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PROBA-3
Proba-3 is a technological demonstration mission by the European Space Agency devoted to high precision formation flying to achieve scientific coronagraphy. It is part of the series of PROBA satellites that are being used to validate new spacecraft technologies and concepts while also carrying scientific instruments. History The mission concept dates back to 2005 when a study was performed in the ESA CDF. After several phase A studies and a change of industrial organisation at the beginning of the phase B, the mission's implementation phase (Phases C/D/E1) eventually began in July 2014. The system CDR has been closed in 2018. Mission concept Proba-3 consists of two independent, three-axis stabilized spacecraft: the Coronagraph Spacecraft (CSC) and the Occulter Spacecraft (OSC). Both spacecraft will fly close to each other on a highly elliptical orbit around the Earth, with an apogee at 60,500 km altitude. Along the apogee arc, when the gravity gradient is significantly sma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PROBA
PROBA is minisatellite technology demonstration mission in ESA's General Study Program with the objective to address issues of on-board operational autonomy of a generic platform. PROBA (Project for On-Board Autonomy), renamed PROBA-1, is a Belgian satellite launched atop an Indian Polar Satellite Launch Vehicle by ISRO on 22 October 2001. The satellite was funded through the ESA's MicroSat program. This small (60×60×80 cm; 95 kg) boxlike system, with solar panel collectors on its surface, has remarkable image-making qualities. It hosts two Earth Observation instruments dubbed CHRIS and HRC. CHRIS is a hyperspectral system (200 narrow bands) that images at 17 m resolution, while HRC is a monochromatic camera that images visible light at 5 m resolution. With an initial lifetime of one to two years, the satellite celebrated its 20th year of operations in 2021. On 9 March 2018, it surpassed ERS-2 as ESA's longest operated Earth observation mission of all time. Series ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PROBA-V
PROBA-V, or PROBA-Vegetation (the ''V'' standing for ''vegetation'' and not the Roman numeral for ''5''), is a satellite in the European Space Agency's PROBA series. It was launched in 2013 with a predicted usable lifetime between 2.5 and 5 years. Satellite ''PROBA-V'' is a small satellite, assuring the succession of the Vegetation instruments on board the French SPOT-4 and SPOT-5 Earth observation missions. PROBA-V was initiated by the Space and Aeronautics department of the BELgian Science Policy Office. It is built by QinetiQ Space N.V. and operated by ESA and uses a PROBA platform. PROBA-V will support applications such as land use, worldwide vegetation classification, crop monitoring, famine prediction, food security, disaster monitoring and biosphere studies. The mission was originally conceived as a "gap filler" between the SPOT-5 end-of-life (foreseen mid-2014) and the launch of the constellation of the Sentinel-3A and -3B satellites. Due to delays of the Sentinel p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SENER
SENER is a private engineering and technology group founded in 1956, and specialises in activities related to Engineering and Construction, and has industrial holdings in companies working in the areas of energy, environment and aeronautics. SENER Ingeniería y Sistemas The Engineering and Construction area, called under the name SENER Ingeniería y Sistemas, has a turnover of more than 653 million euros (2011 figures), about 2,200 employees and branch offices in Algeria, Argentina, Brazil, Japan, Mexico, Poland, Portugal, South Korea, Spain, United Arab Emirates, United States and India. The company develops projects in the sectors of Aerospace, Civil and Architecture, Power and Process and Marine Engineering. Aerospace Engineering During the last 43 years, SENER has supplied equipment, systems integration and engineering services to international markets in the fields of Space, Aeronautics, Vehicles and Defense. In the Space field, the company develops components an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Observatory
A solar observatory is an observatory that specializes in monitoring the Sun. As such, they usually have one or more solar telescopes. The Einstein Tower was a solar observatory in the Albert Einstein Science Park in Potsdam, Germany. Solar observatories study phenomena associated with the Sun. The Sun, being the closest star to earth, allows a unique chance to study stellar physics with high-resolution. It was, until the 1990s, the only star whose surface had been resolved. General topics that interest a solar astronomer are its 11-year periodicity (i.e., the Solar Cycle), sunspots, magnetic field activity (see solar dynamo), solar flares, coronal mass ejections, differential rotation, and plasma physics. Some examples * Huairou Solar Observing Station * Solar observatories in space * National Solar Observatory See also * Coronagraph * Heliometer * Helioscope * List of solar telescopes * Spectroheliograph * Spectrohelioscope * Solar astronomy * Solar tower (astronomy) A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occulter
An occulting disk is a small disk used in a telescope to block the view of a bright object in order to allow observation of a fainter one. The coronagraph, at its simplest, is an occulting disk in the focal plane of a telescope, or in front of the entrance aperture, that blocks out the image of the solar disk, so that the corona can be seen. Starshade is one designed to fly in formation with a space telescope to image exoplanets. See also * New Worlds Mission * Space sunshade A space sunshade or sunshield is a parasol that diverts or otherwise reduces some of the Sun's radiation, preventing it from hitting a spacecraft or planet and thereby reducing its insolation, which results in reduced heating. Light can be di ... * Telescope for Habitable Exoplanets and Interstellar/Intergalactic Astronomy References Optical telescope components Optical devices Star images Stellar astronomy {{astronomy-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Design Review (U
A design review is a milestone within a product development process whereby a design is evaluated against its requirements in order to verify the outcomes of previous activities and identify issues before committing to—and, if need be, to re-prioritise—further work. The ultimate design review, if successful, therefore triggers the product launch or product release. The conduct of design reviews is compulsory as part of design controls, when developing products in certain regulated contexts such as medical devices. By definition, a review must include persons who are external to the design team. Contents of a design review In order to evaluate a design against its requirements, a number of means may be considered, such as: *Physical tests. *Engineering simulations. *Examinations (Walk-through). Timing of design reviews Most formalised systems engineering processes recognise that the cost of correcting a fault increases as it progresses through the development process. Addi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stellar Corona
A corona ( coronas or coronae) is the outermost layer of a star's atmosphere. It consists of plasma. The Sun's corona lies above the chromosphere and extends millions of kilometres into outer space. It is most easily seen during a total solar eclipse, but it is also observable with a coronagraph. Spectroscopic measurements indicate strong ionization in the corona and a plasma temperature in excess of , much hotter than the surface of the Sun, known as the photosphere. The word ''corona'' is , in turn derived . History In 1724, French-Italian astronomer Giacomo F. Maraldi recognized that the aura visible during a solar eclipse belongs to the Sun, not to the Moon. In 1809, Spanish astronomer José Joaquín de Ferrer coined the term 'corona'. Based in his own observations of the 1806 solar eclipse at Kinderhook (New York), de Ferrer also proposed that the corona was part of the Sun and not of the Moon. English astronomer Norman Lockyer identified the first element unknown o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Photosphere
The photosphere is a star's outer shell from which light is radiated. The term itself is derived from Ancient Greek roots, φῶς, φωτός/''phos, photos'' meaning "light" and σφαῖρα/''sphaira'' meaning "sphere", in reference to it being a spherical surface that is perceived to emit light. It extends into a star's surface until the plasma becomes opaque, equivalent to an optical depth of approximately , or equivalently, a depth from which 50% of light will escape without being scattered. A photosphere is the deepest region of a luminous object, usually a star, that is transparent to photons of certain wavelengths. Temperature The surface of a star is defined to have a temperature given by the effective temperature in the Stefan–Boltzmann law. Stars, except neutron stars, have no solid or liquid surface. Therefore, the photosphere is typically used to describe the Sun's or another star's visual surface. Composition of the Sun The Sun is composed primarily of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metrology
Metrology is the scientific study of measurement. It establishes a common understanding of units, crucial in linking human activities. Modern metrology has its roots in the French Revolution's political motivation to standardise units in France when a length standard taken from a natural source was proposed. This led to the creation of the decimal-based metric system in 1795, establishing a set of standards for other types of measurements. Several other countries adopted the metric system between 1795 and 1875; to ensure conformity between the countries, the Bureau International des Poids et Mesures (BIPM) was established by the Metre Convention. This has evolved into the International System of Units (SI) as a result of a resolution at the 11th General Conference on Weights and Measures (CGPM) in 1960. Metrology is divided into three basic overlapping activities: * The definition of units of measurement * The realisation of these units of measurement in practice * Traceabi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Rendezvous
A space rendezvous () is a set of orbital maneuvers during which two spacecraft, one of which is often a space station, arrive at the same orbit and approach to a very close distance (e.g. within visual contact). Rendezvous requires a precise match of the orbital velocities and position vectors of the two spacecraft, allowing them to remain at a constant distance through orbital station-keeping. Rendezvous may or may not be followed by docking or berthing, procedures which bring the spacecraft into physical contact and create a link between them. The same rendezvous technique can be used for spacecraft "landing" on natural objects with a weak gravitational field, e.g. landing on one of the Martian moons would require the same matching of orbital velocities, followed by a "descent" that shares some similarities with docking. History In its first human spaceflight program Vostok, the Soviet Union launched pairs of spacecraft from the same launch pad, one or two days apart ( V ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acta Astronautica
''Acta Astronautica'' is a monthly peer-reviewed scientific journal covering all fields of physical, engineering, life, and social sciences related to the peaceful scientific exploration of space. The journal is widely known as one of the top aerospace engineering journals. The journal was established in 1955 under the name ''Astronautica Acta'', obtaining its current title in 1974, with volume-numbering simultaneously restarting at 1. The journal is published by Elsevier, sponsored by the International Academy of Astronautics. Abstracting and indexing The journal is abstracted and indexed in: According to the ''Journal Citation Reports'', the journal has a 2020 impact factor The impact factor (IF) or journal impact factor (JIF) of an academic journal is a scientometric index calculated by Clarivate that reflects the yearly mean number of citations of articles published in the last two years in a given journal, as i ... of 2.413. References External links * Space scienc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronagraph
A coronagraph is a telescopic attachment designed to block out the direct light from a star so that nearby objects – which otherwise would be hidden in the star's bright glare – can be resolved. Most coronagraphs are intended to view the corona of the Sun, but a new class of conceptually similar instruments (called ''stellar coronagraphs'' to distinguish them from ''solar coronagraphs'') are being used to find extrasolar planets and circumstellar disks around nearby stars as well as host galaxies in quasars and other similar objects with active galactic nuclei (AGN). Invention The coronagraph was introduced in 1931 by the French astronomer Bernard Lyot; since then, coronagraphs have been used at many solar observatories. Coronagraphs operating within Earth's atmosphere suffer from scattered light in the sky itself, due primarily to Rayleigh scattering of sunlight in the upper atmosphere. At view angles close to the Sun, the sky is much brighter than the background cor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
