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B-DECIGO
The DECi-hertz Interferometer Gravitational wave Observatory (or DECIGO) is a proposed Japanese, space-based, gravitational wave observatory. The laser interferometric gravitational wave detector is so named because it is to be most sensitive in the frequency band between 0.1 and 10 Hz, filling in the gap between the sensitive bands of LIGO and LISA. If funding can be found, its designers hope to launch it in 2027. The design is similar to LISA, with three zero-drag satellites in a triangular arrangement, but using a smaller separation of only 1000 km whose relative displacements are measured by a Fabry–Pérot Michelson interferometer. The precursor mission B-DECIGO with 100 km long arms is planned to be launched in the late 2020s, target is an Earth orbit with an average altitude of 2000 km. See also * Laser Interferometer Space Antenna (LISA) * List of proposed space observatories This list contains proposals for space telescopes, space-based (situated in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
B-DECIGO
The DECi-hertz Interferometer Gravitational wave Observatory (or DECIGO) is a proposed Japanese, space-based, gravitational wave observatory. The laser interferometric gravitational wave detector is so named because it is to be most sensitive in the frequency band between 0.1 and 10 Hz, filling in the gap between the sensitive bands of LIGO and LISA. If funding can be found, its designers hope to launch it in 2027. The design is similar to LISA, with three zero-drag satellites in a triangular arrangement, but using a smaller separation of only 1000 km whose relative displacements are measured by a Fabry–Pérot Michelson interferometer. The precursor mission B-DECIGO with 100 km long arms is planned to be launched in the late 2020s, target is an Earth orbit with an average altitude of 2000 km. See also * Laser Interferometer Space Antenna (LISA) * List of proposed space observatories This list contains proposals for space telescopes, space-based (situated in s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Geocentric Orbit
A geocentric orbit or Earth orbit involves any object orbiting Earth, such as the Moon or artificial satellites. In 1997, NASA estimated there were approximately 2,465 artificial satellite payloads orbiting Earth and 6,216 pieces of space debris as tracked by the Goddard Space Flight Center. More than 16,291 objects previously launched have undergone orbital decay and entered Earth's atmosphere. A spacecraft enters orbit when its centripetal acceleration due to gravity is less than or equal to the centrifugal acceleration due to the horizontal component of its velocity. For a low Earth orbit, this velocity is about ; by contrast, the fastest crewed airplane speed ever achieved (excluding speeds achieved by deorbiting spacecraft) was in 1967 by the North American X-15. The energy required to reach Earth orbital velocity at an altitude of is about 36 MJ/kg, which is six times the energy needed merely to climb to the corresponding altitude. Spacecraft with a perigee belo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fabry–Pérot Interferometer
In optics, a Fabry–Pérot interferometer (FPI) or etalon is an optical cavity made from two parallel reflecting surfaces (i.e.: thin mirrors). Optical waves can pass through the optical cavity only when they are in resonance with it. It is named after Charles Fabry and Alfred Perot, who developed the instrument in 1899. ''Etalon'' is from the French ''étalon'', meaning "measuring gauge" or "standard". Etalons are widely used in telecommunications, lasers and spectroscopy to control and measure the wavelengths of light. Recent advances in fabrication technique allow the creation of very precise tunable Fabry–Pérot interferometers. The device is technically an interferometer when the distance between the two surfaces (and with it the resonance length) can be changed, and an etalon when the distance is fixed (however, the two terms are often used interchangeably). Basic description The heart of the Fabry–Pérot interferometer is a pair of partially reflective glass ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proposed Spacecraft
Proposal(s) or The Proposal may refer to: * Proposal (business) * Research proposal * Proposal (marriage) * Proposition, a proposal in logic and philosophy Arts, entertainment, and media * ''The Proposal'' (album) Films * ''The Proposal'' (1957 film), an Australian television play based on Chekhov's 1890 play * ''The Proposal'' (2001 film), starring Nick Moran, Jennifer Esposito, and Stephen Lang * ''The Proposal'' (2009 film), starring Sandra Bullock and Ryan Reynolds * ''The Proposal'' (2022 film), starring Joe Joseph and Amara Raja * " La propuesta" ("The Proposal"), a short story in the 2014 Argentina anthology film ''Wild Tales'' Literature * ''Proposals (play)'', a 1997 play by Neil Simon * ''The Proposal'' (novel), 1999 and 35th book in the ''Animorphs'' series by K.A. Applegate * ''The Proposal'', alternative title of Chekhov's 1890 play ''A Marriage Proposal'' Television * ''The Proposal'' (American TV series), a 2018 reality dating series * The Proposal (Aust ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Astronomy In Japan
Astronomy () is a natural science that studies celestial objects and phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies, and comets. Relevant phenomena include supernova explosions, gamma ray bursts, quasars, blazars, pulsars, and cosmic microwave background radiation. More generally, astronomy studies everything that originates beyond Earth's atmosphere. Cosmology is a branch of astronomy that studies the universe as a whole. Astronomy is one of the oldest natural sciences. The early civilizations in recorded history made methodical observations of the night sky. These include the Babylonians, Greeks, Indians, Egyptians, Chinese, Maya, and many ancient indigenous peoples of the Americas. In the past, astronomy included disciplines as diverse as astrometry, celestial navigation, observational astronomy, and the making of calendars. Nowadays, professional ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Interferometric Gravitational-wave Instruments
Interferometry is a technique which uses the ''interference (wave propagation), interference'' of Superposition principle, superimposed waves to extract information. Interferometry typically uses electromagnetic waves and is an important investigative technique in the fields of astronomy, Optical fiber, fiber optics, engineering metrology, optical metrology, oceanography, seismology, spectroscopy (and its applications to chemistry), quantum mechanics, Nuclear physics, nuclear and particle physics, plasma physics, remote sensing, interactome, biomolecular interactions, surface profiling, microfluidics, mechanical stress/strain measurement, velocimetry, optometry, and making holograms. Interferometers are devices that extract information from interference. They are widely used in science and industry for the measurement of microscopic displacements, refractive index changes and surface irregularities. In the case with most interferometers, light from a single source is split into ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Telescopes
A space telescope or space observatory is a telescope in outer space used to observe astronomical objects. Suggested by Lyman Spitzer in 1946, the first operational telescopes were the American Orbiting Astronomical Observatory, OAO-2 launched in 1968, and the Soviet Orion 1 ultraviolet telescope aboard space station Salyut 1 in 1971. Space telescopes avoid the filtering and distortion ( scintillation) of electromagnetic radiation which they observe, and avoid light pollution which ground-based observatories encounter. They are divided into two types: Satellites which map the entire sky (astronomical survey), and satellites which focus on selected astronomical objects or parts of the sky and beyond. Space telescopes are distinct from Earth imaging satellites, which point toward Earth for satellite imaging, applied for weather analysis, espionage, and other types of information gathering. History Wilhelm Beer and Johann Heinrich Mädler in 1837 discussed the advantages of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Proposed Space Observatories
This list contains proposals for space telescopes, space-based (situated in space) astronomical observatories. It is a list of past and present space observatory plans, concepts, and proposals. For observatories in orbit, see list of space telescopes. Unlike that list, this one includes concepts and proposals that are unlikely ever to be launched, as they may have been cancelled or were only proposals. Space observatories under development Merged, cancelled, or superseded space observatories Additional examples and non-space telescopes For launch in the 2030s, NASA is evaluating four possible designs: the Origins Space Telescope, Lynx X-ray Surveyor, Habitable Exoplanet Imaging Mission (HabEx), and Large UV Optical Infrared Surveyor ( LUVOIR). Balloon-borne telescopes have been in use since the 1950s. A 20–30 meter balloon telescope has been suggested. The balloon would be transparent on one side, and have a circular reflecting mirror on the other side. There are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zero-drag Satellite
Zero-drag satellites or drag-free satellites are satellites where the payload follows a geodesic In geometry, a geodesic () is a curve representing in some sense the shortest path ( arc) between two points in a surface, or more generally in a Riemannian manifold. The term also has meaning in any differentiable manifold with a connection. ... path through space only affected by gravity and not by non-gravitational forces such as Drag (physics), drag of the residual atmosphere, light pressure and solar wind. A zero-drag satellite has two parts, an outer shell and an inner mass called the ''proof mass''. The proof mass floats freely inside the outer shell, while the distance between the outer shell and the proof mass is constantly measured. When a change in the distance between the outer shell and the proof mass is detected, it means that the outer shell has been influenced by non-gravitational forces and moved relative to the proof mass. Thrusters on the outer shell will the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Low Earth Orbit
A low Earth orbit (LEO) is an orbit around Earth with a period of 128 minutes or less (making at least 11.25 orbits per day) and an eccentricity less than 0.25. Most of the artificial objects in outer space are in LEO, with an altitude never more than about one-third of the radius of Earth. The term ''LEO region'' is also used for the area of space below an altitude of (about one-third of Earth's radius). Objects in orbits that pass through this zone, even if they have an apogee further out or are sub-orbital, are carefully tracked since they present a collision risk to the many LEO satellites. All crewed space stations to date have been within LEO. From 1968 to 1972, the Apollo program's lunar missions sent humans beyond LEO. Since the end of the Apollo program, no human spaceflights have been beyond LEO. Defining characteristics A wide variety of sources define LEO in terms of altitude. The altitude of an object in an elliptic orbit can vary significantly along the orbit. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Laser Interferometer Space Antenna
The Laser Interferometer Space Antenna (LISA) is a proposed space probe to detect and accurately measure gravitational waves—tiny ripples in the fabric of spacetime—from astronomical sources. LISA would be the first dedicated space-based gravitational wave detector. It aims to measure gravitational waves directly by using laser interferometry. The LISA concept has a constellation of three spacecraft arranged in an equilateral triangle with sides 2.5 million kilometres long, flying along an Earth-like heliocentric orbit. The distance between the satellites is precisely monitored to detect a passing gravitational wave. The LISA project started out as a joint effort between NASA and the European Space Agency (ESA). However, in 2011, NASA announced that it would be unable to continue its LISA partnership with the European Space Agency due to funding limitations. The project is a recognized CERN experiment (RE8). A scaled down design initially known as the New Gravitational-wave ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LIGO
The Laser Interferometer Gravitational-Wave Observatory (LIGO) is a large-scale physics experiment and observatory designed to detect cosmic gravitational waves and to develop gravitational-wave observations as an astronomical tool. Two large observatories were built in the United States with the aim of detecting gravitational waves by laser interferometry. These observatories use mirrors spaced four kilometers apart which are capable of detecting a change of less than one ten-thousandth the charge diameter of a proton. (that is, to Proxima Centauri at ). The initial LIGO observatories were funded by the United States National Science Foundation (NSF) and were conceived, built and are operated by Caltech and MIT. They collected data from 2002 to 2010 but no gravitational waves were detected. The Advanced LIGO Project to enhance the original LIGO detectors began in 2008 and continues to be supported by the NSF, with important contributions from the United Kingdom's Science ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
