one of the most potent scientific tools of the Twentieth Century." [6] The United States had been considering launching orbital satellites since 1945 under the Bureau of Aeronautics of the United States Navy. Project RAND eventually released the report, but considered the satellite to be a tool for science, politics, and propaganda, rather than a potential military weapon. [7]

In 1946, American theoretical astrophysicist Lyman Spitzer proposed an orbiting space telescope. [8]

In February 1954 Project RAND released "Scientific Uses for a Satellite Vehicle", written by R.R. Carhart. [9] This expanded on potential scientific uses for satellite vehicles and was followed in June 1955 with "The Scientific Use of an Artificial Satellite", by H.K. Kallmann and W.W. Kellogg. [10]

In the context of activities planned for the International Geophysical Year (1957–58), the White House announced on 29 July 1955 that the U.S. intended to launch satellites by the spring of 1958. This became known as Project Vanguard. On 31 July, the Soviets announced that they intended to launch a satellite by the fall of 1957.

The first artificial satellite was Sputnik 1, launched by the Soviet Union on 4 October 1957 under the Sputnik program, with Sergei Korolev as chief designer. Sputnik 1 helped to identify the density of high atmospheric layers through measurement of its orbital change and provided data on radio-signal distribution in the ionosphere. The unanticipated announcement of Sputnik 1's success precipitated the Sputnik crisis in the United States and ignited the so-called Space Race within the Cold War.

Sputnik 2 was launched on 3 November 1957 and carried the first living passenger into orbit, a dog named Laika. [11]

In early 1955, following pressure by the American Rocket Society, the National Science Foundation, and the International Geophysical Year, the Army and Navy were working on Project Orbiter with two competing programs. The army used the Jupiter C rocket, while the civilian/Navy program used the Vanguard rocket to launch a satellite. Explorer 1 became the United States' first artificial satellite on 31 January 1958. [12]

In June 1961, three-and-a-half years after the launch of Sputnik 1, the United States Space Surveillance Network cataloged 115 Earth-orbiting satellites. [13]

Early satellites were constructed to unique designs. With advancements in technology, multiple satellites began to be built on single model platforms called satellite buses. The first standardized satellite bus design was the HS-333 geosynchronous (GEO) communication satellite launched in 1972. Beginning in 1997, FreeFlyer is a commercial off-the-shelf software application for satellite mission analysis, design and operations.

Currently the largest artificial satellite ever is the International Space Station. [14]

Tracking

Satellites can be tracked from Earth stations and also from other satellites.

Space Surveillance Network

The United States Space Surveillance Network (SSN), a division of the United States Strategic Command, has been tracking objects in Earth's orbit since 1957 when the Soviet Union opened the Space Age with the launch of Sputnik I. Since then, the SSN has tracked more than 26,000 objects. The SSN currently tracks more than 8,000-artificial orbiting objects. The rest have re-entered Earth's atmosphere and disintegrated, or survived re-entry and impacted the Earth. The SSN tracks objects that are 10 centimeters in diameter or larger; those now orbiting Earth range from satellites weighing several tons to pieces of spent rocket bodies weighing only 10 pounds. About seven percent are operational satellites (i.e. ~560 satellites), the rest are space debris. [15] The United States Strategic Command is primarily interested in the active satellites, but also tracks space debris which upon reentry might otherwise be mistaken for incoming missiles.

Services

There are three basic categories of (non-military) satellite services: [16]

Fixed satellite services

Fixed satellite services handle hundreds of billions of voice, data, and video transmission tasks across all countries and continents between certain points on the Earth's surface.

Mobile satellite systems

Mobile satellite systems help connect remote regions, vehicles, ships, people and aircraft to other parts of the world and/or other mobile or stationary communications units, in addition to serving as navigation systems.

Scientific research satellites (commercial and noncommercial)

Scientific research satellites provide meteorological information, land survey data (e.g. remote sensing), Amateur (HAM) Radio, and other different scientific research applications such as earth science, marine science, and atmospheric research.

Types

The Hubble Space Telescope HST-SM4.jpeg
The Hubble Space Telescope
International Space Station International Space Station after undocking of STS-132.jpg
International Space Station

Orbits

Various earth orbits to scale; cyan represents low earth orbit, yellow represents medium earth orbit, the black dashed line represents geosynchronous orbit, the green dash-dot line the orbit of Global Positioning System (GPS) satellites, and the red dotted line the orbit of the International Space Station (ISS). Orbits around earth scale diagram.svg
Various earth orbits to scale; cyan represents low earth orbit, yellow represents medium earth orbit, the black dashed line represents geosynchronous orbit, the green dash-dot line the orbit of Global Positioning System (GPS) satellites, and the red dotted line the orbit of the International Space Station (ISS).

The first satellite, Sputnik 1, was put into orbit around Earth and was therefore in geocentric orbit. This is the most common type of orbit by far, with approximately 3,372 [19] active artificial satellites orbiting the Earth. Geocentric orbits may be further classified by their altitude, inclination and eccentricity.

The commonly used altitude classifications of geocentric orbit are Low Earth orbit (LEO), Medium Earth orbit (MEO) and High Earth orbit (HEO). Low Earth orbit is any orbit below 2,000 km. Medium Earth orbit is any orbit between 2,000 and 35,786 km. High Earth orbit is any orbit higher than 35,786 km.

Centric classifications

Altitude classifications

Orbital Altitudes of several significant satellites of earth. Orbitalaltitudes.jpg
Orbital Altitudes of several significant satellites of earth.

Inclination classifications

Eccentricity classifications

Synchronous classifications

Special classifications

Pseudo-orbit classifications

Subsystems

The satellite's functional versatility is embedded within its technical components and its operations characteristics. Looking at the "anatomy" of a typical satellite, one discovers two modules. [16] Note that some novel architectural concepts such as Fractionated spacecraft somewhat upset this taxonomy.

Spacecraft bus or service module

The bus module consists of the following subsystems:

Structure

The structural subsystem provides the mechanical base structure with adequate stiffness to withstand stress and vibrations experienced during launch, maintain structural integrity and stability while on station in orbit, and shields the satellite from extreme temperature changes and micro-meteorite damage.

Telemetry

The telemetry subsystem (aka Command and Data Handling, C&DH) monitors the on-board equipment operations, transmits equipment operation data to the earth control station, and receives the earth control station's commands to perform equipment operation adjustments.

Power

The power subsystem may consist of solar panels to convert solar energy into electrical power, regulation and distribution functions, and batteries that store power and supply the satellite when it passes into the Earth's shadow. Nuclear power sources (Radioisotope thermoelectric generator) have also been used in several successful satellite programs including the Nimbus program (1964–1978). [21]

Thermal control

The thermal control subsystem helps protect electronic equipment from extreme temperatures due to intense sunlight or the lack of sun exposure on different sides of the satellite's body (e.g. optical solar reflector)

Attitude and orbit control

The attitude and orbit control subsystem consists of sensors to measure vehicle orientation, control laws embedded in the flight software, and actuators (reaction wheels, thrusters). These apply the torques and forces needed to re-orient the vehicle to the desired attitude, keep the satellite in the correct orbital position, and keep antennas pointed in the right directions.

Communications

The second major module is the communication payload, which is made up of transponders. A transponder is capable of :

End of life

When satellites reach the end of their mission (this normally occurs within 3 or 4 years after launch), satellite operators have the option of de-orbiting the satellite, leaving the satellite in its current orbit or moving the satellite to a graveyard orbit. Historically, due to budgetary constraints at the beginning of satellite missions, satellites were rarely designed to be de-orbited. One example of this practice is the satellite Vanguard 1. Launched in 1958, Vanguard 1, the 4th artificial satellite to be put in Geocentric orbit, was still in orbit as of March 2015, as well as the upper stage of its launch rocket. [22] [23]

Instead of being de-orbited, most satellites are either left in their current orbit or moved to a graveyard orbit. [24] As of 2002, the FCC requires all geostationary satellites to commit to moving to a graveyard orbit at the end of their operational life prior to launch. [25] In cases of uncontrolled de-orbiting, the major variable is the solar flux, and the minor variables the components and form factors of the satellite itself, and the gravitational perturbations generated by the Sun and the Moon (as well as those exercised by large mountain ranges, whether above or below sea level). The nominal breakup altitude due to aerodynamic forces and temperatures is 78 km, with a range between 72 and 84 km. Solar panels, however, are destroyed before any other component at altitudes between 90 and 95 km. [26]

Launch-capable countries

This list includes countries with an independent capability to place satellites in orbit, including production of the necessary launch vehicle. Note: many more countries have the capability to design and build satellites but are unable to launch them, instead relying on foreign launch services. This list does not consider those numerous countries, but only lists those capable of launching satellites indigenously, and the date this capability was first demonstrated. The list does not include the European Space Agency, a multi-national state organization, nor private consortiums.


First launch by country
OrderCountryDate of first launchRocketSatellite(s)
1 Soviet Union 4 October 1957 Sputnik-PS Sputnik 1
2 United States 1 February 1958 Juno I Explorer 1
3 France 26 November 1965 Diamant-A Astérix
4 Japan 11 February 1970 Lambda-4S Ohsumi
5 China 24 April 1970 Long March 1 Dong Fang Hong I
6 United Kingdom 28 October 1971 Black Arrow Prospero
7 India 18 July 1980 SLV Rohini D1
8 Israel 19 September 1988 Shavit Ofeq 1
[1] Russia 21 January 1992 Soyuz-U Kosmos 2175
[1] Ukraine 13 July 1992 Tsyklon-3 Strela
9 Iran 2 February 2009 Safir-1 Omid
10 North Korea 12 December 2012 Unha-3 Kwangmyŏngsŏng-3 Unit 2
11 South Korea 30 January 2013 Naro-1 STSAT-2C
12 New Zealand 12 November 2018 Electron CubeSat

Attempted first launches

Other notes

Launch capable private entities

Orbital Sciences Corporation launched a satellite into orbit on the Pegasus in 1990. SpaceX launched a satellite into orbit on the Falcon 1 in 2008. Rocket Lab launched three cubesats into orbit on the Electron in 2018.

First satellites of countries

.mw-parser-output .legend{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .legend-color{display:inline-block;min-width:1.25em;height:1.25em;line-height:1.25;margin:1px 0;text-align:center;border:1px solid black;background-color:transparent;color:black}.mw-parser-output .legend-text{}
orbital launch and satellite operation
satellite operation, launched by foreign supplier
satellite in development
orbital launch project at advanced stage or indigenous ballistic missiles deployed Space capabilities - launch and satellite.png
   orbital launch and satellite operation
  satellite operation, launched by foreign supplier
  satellite in development
   orbital launch project at advanced stage or indigenous ballistic missiles deployed

While Canada was the third country to build a satellite which was launched into space, [32] it was launched aboard an American rocket from an American spaceport. The same goes for Australia, who launched first satellite involved a donated U.S. Redstone rocket and American support staff as well as a joint launch facility with the United Kingdom. [33] The first Italian satellite San Marco 1 launched on 15 December 1964 on a U.S. Scout rocket from Wallops Island (Virginia, United States) with an Italian launch team trained by NASA. [34] By similar occasions, almost all further first national satellites was launched by foreign rockets.

Attempted first satellites

†-note: Both Chile and Belarus used Russian companies as principal contractors to build their satellites, they used Russian-Ukrainian manufactured rockets and launched either from Russia or Kazakhstan.

Planned first satellites

Attacks on satellites

Since the mid-2000s, satellites have been hacked by militant organizations to broadcast propaganda and to pilfer classified information from military communication networks. [55] [56]

For testing purposes, satellites in low earth orbit have been destroyed by ballistic missiles launched from earth. Russia, United States, China and India have demonstrated the ability to eliminate satellites. [57] In 2007 the Chinese military shot down an aging weather satellite, [57] followed by the US Navy shooting down a defunct spy satellite in February 2008. [58] On 27 March 2019 India shot down a live test satellite at 300 km altitude in 3 minutes. India became the fourth country to have the capability to destroy live satellites. [59] [60]

Jamming

Due to the low received signal strength of satellite transmissions, they are prone to jamming by land-based transmitters. Such jamming is limited to the geographical area within the transmitter's range. GPS satellites are potential targets for jamming, [61] [62] but satellite phone and television signals have also been subjected to jamming. [63] [64]

Also, it is very easy to transmit a carrier radio signal to a geostationary satellite and thus interfere with the legitimate uses of the satellite's transponder. It is common for Earth stations to transmit at the wrong time or on the wrong frequency in commercial satellite space, and dual-illuminate the transponder, rendering the frequency unusable. Satellite operators now have sophisticated monitoring that enables them to pinpoint the source of any carrier and manage the transponder space effectively. [ citation needed ]

Earth observation

During the last five decades, space agencies have sent thousands of space crafts, space capsules, or satellites to the universe. In fact, weather forecasters make predictions on the weather and natural calamities based on observations from these satellites. [65]

The National Aeronautics and Space Administration (NASA) [66] requested the National Academies to publish a report, "Earth Observations from Space; The First 50 Years of Scientific Achievements", in 2008. It described how the capability to view the whole globe simultaneously from satellite observations revolutionized studies about the planet Earth. This development brought about a new age of combined Earth sciences. The National Academies report concluded that continuing Earth observations from the galaxy are necessary to resolve scientific and social challenges in the future. [67]

NASA

The NASA introduced an Earth Observing System (EOS) [68] composed of several satellites, science component, and data system described as the Earth Observing System Data and Information System (EOSDIS). It disseminates numerous science data products as well as services designed for interdisciplinary education. EOSDIS data can be accessed online and accessed through File Transfer Protocol (FTP) and Hyper Text Transfer Protocol Secure (HTTPS). [69] Scientists and researchers perform EOSDIS science operations within a distributed platform of multiple interconnected nodes or Science Investigator-led Processing Systems (SIPS) and discipline-specific Distributed Active Archive Centers (DACCs). [70]

ESA

The European Space Agency [71] have been operating Earth Observation satellites since the launch of Meteosat 1 in November 1977. [72] ESA currently has plans to launch a satellite equipped with an artificial intelligence (AI) processor that will allow the spacecraft to make decisions on images to capture and data to transmit to the Earth. [73] BrainSat will use the Intel Myriad X vision processing unit (VPU). The launching will be scheduled in 2019. ESA director for Earth Observation Programs Josef Aschbacher made the announcement during the PhiWeek in November 2018. [74] This is the five-day meet that focused on the future of Earth observation. The conference was held at the ESA Center for Earth Observation in Frascati, Italy. [73] ESA also launched the PhiLab, referring to the future-focused team that works to harness the potentials of AI and other disruptive innovations. [75] Meanwhile, the ESA also announced that it expects to commence the qualification flight of the Space Rider space plane in 2021. This will come after several demonstration missions. [76] Space Rider is the sequel of the Agency's Intermediate Experimental vehicle (IXV) which was launched in 2015. It has the capacity payload of 800 kilograms for orbital missions that will last a maximum of two months. [77]

Pollution and regulation

Generally liability has been covered by the Liability Convention. Issues like space debris, radio and light pollution are increasing in magnitude and at the same time lack progress in national or international regulation. [78] With future increase in numbers of satellite constellations, like SpaceX Starlink, it is feared especially by the astronomical community, such as the IAU, that orbital pollution will increase significantly. [79] [80] A report from the SATCON1 workshop in 2020 concluded that the effects of large satellite constellations can severely affect some astronomical research efforts and lists six ways to mitigate harm to astronomy. [81] [82] Some notable satellite failures that polluted and dispersed radioactive materials are Kosmos 954, Kosmos 1402 and the Transit 5-BN-3. Using wood as an alternative material has been posited in order to reduce pollution and debris from satellites that reenter the atmosphere. [83]

Open source satellites

Several open source satellites both in terms of open source hardware and open source software were flown or are in development. The satellites have usually form of a CubeSat or PocketQube. In 2013 an amateur radio satellite OSSI-1 was launched and remained in orbit for about 2 months. [84] In 2017 UPSat created by the Greek University of Patras and Libre Space Foundation remained in orbit for 18 months. In 2019 FossaSat-1 was launched. [85] [86] [87] [88] As of February 2021 the Portland State Aerospace Society is developing two open source satellites called OreSat [89] [90] and the Libre Space Foundation also has ongoing satellite projects. [91] [92] [93]

Satellite services

See also

Related Research Articles

Spacecraft Vehicle or machine designed to fly in outer space

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.

Geosynchronous orbit Orbit keeping the satellite at a fixed longitude above the equator

A geosynchronous orbit is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds. 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 35,786 km (22,236 mi), and all geosynchronous orbits share that semi-major axis.

Geostationary orbit Circular orbit above the Earths equator and following the direction of the Earths rotation

A geostationary orbit, also referred to as a geosynchronous equatorial orbit (GEO), is a circular geosynchronous orbit 35,786 kilometres in altitude above Earth's equator and following the direction of Earth's rotation.

Earth observation satellite Satellite specifically designed to observe Earth from orbit

An Earth observation satellite or Earth remote sensing satellite is a satellite used or designed for Earth observation (EO) from orbit, including spy satellites and similar ones intended for non-military uses such as environmental monitoring, meteorology, cartography and others. The most common type are Earth imaging satellites, that take satellite images, analogous to aerial photographs; some EO satellites may perform remote sensing without forming pictures, such as in GNSS radio occultation.

Robotic spacecraft uncrewed spacecraft, usually under telerobotic control

A robotic spacecraft is an uncrewed spacecraft, usually under telerobotic control. A robotic spacecraft designed to make scientific research measurements is often called a space probe. Many space missions are more suited to telerobotic rather than crewed operation, due to lower cost and lower risk factors. In addition, some planetary destinations such as Venus or the vicinity of Jupiter are too hostile for human survival, given current technology. Outer planets such as Saturn, Uranus, and Neptune are too distant to reach with current crewed spacecraft technology, so telerobotic probes are the only way to explore them.

Mars 2MV-4 No.1 also known as Sputnik 22 in the West, was a Soviet spacecraft, which was launched in 1962 as part of the Mars programme, and was intended to make a flyby of Mars, and transmit images of the planet back to Earth. Due to a problem with the rocket which launched it, it was destroyed in low Earth orbit. It was the first of two Mars 2MV-4 spacecraft to be launched, the other being the Mars 1 spacecraft which was launched eight days later.

Project Vanguard was a program managed by the United States Naval Research Laboratory (NRL), which intended to launch the first artificial satellite into Earth orbit using a Vanguard rocket as the launch vehicle from Cape Canaveral Missile Annex, Florida.

Geostationary transfer orbit

A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites which are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step for reaching their final orbit.

Guiana Space Centre French and European spaceport near Kourou in French Guiana, operational since 1968

The Guiana Space Centre also called Europe's Spaceport is a French and European spaceport to the northwest of Kourou in French Guiana, a region of France in South America. Operational since 1968, it is particularly suitable as a location for a spaceport. It fulfills the two major geographical requirements of such a site:

Space debris Pollution around Earth by defunct artificial objects

Space debris is defunct artificial objects in space—principally in Earth orbit—which no longer serve a useful function. These include derelict spacecraft—nonfunctional spacecraft and abandoned launch vehicle stages—mission-related debris, and particularly numerous in Earth orbit, fragmentation debris from the breakup of derelict rocket bodies and spacecraft. In addition to derelict man-made objects left in orbit, other examples of space debris include fragments from their disintegration, erosion and collisions or even paint flecks, solidified liquids expelled from spacecraft, and unburned particles from solid rocket motors. Space debris represents a risk to spacecraft.

A geocentric orbit or Earth orbit involves any object orbiting the Earth, such as the Moon or artificial satellites. In 1997 NASA estimated there were approximately 2,465 artificial satellite payloads orbiting the Earth and 6,216 pieces of space debris as tracked by the Goddard Space Flight Center. Over 16,291 previously launched objects have decayed into the Earth's atmosphere.

Graveyard orbit Supersynchronous orbit where spacecraft are intentionally placed at the end of their operational life

A graveyard orbit, also called a junk orbit or disposal orbit, is an orbit that lies away from common operational orbits. One significant graveyard orbit is a supersynchronous orbit well above geosynchronous orbit. Some satellites are moved into such orbits at the end of their operational life to reduce the probability of colliding with operational spacecraft and generating space debris.

A supersynchronous orbit is either an orbit with a period greater than that of a synchronous orbit, or just an orbit whose apoapsis is higher than that of a synchronous orbit. A synchronous orbit has a period equal to the rotational period of the body which contains the barycenter of the orbit.

Outline of space exploration Overview of and topical guide to space exploration

The following outline is provided as an overview of and topical guide to space exploration:

Spacecraft collision avoidance is the implementation and study of processes minimizing the chance of orbiting spacecraft inadvertently colliding with other orbiting objects. The most common subject of spacecraft collision avoidance research and development is for human-made satellites in geocentric orbits. The subject includes procedures designed to prevent the accumulation of space debris in orbit, analytical methods for predicting likely collisions, and avoidance procedures to maneuver offending spacecraft away from danger.

CryoSat-2 European Space Agency environmental research satellite

CryoSat-2 is a European Space Agency environmental research satellite which was launched in April 2010. It provides scientists with data about the polar ice caps and tracks changes in the thickness of the ice with a resolution of about 1.3 centimetres.

Space research Scientific studies carried out using scientific equipment in outer space

Space research is scientific study carried out in outer space, and by studying outer space. From the use of space technology to the observable universe, space research is a wide research field. Earth science, materials science, biology, medicine, and physics all apply to the space research environment. The term includes scientific payloads at any altitude from deep space to low Earth orbit, extended to include sounding rocket research in the upper atmosphere, and high-altitude balloons.

References

  1. "UCS Satellite Database". ucsusa. 1 January 2021. Retrieved 30 March 2021.
  2. "NASA Spacecraft Becomes First to Orbit a Dwarf Planet". NASA. 6 March 2015.
  3. "Rockets in Science Fiction (Late 19th Century)". Marshall Space Flight Center. Archived from the original on 1 September 2000. Retrieved 21 November 2008.
  4. Bleiler, Everett Franklin; Bleiler, Richard (1991). Science-fiction, the Early Years . Kent State University Press. p.  325. ISBN   978-0-87338-416-2.
  5. Rhodes, Richard (2000). Visions of Technology. Simon & Schuster. p. 160. ISBN   978-0-684-86311-5.
  6. "Preliminary Design of an Experimental World-Circling Spaceship". RAND . July 1946. Retrieved 6 March 2008.
  7. Rosenthal, Alfred (1968). Venture into Space: Early Years of Goddard Space Flight Center. NASA. p. 15.
  8. "Hubble Essentials: About Lyman Spitzer, Jr". Hubble Site.
  9. R.R. Carhart, Scientific Uses for a Satellite Vehicle, Project RAND Research Memorandum. (Rand Corporation, Santa Monica) 12 February 1954.
  10. 2. H.K Kallmann and W.W. Kellogg, Scientific Use of an Artificial Satellite, Project RAND Research Memorandum. (Rand Corporation, Santa Monica) 8 June 1955.
  11. Gray, Tara; Garber, Steve (2 August 2004). "A Brief History of Animals in Space". NASA.
  12. Chang, Alicia (30 January 2008). "50th anniversary of first U.S. satellite launch celebrated". San Francisco Chronicle. Associated Press. Archived from the original on 1 February 2008.
  13. Portree, David S. F.; Loftus, Jr, Joseph P. (1999). "Orbital Debris: A Chronology" (PDF). Lyndon B. Johnson Space Center . p. 18. Archived from the original (PDF) on 1 September 2000. Retrieved 21 November 2008.
  14. Welch, Rosanne; Lamphier, Peg A. (22 February 2019). Technical Innovation in American History: An Encyclopedia of Science and Technology [3 volumes]. ABC-CLIO. p. 126. ISBN   978-1-61069-094-2.
  15. "Orbital Debris Education Package" (PDF). Lyndon B. Johnson Space Center. Archived from the original (PDF) on 8 April 2008. Retrieved 6 March 2008.
  16. 1 2 Grant, A.; Meadows, J. (2004). Communication Technology Update (ninth ed.). Focal Press. p.  284. ISBN   978-0-240-80640-2.
  17. "Workshop on the Use of Microsatellite Technologies" (PDF). United Nations. 2008. p. 6. Retrieved 6 March 2008.
  18. "Earth Observations from Space" (PDF). National Academy of Sciences. 2007. Archived from the original (PDF) on 12 November 2007.
  19. 1 2 "UCS Satellite Database". Union of Concerned Scientists. 1 August 2020. Retrieved 15 October 2020.
  20. Oberg, James (July 1984). "Pearl Harbor in Space". Omni . pp. 42–44.
  21. Schmidt, George; Houts, Mike (16 February 2006). "Radioisotope-based Nuclear Power Strategy for Exploration Systems Development" (PDF). STAIF Nuclear Symposium. 813: 334–339. Bibcode:2006AIPC..813..334S. doi:10.1063/1.2169210.
  22. "Vanguard 1 – Satellite Information". Satellite database. Heavens-Above. Retrieved 7 March 2015.
  23. "Vanguard 1 Rocket – Satellite Information". Satellite database. Heavens-Above. Retrieved 7 March 2015.
  24. "Conventional Disposal Method: Rockets and Graveyard Orbits". Tethers.
  25. "FCC Enters Orbital Debris Debate". Space.com. Archived from the original on 24 July 2009.
  26. "Object SL-8 R/B – 29659U – 06060B". Forecast for Space Junk Reentry. Satview. 11 March 2014.
  27. "UNMOVIC report" (PDF). United Nations Monitoring, Verification and Inspection Commission. p. 434 ff.
  28. "Deception Activities – Iraq Special Weapons". FAS. Archived from the original on 22 April 1999.
  29. "Al-Abid LV".
  30. The video tape of a partial launch attempt which was retrieved by UN weapons inspectors later surfaced showing that the rocket prematurely exploded 45 seconds after its launch. [27] [28] [29]
  31. Myers, Steven Lee (15 September 1998). "U.S. Calls North Korean Rocket a Failed Satellite". The New York Times. Archived from the original on 9 December 2018. Retrieved 9 September 2019.
  32. Burleson, Daphne (2005). Space Programs Outside the United States. McFarland & Company. p. 43. ISBN   978-0-7864-1852-7.
  33. Mike Gruntman (2004). Blazing the Trail. American Institute of Aeronautics and Astronautics. p. 426. ISBN   978-1-56347-705-8.
  34. Harvey, Brian (2003). Europe's Space Programme. Springer Science+Business Media. p. 114. ISBN   978-1-85233-722-3.
  35. "North Korea says it successfully launched controversial satellite into orbit". NBC News. 12 December 2012.
  36. Wissam Said Idrissi. "Libsat – Libyan Satellite Project". libsat.ly.
  37. "Satellite department to be set up in Armenia's national telecommunication center". arka.am.
  38. "Canada's MDA Ready to Help Armenia Launch First Comsat". Asbarez News. 9 August 2013.
  39. "China keen on Armenian satellite launch project". arka.am.
  40. "Royal Group receives right to launch first Cambodia satellite". 19 April 2011.
  41. "China to launch second African satellite-Science-Tech-chinadaily.com.cn". China Daily.
  42. "Vremenik". Astronautica.
  43. Bray, Allison (1 December 2012). "Students hope to launch first ever Irish satellite". The Independent. Ireland.
  44. "Наши публикации". ComelPro.
  45. "Burma to launch first state-owned satellite, expand communications". News. Mizzima. 14 June 2011. Archived from the original on 17 June 2011.
  46. "Nicaragua says Nicasat-1 satellite still set for 2016 launch". telecompaper.com.
  47. Zachary Volkert (26 December 2013). "Paraguay to vote on aerospace agency bill in 2014". BNamericas.
  48. "Why a little country like Paraguay is launching a space program". GlobalPost.
  49. "SSTL Contracted to Establish Sri Lanka Space Agency". Satellite Today. Retrieved 28 November 2009.
  50. "SSTL contracted to establish Sri Lanka Space Agency". Adaderana. Retrieved 28 November 2009.
  51. "Syria on the Internet". souria.com. Archived from the original on 3 April 2015.
  52. Hamrouni, C.; Neji, B.; Alimi, A. M.; Schilling, K. (2009). 2009 4th International Conference on Recent Advances in Space Technologies. Explore. IEEE. pp. 750–755. doi:10.1109/RAST.2009.5158292. ISBN   978-1-4244-3626-2. S2CID   34741975.
  53. "Uzbekistan Planning First Satellite". Sat News. 18 May 2001. Archived from the original on 13 July 2001.
  54. "Uzbekistan Planning to Launch Two Satellites With Russian Help". Red Orbit. 8 June 2004. Archived from the original on 12 January 2012.
  55. Morrill, Dan. "Hack a Satellite while it is in orbit". ITtoolbox. Archived from the original on 20 March 2008. Retrieved 25 March 2008.
  56. "AsiaSat accuses Falungong of hacking satellite signals". Press Trust of India. 22 November 2004.
  57. 1 2 Broad, William J.; Sanger, David E. (18 January 2007). "China Tests Anti-Satellite Weapon, Unnerving U.S." The New York Times .
  58. "Navy Missile Successful as Spy Satellite Is Shot Down". Popular Mechanics . 2008. Retrieved 25 March 2008.
  59. "India successfully tests anti-satellite weapon: Modi". The Week. Retrieved 27 March 2019.
  60. Diplomat, Harsh Vasani, The. "India's Anti-Satellite Weapons". The Diplomat. Retrieved 27 March 2019.
  61. Singer, Jeremy (2003). "U.S.-Led Forces Destroy GPS Jamming Systems in Iraq". Space.com. Archived from the original on 26 May 2008. Retrieved 25 March 2008.
  62. Brewin, Bob (2003). "Homemade GPS jammers raise concerns". Computerworld . Archived from the original on 22 April 2008. Retrieved 25 March 2008.
  63. "Iran government jamming exile satellite TV". Iran Focus . 2008. Retrieved 25 March 2008.
  64. Selding, Peter de (2007). "Libya Pinpointed as Source of Months-Long Satellite Jamming in 2006". Space.com. Archived from the original on 29 April 2008.
  65. "Earth Observations from Space " Earth Observations from Space". nas-sites.org. Retrieved 28 November 2018.
  66. "Home | The National Academies of Sciences, Engineering, and Medicine | National-Academies.org | Where the Nation Turns for Independent, Expert Advice". www.nationalacademies.org. Retrieved 28 November 2018.
  67. Council, National Research (17 December 2008). Earth Observations from Space. doi:10.17226/11991. ISBN   978-0-309-11095-2.
  68. "About EOSDIS | Earthdata". earthdata.nasa.gov. Retrieved 28 November 2018.
  69. "Earth Observation Data | Earthdata". earthdata.nasa.gov. Retrieved 28 November 2018.
  70. "EOSDIS Distributed Active Archive Centers (DAACs) | Earthdata". earthdata.nasa.gov. Retrieved 28 November 2018.
  71. esa. "ESA". European Space Agency. Retrieved 28 November 2018.
  72. "50 years of Earth Observation". ESA. Retrieved 21 August 2019.
  73. 1 2 "ESA preps Earth observation satellite with onboard AI processor". SpaceNews.com. 13 November 2018. Retrieved 28 November 2018.
  74. "Movidius Myriad X VPU | Intel Newsroom". Intel Newsroom. Retrieved 28 November 2018.
  75. "The ESA Earth Observation Φ-week EO Open Science and FutureEO". phiweek.esa.int. Retrieved 28 November 2018.
  76. "ESA targets 2021 for Space Rider demo flight". SpaceNews.com. 13 November 2018. Retrieved 28 November 2018.
  77. esa. "IXV". European Space Agency. Retrieved 28 November 2018.
  78. "Problem Weltraumschrott: Die kosmische Müllkippe – Wissenschaft". Der Spiegel. Retrieved 22 April 2017.
  79. "IAU's statement on satellite constellations". International Astronomical Union. Retrieved 3 June 2019.
  80. "Light pollution from satellites will get worse. But how much?". astronomy.com. 14 June 2019.
  81. Zhang, Emily. "SpaceX's Dark Satellites Are Still Too Bright for Astronomers". Scientific American. Retrieved 16 September 2020.
  82. "Report Offers Roadmap to Mitigate Effects of Large Satellite Constellations on Astronomy | American Astronomical Society". aas.org. Retrieved 16 September 2020.
  83. Harper, Justin (29 December 2020). "Japan developing wooden satellites to cut space junk". bbc.co.uk. Retrieved 29 December 2020.
  84. "ossicode - Overview". GitHub. Retrieved 27 February 2021.
  85. Kulu, Erik. "FossaSat-1 @ Nanosats Database". Nanosats Database. Retrieved 27 February 2021.
  86. "FossaSat 1, 1b". Gunter's Space Page. Retrieved 27 February 2021.
  87. "FossaSat-1, an Open Source Satellite for the Internet of Things". Hackster.io. Retrieved 27 February 2021.
  88. FOSSASystems/FOSSASAT-1, FOSSA Systems, 24 February 2021, retrieved 27 February 2021
  89. "oresat". www.oresat.org. Retrieved 27 February 2021.
  90. "Oregon Small Satellite Project". GitHub. Retrieved 27 February 2021.
  91. "PocketQubes". Libre Space Foundation. Retrieved 27 February 2021.
  92. "QUBIK". Libre Space Foundation. Retrieved 27 February 2021.
  93. "Qubik". GitLab. Retrieved 27 February 2021.

Further reading