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Sfera (satellite)
Sfera (TEKh-44) is a small passive satellite deployed during a spacewalk from the ISS in August 2012. Description Also called the Vektor-T calibration sphere, the Sfera satellite is used to determine the density of the upper atmosphere by measuring how much drag occurs when the satellite passes through it. TEKh-44 is a shiny sphere 53 cm (20.8 inches) across weighing 14 kg (~31 pounds). Re-entry It re-entered the atmosphere in late November 2012. See also *List of passive satellites List of passive satellites is a listing of inert or mostly inert satellites, mainly of the Earth. This includes various reflector type satellites typically used for geodesy and atmospheric measurements. Passive satellites *Calsphere **Calsphere ... References External linksSfera deployed Passive satellites Spacecraft which reentered in 2012 Spheres Atmospheric sounding satellites {{Russia-spacecraft-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Satellite
A satellite or artificial satellite is an object intentionally placed into orbit in outer space. 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 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 is small CubeSats. Similar satellites can work together as a group, forming constellations. Because of the high launch cost to space, 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 a bandwidth of tens of megahertz. Satellites are placed from the surface to orbit by launch vehicles, high enough to avoid orbital decay by the atmosphere. Satellites can then change or maintain the orbit by pr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacewalk
Extravehicular activity (EVA) is any activity done by an astronaut in outer space outside a spacecraft. In the absence of a breathable Earthlike atmosphere, the astronaut is completely reliant on a space suit for environmental support. EVA includes ''spacewalks'' and lunar or planetary surface exploration (commonly known from 1969 to 1972 as ''moonwalks''). In a stand-up EVA (SEVA), an astronaut stands through an open hatch but does not fully leave the spacecraft. EVA has been conducted by the Soviet Union/Russia, the United States, Canada, the European Space Agency and China. On March 18, 1965, Alexei Leonov became the first human to perform a spacewalk, exiting the Voskhod 2 capsule for 12 minutes and 9 seconds. On July 20, 1969, Neil Armstrong became the first human to perform a moonwalk, outside his lunar lander on Apollo 11 for 2 hours and 31 minutes. On the last three Moon missions, astronauts also performed deep-space EVAs on the return to Earth, to retrieve film canist ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Upper Atmosphere
Upper atmosphere is a collective term that refers to various layers of the atmosphere of the Earth above the troposphere and corresponding regions of the atmospheres of other planets, and includes: * The mesosphere, which on Earth lies between the altitudes of about , sometimes considered part of the "middle atmosphere" rather than the upper atmosphere * The thermosphere, which on Earth lies between the altitudes of about * The exosphere, which on Earth lies between the altitudes of about and * The ionosphere, an ionized portion of the upper atmosphere which includes the upper mesosphere, thermosphere, and lower exosphere and on Earth lies between the altitudes of See also * Geospace *Magnetosphere In astronomy and planetary science, a magnetosphere is a region of space surrounding an astronomical object in which charged particles are affected by that object's magnetic field. It is created by a celestial body with an active interior dynamo ... References {{Reflist Atmosp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Atmospheric Entry
Atmospheric entry is the movement of an object from outer space into and through the gases of an atmosphere of a planet, dwarf planet, or natural satellite. There are two main types of atmospheric entry: ''uncontrolled entry'', such as the entry of astronomical objects, space debris, or bolides; and ''controlled entry'' (or ''reentry'') of a spacecraft capable of being navigated or following a predetermined course. Technologies and procedures allowing the controlled atmospheric ''entry, descent, and landing'' of spacecraft are collectively termed as ''EDL''. Objects entering an atmosphere experience atmospheric drag, which puts mechanical stress on the object, and aerodynamic heating—caused mostly by compression of the air in front of the object, but also by drag. These forces can cause loss of mass ( ablation) or even complete disintegration of smaller objects, and objects with lower compressive strength can explode. Crewed space vehicles must be slowed to subsonic s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of Passive Satellites
List of passive satellites is a listing of inert or mostly inert satellites, mainly of the Earth. This includes various reflector type satellites typically used for geodesy and atmospheric measurements. Passive satellites *Calsphere **Calsphere 1A **Calsphere 2 **Calsphere 3 **Calsphere 4 **Calsphere 4A **Calsphere 5 *Dragsphere 1 *Dragsphere 2 *Enoch * Explorer 9 *GFZ-1 * Humanity Star * LCS-1 *PAGEOS *PAMS-STU, see STS-77 *POPACS *Reflector * PasComSat *Rigid Sphere 1 (AVL-802H) *Rigid Sphere 2 * Sfera Dedicated laser ranging satellites Mostly passive satellites *Starshine 3, see Athena I *Echo project **Echo 1 (Echo 1A) **Echo 2 * Elon Musk's Tesla Roadster *Hayabusa2 **Deployable camera 3 (DCAM3) **Small Carry-On Impactor (SCI) **Target Marker B **Target Marker A **Target Marker E (Explorer) **Target Marker C (Sputnik/Спутник) * Tianwen-1 ** Tianwen-1 Deployable Camera 1 ** Tianwen-1 Remote Camera ** Tianwen-1 Deployable Camera 2 See also * List of laser ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Passive Satellites
Passive may refer to: * Passive voice, a grammatical voice common in many languages, see also Pseudopassive * Passive language, a language from which an interpreter works * Passivity (behavior), the condition of submitting to the influence of one's superior * Passive-aggressive behavior, resistance to following through with expectations in interpersonal or occupational situations * Passive income, income resulting from cash flow received on a regular basis * Passive immunity, the transfer of active humoral immunity * Passive experience, observation lacking recipricol interaction; and wrought with delusion of control. Science and technology * Passivation (chemistry), process of making a material "passive" in relation to another material prior to using the materials together * Passivity (engineering) a property of engineering systems, particularly in analog electronics and control systems * Passive solar building design, which uses (or avoids) sunlight as an energy source without ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacecraft Which Reentered In 2012
A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, planetary exploration, and transportation of humans and cargo. All spacecraft except single-stage-to-orbit vehicles cannot get into space on their own, and require a launch vehicle (carrier rocket). On a sub-orbital spaceflight, a space vehicle enters space and then returns to the surface without having gained sufficient energy or velocity to make a full Earth orbit. For orbital spaceflights, spacecraft enter closed orbits around the Earth or around other celestial bodies. Spacecraft used for human spaceflight carry people on board as crew or passengers from start or on orbit (space stations) only, whereas those used for robotic space missions operate either autonomously or telerobotically. Robotic spacecraft used to support scientific res ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spheres
The Synchronized Position Hold Engage and Reorient Experimental Satellite (SPHERES) are a series of miniaturized satellites developed by MIT's Space Systems Laboratory for NASA and US Military, to be used as a low-risk, extensible test bed for the development of metrology, formation flight, rendezvous, docking and autonomy algorithms that are critical for future space missions that use distributed spacecraft architecture, such as Terrestrial Planet Finder and Orbital Express. Each SPHERES satellite is an 18-sided polyhedron, with a mass of about 4.1 kg and a diameter of about 21 cm. They can be used in the International Space Station as well as in ground-based laboratories, but not in the vacuum of space. The battery-powered, self-contained units can operate semi-autonomously, using CO2-based cold-gas thrusters for movement and a series of ultrasonic beacons for orientation. The satellites can communicate with each other and with a control station wirelessly. The built ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
