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82-520: The Kwangmyŏngsŏng program was a class of experimental satellites developed by North Korea . The name Kwangmyŏngsŏng ("bright star", "brilliant star" or "constellation" in Korean ) is from a poem written by Kim Il Sung . The first class of satellites built by North Korea, the program started in the mid-1980s. There have been five launches so far, of which two have been successful. According to North Korea Academy of Science's Academician Kwon Tong-hwa,
164-591: A Diamant A rocket launched from the CIEES site at Hammaguir , Algeria . With Astérix, France became the sixth country to have an artificial satellite. Early satellites were built 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
246-414: A catalyst . The most commonly used propellant mixtures on satellites are hydrazine -based monopropellants or monomethylhydrazine – dinitrogen tetroxide bipropellants. Ion thrusters on satellites usually are Hall-effect thrusters , which generate thrust by accelerating positive ions through a negatively-charged grid. Ion propulsion is more efficient propellant-wise than chemical propulsion but its thrust
328-813: A halo orbit , three for a Lissajous orbit ). Earth observation satellites gather information for reconnaissance , mapping , monitoring the weather , ocean, forest, etc. Space telescopes take advantage of outer space's near perfect vacuum to observe objects with the entire electromagnetic spectrum . Because satellites can see a large portion of the Earth at once, communications satellites can relay information to remote places. The signal delay from satellites and their orbit's predictability are used in satellite navigation systems, such as GPS. Space probes are satellites designed for robotic space exploration outside of Earth, and space stations are in essence crewed satellites. The first artificial satellite launched into
410-409: A transponder ; it creates a communication channel between a source transmitter and a receiver at different locations on Earth . Communications satellites are used for television , telephone , radio , internet , and military applications. Many communications satellites are in geostationary orbit 22,236 miles (35,785 km) above the equator , so that the satellite appears stationary at
492-591: A Satellite Vehicle", by R. R. Carhart. 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. 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
574-453: A U.S. Scout rocket from Wallops Island (Virginia, United States) with an Italian launch team trained by NASA . In similar occasions, almost all further first national satellites were launched by foreign rockets. France was the third country to launch a satellite on its own rocket. On 26 November 1965, the Astérix or A-1 (initially conceptualized as FR.2 or FR-2), was put into orbit by
656-405: A bandwidth of tens of megahertz. Satellites are placed from the surface to the orbit by launch vehicles , high enough to avoid orbital decay by the atmosphere . Satellites can then change or maintain the orbit by propulsion , usually by chemical or ion thrusters . As of 2018, about 90% of the satellites orbiting the Earth are in low Earth orbit or geostationary orbit ; geostationary means
738-645: A delivery device such as a missile, rather than to attain the destructive power of a true hydrogen bomb. North Korea had previously conducted three underground nuclear tests in 2006 , 2009 , and 2013 , drawing sanctions from the United Nations Security Council . The presidents of the United States and South Korea urged North Korea to rejoin the six-party talks in October 2015. The presidents also warned North Korea against
820-492: A fourth nuclear test. In December 2015 North Korean supreme leader Kim Jong Un suggested that the country had the capacity to launch a hydrogen bomb , a device of considerably more power than conventional atomic bombs used in previous tests. The remark was met with skepticism from the White House and South Korean officials. Around this time, the country approached the United States about possible peace talks to end
902-409: A generally lower kiloton yield and are mostly weapons used for specific purposes such as atomic demolition munitions . Tritium boosting is relatively easy to implement and has advantages in yield, weight, size, safety (zero or negligible yield when the tritium is not in the weapon), resistance to spontaneous fission caused by other warheads and high transparency to X-rays. Jeffrey Lewis , expert at
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#1732780697497984-466: A launch site in Musudan-ri , Hwadae -gun, North Hamgyong Province by a Paektusan-1 satellite launch vehicle (SLV). No objects were ever tracked in orbit from the launch, and outside North Korea it is considered to have been a failure. United States Space Command reported that the satellite failed to reach orbit, and burned up in the atmosphere. The failure is believed to have occurred during
1066-402: A little bit more efficient fission weapon – or the hydrogen part of the test really didn't work very well, or the fission part didn't work very well." After considering the seismic data which suggests a 6–9 kiloton yield, other U.S. analysts also do not believe that a hydrogen bomb was detonated. "What we're speculating is they tried to do a boosted nuclear device, which is an atomic bomb that has
1148-613: A little bit of hydrogen, an isotope in it called tritium," said Joseph Cirincione , president of the global security firm Ploughshares Fund . On the other hand, John Carlson, a member of the Nuclear Fuel Cycle Royal Commission and former head of the Australian Safeguards and Non-Proliferation Office declared previous North Korean tests were purely a primary stage, that is, a nuclear explosion, "and fairly low yield at that". However, in
1230-484: A method of communication to ground stations , called transponders . Many satellites use a standardized bus to save cost and work, the most popular of which are small CubeSats . Similar satellites can work together as groups, forming constellations . Because of the high launch cost to space, most satellites are designed to be as lightweight and robust as possible. Most communication satellites are radio relay stations in orbit and carry dozens of transponders, each with
1312-418: A satellite's lifetime. Resource use is difficult to monitor and quantify for satellites and launch vehicles due to their commercially sensitive nature. However, aluminium is a preferred metal in satellite construction due to its lightweight and relative cheapness and typically constitutes around 40% of a satellite's mass. Through mining and refining, aluminium has numerous negative environmental impacts and
1394-594: A second version of Kwangmyongsong-3 to be lifted by a Unha-3 carrier rocket at the Sohae Satellite Launching Station on a launch period between 10 and 22 December 2012. The launch was carried out on 12 December 2012, at 09:50 local time (00:50 UTC) and the satellite entered polar orbit, as confirmed by monitoring agencies in South Korea and North America with NORAD #39026 and International designator 2012-072A. Kwangmyongsong-4 or KMS-4
1476-449: A thin cable called a tether . Recovery satellites are satellites that provide a recovery of reconnaissance, biological, space-production and other payloads from orbit to Earth. Biosatellites are satellites designed to carry living organisms, generally for scientific experimentation. Space-based solar power satellites are proposed satellites that would collect energy from sunlight and transmit it for use on Earth or other places. Since
1558-600: 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). 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
1640-577: A warhead for shorter-range missiles, but not yet for intercontinental ballistic missiles, or ICBMs. There is a clear distinction between first- and second-generation nuclear weapons, i.e. atomic and hydrogen bombs. However, virtually all second generation bombs use a few grams of deuterium-tritium gas to ensure the reliability and safety of the nuclear fission-explosives. They can then be used on their own as boosted fission bombs or as primaries of two-stage thermonuclear (hydrogen) weapons. Weapons which in contemporary arsenals do not use tritium boosting have
1722-511: A yield of 6–9 kilotons of TNT and Russian estimates of more than 7 kilotons of TNT). Won-Young Kim at the Lamont–Doherty Earth Observatory explained it "was more powerful than North Korea's previous nuclear test" and added that it is difficult to quantify "the exact size of North Korea's nuclear detonations because the depth of the explosive device, properties of the rock surrounding the explosion and other factors influence
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#17327806974971804-400: Is a commercial off-the-shelf software application for satellite mission analysis, design, and operations. After the late 2010s, and especially after the advent and operational fielding of large satellite internet constellations —where on-orbit active satellites more than doubled over a period of five years—the companies building the constellations began to propose regular planned deorbiting of
1886-540: Is an Earth observation satellite launched by North Korea on 7 February 2016. On 7 February 2016, roughly a month after an alleged hydrogen bomb test , North Korea claimed to have put a satellite into orbit around the Earth . Japanese Prime Minister Shinzō Abe had warned the North to not launch the rocket, and if it did and the rocket violated Japanese territory, it would be shot down. Nevertheless, North Korea launched
1968-721: Is an object, typically a spacecraft , placed into orbit around a celestial body . They have a variety of uses, including communication relay, weather forecasting , navigation ( GPS ), broadcasting , scientific research, and Earth observation. Additional military uses are reconnaissance, early warning , signals intelligence and, potentially, weapon delivery. Other satellites include the final rocket stages that place satellites in orbit and formerly useful satellites that later become defunct. Except for passive satellites , most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope thermoelectric generators (RTGs). Most satellites also have
2050-610: Is currently unclear. The visibility of man-made objects in the night sky may also impact people's linkages with the world, nature, and culture. At all points of a satellite's lifetime, its movement and processes are monitored on the ground through a network of facilities. The environmental cost of the infrastructure as well as day-to-day operations is likely to be quite high, but quantification requires further investigation. Particular threats arise from uncontrolled de-orbit. Some notable satellite failures that polluted and dispersed radioactive materials are Kosmos 954 , Kosmos 1402 and
2132-399: Is dependent on rocket design and fuel type. The amount of green house gases emitted by rockets is considered trivial as it contributes significantly less, around 0.01%, than the aviation industry yearly which itself accounts for 2-3% of the total global greenhouse gas emissions. Rocket emissions in the stratosphere and their effects are only beginning to be studied and it is likely that
2214-473: Is deployed for military or intelligence purposes, it is known as a spy satellite or reconnaissance satellite. Their uses include early missile warning, nuclear explosion detection, electronic reconnaissance, and optical or radar imaging surveillance. Navigational satellites are satellites that use radio time signals transmitted to enable mobile receivers on the ground to determine their exact location. The relatively clear line of sight between
2296-517: Is most used in archaeology , cartography , environmental monitoring , meteorology , and reconnaissance applications. As of 2021, there are over 950 Earth observation satellites, with the largest number of satellites operated with Planet Labs . Weather satellites monitor clouds , city lights , fires , effects of pollution , auroras , sand and dust storms , snow cover, ice mapping, boundaries of ocean currents , energy flows, etc. Environmental monitoring satellites can detect changes in
2378-581: Is one of the most carbon-intensive metals. Satellite manufacturing also requires rare elements such as lithium , gold , and gallium , some of which have significant environmental consequences linked to their mining and processing and/or are in limited supply. Launch vehicles require larger amounts of raw materials to manufacture and the booster stages are usually dropped into the ocean after fuel exhaustion. They are not normally recovered. Two empty boosters used for Ariane 5 , which were composed mainly of steel, weighed around 38 tons each, to give an idea of
2460-430: Is the chemical propellant used which then releases ammonia , hydrogen and nitrogen as gas into the upper atmosphere. Also, the environment of the outer atmosphere causes the degradation of exterior materials. The atomic oxygen in the upper atmosphere oxidises hydrocarbon-based polymers like Kapton , Teflon and Mylar that are used to insulate and protect the satellite which then emits gasses like CO 2 and CO into
2542-478: Is used in essentially all militarized nuclear weapons, including in India, Pakistan, and North Korea". Quick estimates of the impact of such a weapon "detonated 1,000 meters over downtown Seoul would produce 78,000 fatalities and somewhere around 270,000 estimated injuries", according to Ryan Faith of ViceNews . Analyst Zack Beauchamp of Vox points out that yield and technology in this test "won't fundamentally change
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2624-425: Is very small (around 0.5 N or 0.1 lb f ), and thus requires a longer burn time. The thrusters usually use xenon because it is inert , can be easily ionized , has a high atomic mass and storable as a high-pressure liquid. Most satellites use solar panels to generate power, and a few in deep space with limited sunlight use radioisotope thermoelectric generators . Slip rings attach solar panels to
2706-849: The American Rocket Society , the National Science Foundation , and the International Geophysical Year, the Army and Navy worked 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. The information sent back from its radiation detector led to
2788-586: The Chinese military shot down an aging weather satellite, followed by the US Navy shooting down a defunct spy satellite in February 2008. On 18 November 2015, after two failed attempts, Russia successfully carried out a flight test of an anti-satellite missile known as Nudol . On 27 March 2019, India shot down a live test satellite at 300 km altitude in 3 minutes, becoming the fourth country to have
2870-476: The Korean War . In a New Year's Day speech, Kim Jong Un warned that provocation from "invasive outsiders" would be met with a "holy war of justice". The North Korean government described the test as a "complete success" and characterized it as self-defense against the United States. North Korean media claimed that the bomb was made the month before the test was carried out. Official state media from
2952-477: The Korean Workers' Party Central Committee , Kim Il Sung expressed his desire to quickly place a satellite into orbit, leading to the expansion of North Korea's nascent space program and the requirement for a space launch vehicle. The official Korean Central News Agency announced on 4 September 1998, Juche 87, that a satellite called Kwangmyŏngsŏng-1 had been launched at 3:07 UTC on 31 August from
3034-627: The Netherlands , Norway , Pakistan , Poland , Russia , Saudi Arabia , South Africa , Spain , Switzerland , Thailand , Turkey , Ukraine , the United Kingdom and the United States , had some satellites in orbit. Japan's space agency (JAXA) and NASA plan to send a wooden satellite prototype called LingoSat into orbit in the summer of 2024. They have been working on this project for few years and sent first wood samples to
3116-521: The North American Aerospace Defense Command , said in October 2015 he believed North Korea had rockets with enough range to hit the continental US and added that "the secretive state had already developed 'miniaturised' nuclear bombs that could be fitted to these rockets". David Albright , former United Nations International Atomic Energy Agency nuclear inspector, on the contrary, thinks Pyongyang can miniaturize
3198-690: The Sohae Satellite Launching Station at Cholsan County in northwestern North Korea. The satellite was to be lifted by a Unha-3 carrier rocket. The satellite launch was timed to coincide with the centenary of Kim Il Sung's birth. The rocket broke up a minute after its launch and the remains fell into the ocean. On 1 December 2012, the Korean Central News Agency said that the Korean Committee for Space Technology announced that it would launch
3280-643: The Tonghae Satellite Launching Ground at Musudan-ri in northeastern North Korea. However, officials in South Korea and the United States reported that the rocket and any payload had fallen into the Pacific Ocean . The Russian Space Control concurred, stating that the satellite "simply is not there". Prior to the launch, concern was raised by other nations, particularly the United States, South Korea and Japan , that
3362-470: The Transit 5-BN-3 . When in a controlled manner satellites reach the end of life they are intentionally deorbited or moved to a graveyard orbit further away from Earth in order to reduce space debris . Physical collection or removal is not economical or even currently possible. Moving satellites out to a graveyard orbit is also unsustainable because they remain there for hundreds of years. It will lead to
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3444-517: 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 Soviet Union announced its intention to launch a satellite by the fall of 1957. Sputnik 2 was launched on 3 November 1957 and carried the first living passenger into orbit, a dog named Laika . The dog was sent without possibility of return. In early 1955, after being pressured by
3526-476: The DPRK announced the test. The Korean Central Television (KCTV) said that "the U.S. has gathered forces hostile to [the] DPRK and raised a slanderous human rights issue to hinder [the] DPRK's improvement. It is [therefore] just to have [an] H-bomb as self-defense against the U.S. having numerous and humongous nuclear weapons. The DPRK's fate must not be protected by any forces but [the] DPRK itself". Ri Chun-hee ,
3608-457: The Earth's vegetation , atmospheric trace gas content, sea state, ocean color, and ice fields. By monitoring vegetation changes over time, droughts can be monitored by comparing the current vegetation state to its long term average. Anthropogenic emissions can be monitored by evaluating data of tropospheric NO 2 and SO 2 . A communications satellite is an artificial satellite that relays and amplifies radio telecommunication signals via
3690-417: The Earth's orbit was the Soviet Union 's Sputnik 1 , on October 4, 1957. As of December 31, 2022, there are 6,718 operational satellites in the Earth's orbit, of which 4,529 belong to the United States (3,996 commercial), 590 belong to China, 174 belong to Russia, and 1,425 belong to other nations. The first published mathematical study of the possibility of an artificial satellite was Newton's cannonball ,
3772-500: The Earth, called remote sensing . Most Earth observation satellites are placed in low Earth orbit for a high data resolution, though some are placed in a geostationary orbit for an uninterrupted coverage. Some satellites are placed in a Sun-synchronous orbit to have consistent lighting and obtain a total view of the Earth. Depending on the satellites' functions, they might have a normal camera , radar , lidar , photometer , or atmospheric instruments. Earth observation satellite's data
3854-553: The Moon and the Sun. Satellites utilize ultra-white reflective coatings to prevent damage from UV radiation. Without orbit and orientation control, satellites in orbit will not be able to communicate with ground stations on the Earth. Chemical thrusters on satellites usually use monopropellant (one-part) or bipropellant (two-parts) that are hypergolic . Hypergolic means able to combust spontaneously when in contact with each other or to
3936-451: The SLV was developed in the 1980s when late leader Kim Il Sung announced the decision to launch a North Korean satellite. The decision to send a North Korean satellite was precipitated by the successful launching of South Korea 's first satellite, Uribyol-1, on 10 August 1992 and its second satellite, Uribyol 2, on 26 September 1993, both by a European Ariane 4 SLV. In a late-1993 meeting of
4018-455: The atmosphere. Given the current surge in satellites in the sky, soon hundreds of satellites may be clearly visible to the human eye at dark sites. It is estimated that the overall levels of diffuse brightness of the night skies has increased by up to 10% above natural levels. This has the potential to confuse organisms, like insects and night-migrating birds, that use celestial patterns for migration and orientation. The impact this might have
4100-603: The atmosphere. For example, SpaceX Starlink satellites, the first large satellite internet constellation to exceed 1000 active satellites on orbit in 2020, are designed to be 100% demisable and burn up completely on their atmospheric reentry at the end of their life, or in the event of an early satellite failure. In different periods, many countries, such as Algeria , Argentina , Australia , Austria , Brazil , Canada , Chile , China , Denmark , Egypt , Finland , France , Germany , India , Iran , Israel , Italy , Japan , Kazakhstan , South Korea , Malaysia , Mexico ,
4182-447: The capability to destroy live satellites. The environmental impact of satellites is not currently well understood as they were previously assumed to be benign due to the rarity of satellite launches. However, the exponential increase and projected growth of satellite launches are bringing the issue into consideration. The main issues are resource use and the release of pollutants into the atmosphere which can happen at different stages of
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#17327806974974264-423: The case of this test, he added that "if it's true, it means they have made something (of a) smaller scale, capable of being put on to a missile" and that North Korea would be aiming to develop a weapon "small enough and light enough to put on to a missile, and the usual parameters are something less than one meter in diameter, and less than a tonne in weight". Admiral Bill Gortney , head of US Northern Command and
4346-551: 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 . In the context of activities planned for the International Geophysical Year (1957–1958),
4428-546: The discovery of the Earth's Van Allen radiation belts . The TIROS-1 spacecraft, launched on April 1, 1960, as part of NASA's Television Infrared Observation Satellite (TIROS) program, sent back the first television footage of weather patterns to be taken from space. 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. While Canada
4510-484: The earth's climate. After deorbiting 70% of satellites end up in the ocean and are rarely recovered. Using wood as an alternative material has been posited in order to reduce pollution and debris from satellites that reenter the atmosphere. Space debris pose dangers to the spacecraft (including satellites) in or crossing geocentric orbits and have the potential to drive a Kessler syndrome which could potentially curtail humanity from conducting space endeavors in
4592-444: The further pollution of space and future issues with space debris. When satellites deorbit much of it is destroyed during re-entry into the atmosphere due to the heat. This introduces more material and pollutants into the atmosphere. There have been concerns expressed about the potential damage to the ozone layer and the possibility of increasing the earth's albedo , reducing warming but also resulting in accidental geoengineering of
4674-551: The future. January 2016 North Korean nuclear test North Korea conducted its fourth nuclear detonation on 6 January 2016 at 10:00:01 UTC+08:30 . At the Punggye-ri Nuclear Test Site , approximately 50 kilometres (30 miles) northwest of Kilju City in Kilju County , an underground nuclear test was carried out. The United States Geological Survey reported a 5.1 magnitude earthquake from
4756-412: The impact of regulated ozone-depleting substances. Whilst emissions of water vapour are largely deemed as inert, H 2 O is the source gas for HO x and can also contribute to ozone loss through the formation of ice particles. Black carbon particles emitted by rockets can absorb solar radiation in the stratosphere and cause warming in the surrounding air which can then impact the circulatory dynamics of
4838-462: The impacts will be more critical than emissions in the troposphere. The stratosphere includes the ozone layer and pollutants emitted from rockets can contribute to ozone depletion in a number of ways. Radicals such as NO x , HO x , and ClO x deplete stratospheric O 3 through intermolecular reactions and can have huge impacts in trace amounts. However, it is currently understood that launch rates would need to increase by ten times to match
4920-527: The launch might be a trial run of technology that could be used in the future to launch an intercontinental ballistic missile . The launch of the rocket was sharply condemned by the United States and the European Union , while the People's Republic of China and Russia urged restraint. Kwangmyŏngsŏng-3 was a polar-orbiting earth observation satellite that North Korea tried to launch 13 April 2012 from
5002-673: The launch; however it urged "the relevant parties" to "refrain from taking actions that may further escalate tensions on the Korean peninsula". The satellite Kwangmyŏngsŏng-1 has since featured prominently in North Korean festivities and celebrations such as the mass games. Commemorative stamps showing the real shape of the satellite still attached to the spin up solid motor orbital insertion third stage and more than two orbits have also been printed on several occasions. Artificial satellite A satellite or artificial satellite
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#17327806974975084-602: The location; the China Earthquake Networks Center reported the magnitude as 4.9. North Korean media announced that the country had successfully tested a hydrogen bomb in "self-defence against US". However, third-party experts as well as officials and agencies in South Korea questioned North Korea's claims and contend that the device was more likely to have been a fission bomb such as a boosted fission weapon . Such weapons use hydrogen fusion to produce smaller, lighter warheads suitable for arming
5166-400: The mid-2000s, satellites have been hacked by militant organizations to broadcast propaganda and to pilfer classified information from military communication networks. For testing purposes, satellites in low earth orbit have been destroyed by ballistic missiles launched from the Earth. Russia , United States , China and India have demonstrated the ability to eliminate satellites. In 2007,
5248-725: The most potent scientific tools of the Twentieth Century." 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. In 1946, American theoretical astrophysicist Lyman Spitzer proposed an orbiting space telescope . In February 1954, Project RAND released "Scientific Uses for
5330-557: The older satellites that reached the end of life , as a part of the regulatory process of obtaining a launch license. The largest artificial satellite ever is the International Space Station . By the early 2000s, and particularly after the advent of CubeSats and increased launches of microsats —frequently launched to the lower altitudes of low Earth orbit (LEO)—satellites began to more frequently be designed to get destroyed, or breakup and burnup entirely in
5412-550: The possible use of communications satellites for mass communications. 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 "A satellite vehicle with appropriate instrumentation can be expected to be one of
5494-412: The quantity of materials that are often left in the ocean. Rocket launches release numerous pollutants into every layer of the atmosphere, especially affecting the atmosphere above the tropopause where the byproducts of combustion can reside for extended periods. These pollutants can include black carbon , CO 2 , nitrogen oxides (NO x ), aluminium and water vapour , but the mix of pollutants
5576-419: The rocket anyway, claiming the satellite was purely intended for peaceful, scientific purposes. Several nations, including the United States , Japan, and South Korea , have criticized the launch, and despite North Korean claims that the rocket was for peaceful purposes, it has been heavily criticized as an attempt to perform an ICBM test under the disguise of a peaceful satellite launch. China also criticized
5658-427: The same point in the sky; therefore the satellite dish antennas of ground stations can be aimed permanently at that spot and do not have to move to track the satellite. Others form satellite constellations in low Earth orbit , where antennas on the ground have to follow the position of the satellites and switch between satellites frequently. When an Earth observation satellite or a communications satellite
5740-409: The satellite; the slip rings can rotate to be perpendicular with the sunlight and generate the most power. All satellites with a solar panel must also have batteries , because sunlight is blocked inside the launch vehicle and at night. The most common types of batteries for satellites are lithium-ion , and in the past nickel–hydrogen . Earth observation satellites are designed to monitor and survey
5822-404: The satellites and receivers on the ground, combined with ever-improving electronics, allows satellite navigation systems to measure location to accuracies on the order of a few meters in real time. Astronomical satellites are satellites used for observation of distant planets, galaxies, and other outer space objects. Tether satellites are satellites that are connected to another satellite by
5904-538: The satellites stay still in the sky (relative to a fixed point on the ground). Some imaging satellites chose a Sun-synchronous orbit because they can scan the entire globe with similar lighting. As the number of satellites and space debris around Earth increases, the threat of collision has become more severe. A small number of satellites orbit other bodies (such as the Moon , Mars , and the Sun ) or many bodies at once (two for
5986-665: The seismic measurements produced" because North Korea does not publicize the depth of its tests, although the material at the Punggye-ri Nuclear Test Site is thought to be hard granite . The tremors were felt in Changbai , Hunchun and Yanji in Jilin province in China. China Central Television released photos of students being evacuated in the area and stated that the ground at a local high school showed cracks. According to China's Foreign Ministry, Beijing had no advance knowledge of
6068-489: The space in 2021 to test the material's resilience to space conditions. Most satellites use chemical or ion propulsion to adjust or maintain their orbit , coupled with reaction wheels to control their three axis of rotation or attitude. Satellites close to Earth are affected the most by variations in the Earth's magnetic , gravitational field and the Sun's radiation pressure ; satellites that are further away are affected more by other bodies' gravitational field by
6150-458: The special conditions of space could be useful for scientific experiments. The book described geostationary satellites (first put forward by Konstantin Tsiolkovsky ) and discussed the communication between them and the ground using radio, but fell short with the idea of using satellites for mass broadcasting and as telecommunications relays. In a 1945 Wireless World article, English science fiction writer Arthur C. Clarke described in detail
6232-480: The status quo in the Korean peninsula and it would be more a change in degree than in kind in military terms". Bruce W. Bennett, a senior defense analyst of the RAND Corporation research organization, is also skeptical, telling BBC News that "the bang they should have gotten would have been 10 times greater… So Kim Jong-un is either lying, saying they did a hydrogen test when they didn't, they just used
6314-459: The stratosphere. Both warming and changes in circulation can then cause depletion of the ozone layer. Several pollutants are released in the upper atmospheric layers during the orbital lifetime of LEO satellites. Orbital decay is caused by atmospheric drag and to keep the satellite in the correct orbit the platform occasionally needs repositioning. To do this nozzle-based systems use a chemical propellant to create thrust. In most cases hydrazine
6396-456: The television news anchor who announced the deaths of Kim Il Sung and Kim Jong Il , emerged from retirement to announce the H-bomb test to both the domestic and international audience. The earthquake caused by the 2016 nuclear test was 5.1 magnitude, similar to the 5.1-magnitude earthquake that accompanied North Korea's previous 2013 nuclear test (which was estimated by South Korea to have
6478-727: The test. Although North Korea declared that the 2016 test was a "successful" demonstration of a hydrogen bomb, international experts and members of the South Korean government expressed skepticism because the explosion was too small; rather, the test may have involved only a boosted fission weapon . Andre Gsponer of the Independent Scientific Research Institute at the University of Oxford said this technology has "a number of significant technical and military advantages, which explain why it
6560-468: The third stage burn. North Korea's leader Kim Jong Il revealed that the country had spent approximately 200–300 million dollars for the satellite project during a summit with then-South Korean president Kim Dae-Jung in 2000. Kwangmyŏngsŏng-2 was a satellite launched by North Korea on 5 April 2009. According to the North Korean government, an Unha-2 rocket carrying the satellite was launched on Sunday 5 April 2009 at 11:20 local time (02:20 UTC) from
6642-426: Was the first academic treatise on the use of rocketry to launch spacecraft. He calculated the orbital speed required for a minimal orbit, and inferred that a multi-stage rocket fueled by liquid propellants could achieve this. Herman Potočnik explored the idea of using orbiting spacecraft for detailed peaceful and military observation of the ground in his 1928 book, The Problem of Space Travel . He described how
6724-483: Was the third country to build a satellite which was launched into space, it was launched aboard an American rocket from an American spaceport. The same goes for Australia, whose launch of the first satellite involved a donated U.S. Redstone rocket and American support staff as well as a joint launch facility with the United Kingdom. The first Italian satellite San Marco 1 was launched on 15 December 1964 on
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