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Small Satellites
A small satellite, miniaturized satellite, or smallsat is a satellite of low mass and size, usually under . While all such satellites can be referred to as "small", different classifications are used to categorize them based on mass. Satellites can be built small to reduce the large economic cost of launch vehicles and the costs associated with construction. Miniature satellites, especially in large numbers, may be more useful than fewer, larger ones for some purposes – for example, gathering of scientific data and radio relay. Technical challenges in the construction of small satellites may include the lack of sufficient power storage or of room for a propulsion system. Rationales One rationale for miniaturizing satellites is to reduce the cost; heavier satellites require larger rockets with greater thrust that also have greater cost to finance. In contrast, smaller and lighter satellites require smaller and cheaper launch vehicles and can sometimes be launched in mult ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medium Earth Orbit
A medium Earth orbit (MEO) is an geocentric orbit, Earth-centered orbit with an altitude above a low Earth orbit (LEO) and below a high Earth orbit (HEO) – between above sea level.''Catalog of Earth Satellite Orbits'' NASA Earth Observatory. 4 September 2009. Accessed 2 May 2021. The boundary between MEO and LEO is an arbitrary altitude chosen by accepted convention, whereas the boundary between MEO and HEO is the particular altitude of a geosynchronous orbit, in which a satellite takes 24 hours to circle the Earth, the same period as the Earth’s own rotation. All satellites in MEO have an orbital period of less than 24 hours, with the minimum period (for a circular orbit at the lowest MEO altitude) about 2 hours. Satellites in MEO or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Picard (satellite)
PICARD is a satellite dedicated to the simultaneous measurement of the absolute total and spectral solar irradiance, the diameter and solar shape, and to the Sun's interior probing by the helioseismology method. These measurements obtained throughout the mission allow study of their variations as a function of solar activity. It launched, along with the Prisma spacecraft, on 15 June 2010 on a Dnepr launcher from Dombarovskiy Cosmodrome, near Yasny, Russia. The mission, originally planned for two years, ended on 4 April 2014. Objectives The objectives of the PICARD mission are to improve our knowledge of: * the functioning of our star through new observations, * the influence of the solar activity on the climate of the Earth. History The PICARD mission was named after the French astronomer of the 17th century Jean Picard (1620–1682) who achieved the first accurate measurements of the solar diameter. These measurements are especially important as they were made during a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Parasol (satellite)
PARASOL (Polarization & Anisotropy of Reflectances for Atmospheric Sciences coupled with Observations from a Lidar) was a French-built Earth observing research satellite. It carried an instrument called POLDER, which studied the radiative and microphysical properties of clouds and aerosols. PARASOL was launched from the French spaceport in Kourou, French Guiana on December 18, 2004, by an Ariane 5 G+. It flew in formation in the " A Train" constellation with several other satellites ( Aqua, CALIPSO, CloudSat and Aura). These satellites had, for the first time ever, combined a full suite of instruments for observing clouds and aerosols, from passive radiometers to active lidar and radar Radar is a system that uses radio waves to determine the distance ('' ranging''), direction ( azimuth and elevation angles), and radial velocity of objects relative to the site. It is a radiodetermination method used to detect and track ... sounders. On 2 December 2009, PARASO ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
