|
Laser Communication In Space
Laser communication in space is the use of free-space optical communication in outer space. Communication may be fully in space (an inter-satellite laser link) or in a ground-to-satellite or satellite-to-ground application. The main advantage of using laser communications over Radio, radio waves is increased Bandwidth (computing), bandwidth, enabling the transfer of more data in less time. In outer space, the communication range of free-space optical communication is currently of the order of hundreds of thousands of kilometers. Laser-based optical communication has been demonstrated between the Earth and Moon and it has the potential to bridge interplanetary distances of millions of kilometers, using optical telescopes as beam expanders. Demonstrations and tests Before 1990 On 20 January 1968, the television camera of the Surveyor 7 lunar lander successfully detected two Ion laser, argon lasers from Kitt Peak National Observatory in Arizona and Table Mountain Observatory ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Two Solar-powered Satellites Communicating Optically In Space Via Lasers
2 (two) is a number, numeral (linguistics), numeral and numerical digit, digit. It is the natural number following 1 and preceding 3. It is the smallest and the only even prime number. Because it forms the basis of a Dualistic cosmology, duality, it has Religion, religious and Spirituality, spiritual significance in many Culture, cultures. Mathematics The number 2 is the second natural number after 1. Each natural number, including 2, is constructed by succession, that is, by adding 1 to the previous natural number. 2 is the smallest and the only even prime number, and the first Ramanujan prime. It is also the first superior highly composite number, and the first colossally abundant number. An integer is determined to be Parity (mathematics), even if it is Division (mathematics), divisible by two. When written in base 10, all Multiple (mathematics), multiples of 2 will end in 0, 2, 4, 6, or 8; more generally, in any even base, even numbers will end with an even digit. A dig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tokyo
Tokyo, officially the Tokyo Metropolis, is the capital of Japan, capital and List of cities in Japan, most populous city in Japan. With a population of over 14 million in the city proper in 2023, it is List of largest cities, one of the most populous urban areas in the world. The Greater Tokyo Area, which includes Tokyo and parts of six neighboring Prefectures of Japan, prefectures, is the most populous metropolitan area in the world, with 41 million residents . Lying at the head of Tokyo Bay, Tokyo is part of the Kantō region, on the central coast of Honshu, Japan's largest island. It is Japan's economic center and the seat of the Government of Japan, Japanese government and the Emperor of Japan. The Tokyo Metropolitan Government administers Tokyo's central Special wards of Tokyo, 23 special wards, which formerly made up Tokyo City; various commuter towns and suburbs in Western Tokyo, its western area; and two outlying island chains, the Tokyo Islands. Although most of the w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gbit/s
In telecommunications, data transfer rate is the average number of bits ( bitrate), characters or symbols ( baudrate), or data blocks per unit time passing through a communication link in a data-transmission system. Common data rate units are multiples of bits per second (bit/s) and bytes per second (B/s). For example, the data rates of modern residential high-speed Internet connections are commonly expressed in megabits per second (Mbit/s). Standards for unit symbols and prefixes Unit symbol The ISQ symbols for the bit and byte are ''bit'' and ''B'', respectively. In the context of data-rate units, one byte consists of 8 bits, and is synonymous with the unit octet. The abbreviation bps is often used to mean bit/s, so that when a ''1 Mbps'' connection is advertised, it usually means that the maximum achievable bandwidth is 1 Mbit/s (one million bits per second), which is 0.125 MB/s ( megabyte per second), or about 0.1192 MiB/s ( mebibyte per second). ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
OICETS
The Optical Inter-orbit Communications Engineering Test Satellite (OICETS), also called ''Kirari'', was an experimental satellite launched by JAXA to demonstrate interorbital communication between satellites through optical (laser) means. OICETS was originally slated for a launch on the second J-I launcher. Due to problems with that launcher, the launch had to be put on hold. Using the H-IIA was out of question: it would have been overkill to use the H-IIA to send a satellite into low Earth orbit, and there was no budget for another H-IIA launch. Finally, in order to be able to perform the tests during the lifetime of the European Artemis satellite (since 2014, sold to Avanti Communications to exploit its Ka, S, and L-band payloads), OICETS was successfully launched on a Russian-Ukrainian Dnepr rocket. The satellite was decommissioned and its mission terminated on 24 September 2009 at 05:48 UTC. Achievements *On 9 December 2005, JAXA succeeded in establishing optical li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neodymium Laser
Nd:YAG (neodymium-doped yttrium aluminum garnet; Nd:Y3Al5O12) is a crystal that is used as a lasing medium for solid-state lasers. The dopant, neodymium in the +3 oxidation state, Nd(III), typically replaces a small fraction (1%) of the yttrium ions in the host crystal structure of the yttrium aluminum garnet (YAG), since the two ions are of similar size.Koechner §2.3, pp. 48–53. It is the neodymium ion which provides the lasing activity in the crystal, in the same fashion as red chromium ion in ruby lasers. Laser operation of Nd:YAG was first demonstrated by et al. at Bell Laboratories in 1964. Geusic and LeGrand Van Uitert received the Optical Society of America's R. W. Wood Prize in 1993 “for the discovery of the Nd:YAG laser and the demonstration of its usefulness as a practical solid state laser source”. Technology Nd: YAG lasers are optically pumped using a flashtube or laser diodes. These are one of the most common types of laser, and are used for many differen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MESSENGER
Messenger, Messengers, The Messenger or The Messengers may refer to: People * Courier, a person or company that delivers messages, packages, or mail * Messenger (surname) * Bicycle messenger, a bicyclist who transports packages through cities * Messenger-at-arms, an officer of the Scottish Court of Session * Messenger of the Court, a court officer responsible for carrying communications and executing other orders * Prophets and messengers in Islam * Muhammad and other prophets in Islam, who were known as Messengers of Allah (God) Science and technology Biology and chemistry * Chemical messenger, such as a hormone or neurotransmitter, a molecule used for cellular signalling * Messenger RNA (mRNA), RNA that carries information from DNA to the ribosome sites of protein synthesis in a cell Electronics and computing *Instant messenger, a tool for online text communication **Facebook Messenger, an instant messaging service by Meta (Facebook) **Microsoft Messenger service, an instant me ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Altimeter
A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word ''laser'' originated as an acronym for light amplification by stimulated emission of radiation. The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories, based on theoretical work by Charles H. Townes and Arthur Leonard Schawlow and the optical amplifier patented by Gordon Gould. A laser differs from other sources of light in that it emits light that is ''coherent''. Spatial coherence allows a laser to be focused to a tight spot, enabling uses such as optical communication, laser cutting, and lithography. It also allows a laser beam to stay narrow over great distances (collimation), used in laser pointers, lidar, and free-space optical communication. Lasers can also have high temporal coherence, which permits them to emit light with a very narrow frequency spectrum. Temporal coherence can also ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mercury (planet)
Mercury is the first planet from the Sun. It is a rocky planet with a trace atmosphere. While it is the List of Solar System objects by size, smallest and least massive planet of the Solar System, its surface gravity is slightly higher than that of Mars. The surface of Mercury is similar to Earth's Moon, heavily Impact crater, cratered, with expansive rupes system, generated from thrust faults, and bright ray systems, formed by ejecta. Its largest crater, Caloris Planitia, has a diameter of , which is about one-third the diameter of the planet (). Being the most inferior planet, inferior orbiting planet it appears in Earth's sky, always close to the Sun, either as a "morning star" or an "evening star". It stays most of the time the closest to all other planets and is the planet with the highest delta-v needed to travel to from all other planets of the Solar System. Mercury's sidereal year (88.0 Earth days) and sidereal day (58.65 Earth days) are in a 3:2 ratio. This relation ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Optical Inter-orbit Communications Engineering Test Satellite
The Optical Inter-orbit Communications Engineering Test Satellite (OICETS), also called ''Kirari'', was an experimental satellite launched by JAXA to demonstrate interorbital communication between satellites through optical (laser) means. OICETS was originally slated for a launch on the second J-I launcher. Due to problems with that launcher, the launch had to be put on hold. Using the H-IIA was out of question: it would have been overkill to use the H-IIA to send a satellite into low Earth orbit, and there was no budget for another H-IIA launch. Finally, in order to be able to perform the tests during the lifetime of the European Artemis satellite (since 2014, sold to Avanti Communications to exploit its Ka, S, and L-band payloads), OICETS was successfully launched on a Russian-Ukrainian Dnepr rocket. The satellite was decommissioned and its mission terminated on 24 September 2009 at 05:48 UTC. Achievements *On 9 December 2005, JAXA succeeded in establishing optical link ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SPOT (satellite)
SPOT (, lit. "Satellite for observation of Earth") is a commercial high-resolution optical Earth observation satellite system operating from space. It is run by Spot Image, based in Toulouse, France. It was initiated by the CNES (''Centre national d'études spatiales'' – the French space agency) in the 1970s and was developed in association with the SSTC (Belgian scientific, technical and cultural services) and the Swedish National Space Board (SNSB). It has been designed to improve the knowledge and management of the Earth by exploring the Earth's resources, detecting and forecasting phenomena involving climatology and oceanography, and monitoring human activities and natural phenomena. The SPOT system includes a series of satellites and ground control resources for satellite control and programming, image production, and distribution. Earlier satellites were launched using the European Space Agency's Ariane 2, 3, and 4 rockets, while SPOT 6 and SPOT 7 were launched by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Earth Observation Satellite
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. The first occurrence of satellite remote sensing can be dated to the launch of the first artificial satellite, Sputnik 1, by the Soviet Union on October 4, 1957. Sputnik 1 sent back radio signals, which scientists used to study the ionosphere. The United States Army Ballistic Missile Agency launched the first American satellite, Explorer 1, for NASA's Jet Propulsion Laboratory on January 31, 1958. The information sent back from its radiation detector led to the discovery of the Earth's Van ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
CNES
CNES () is the French national space agency. Headquartered in central Paris, the agency is overseen by the ministries of the Armed Forces, Economy and Finance and Higher Education, Research and Innovation. It operates from the Toulouse Space Centre and the Guiana Space Centre. The president of CNES is Philippe Baptiste. CNES is a member of Institute of Space, its Applications and Technologies. It is Europe's largest national organization of its type. History CNES was established under President Charles de Gaulle in 1961. It is the world's third oldest space agency, after the Soviet space program (Russia), and NASA (United States). CNES was responsible for the training of French astronauts, until the last active CNES astronauts transferred to the European Space Agency in 2001. , CNES is working with Germany and a few other governments to start a modest research effort with the hope to propose a LOX/methane reusable launch vehicle by mid-2015. If built, flight testing w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
