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Spin-stabilisation
Spin stabilization is the method of stabilizing a satellite or launch vehicle by means of spin, i.e. rotation along the longitudinal axis. The concept originates from ballistics, where the spin is commonly obtain by means of rifling. For most satellite applications this approach has been superseded by three-axis stabilization. Despinning can be achieved by various techniques, including yo-yo de-spin. Use On rockets with a solid motor upper stage, spin stabilization is used to keep the motor from drifting off course as they don't have their own thrusters. Usually small rockets are used to spin up the spacecraft and rocket then fire the rocket and send the craft off. Some rockets, like the Jupiter-C, Delta II, Minotaur V and the satellite Aryabhata are spin-stabilised. The Pioneer 4 spacecraft, the second object sent on a lunar flyby in 1959, maintained its attitude using spin-stabilization. The Schiaparelli EDM lander was spun up to 2.5 RPM before being ejected from the ExoMar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Yo-yo De-spin
A yo-yo de-spin mechanism is a device used to reduce the spin of satellites, typically soon after launch. It consists of two lengths of cable with weights on the ends. The cables are wrapped around the final stage and/or satellite, in the manner of a double yo-yo. When the weights are released, the spin of the rocket flings them away from the spin axis. This transfers enough angular momentum to the weights to reduce the spin of the satellite to the desired value. Subsequently, the weights are often released. De-spin is needed since some final stages are spin-stabilized, and require fairly rapid rotation (now typically 30-60 rpm; some early missions, such as Pioneer, rotated at over 600 rpm) to remain stable during firing. (See, for example, the Star 48, a solid fuel rocket motor.) After firing, the satellite cannot be simply released, since such a spin rate is beyond the capability of the satellite's attitude control. Therefore, after rocket firing but before satellite r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spacecraft Attitude Control
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle/satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle attitude requires sensors to measure vehicle orientation, actuators to apply the torques needed to orient the vehicle to a desired attitude, and algorithms to command the actuators based on (1) sensor measurements of the current attitude and (2) specification of a desired attitude. The integrated field that studies the combination of sensors, actuators and algorithms is called guidance, navigation and control (GNC). Overview A spacecraft's attitude must typically be stabilized and controlled for a variety of reasons. It is often needed so that the spacecraft high-gain antenna may be accurately pointed to Earth for communications, so that onboard experiments may accomplish precise pointing for accurate collectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spin-stabilized Satellite
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle/satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle attitude requires sensors to measure vehicle orientation, actuators to apply the torques needed to orient the vehicle to a desired attitude, and algorithms to command the actuators based on (1) sensor measurements of the current attitude and (2) specification of a desired attitude. The integrated field that studies the combination of sensors, actuators and algorithms is called guidance, navigation and control (GNC). Overview A spacecraft's attitude must typically be stabilized and controlled for a variety of reasons. It is often needed so that the spacecraft high-gain antenna may be accurately pointed to Earth for communications, so that onboard experiments may accomplish precise pointing for accurate collection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Star 48
The Star 48 is the largest of a family of solid rocket motors used by many space propulsion and launch vehicle stages. It is used almost exclusively as an upper stage. It was developed primarily by Thiokol Propulsion and is now, after several mergers, manufactured by Northrop Grumman’s Space Systems division. A Star 48B stage is also one of the few man-made items sent on escape trajectories out of the Solar System, although it is derelict since its use. The Star 48B variant was the PAM-D upper stage used on the now retired Delta II rocket. The Star 48 has been used as an upper stage in three- and four-stage launch systems. Overview The "48" designation refers to the approximate diameter of the fuel casing in inches (122 cm); Thiokol had also manufactured other motors such as the Star 37 and Star 30. Internally, Thiokol's designation was TE-M-711 for early versions and TE-M-799 for later ones. Subtypes are given one or more letter suffixes af ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pioneer 4
Pioneer 4 was an American spin-stabilized uncrewed spacecraft launched as part of the Pioneer program on a lunar flyby trajectory and into a heliocentric orbit making it the first probe of the United States to escape from the Earth's gravity. It carried a payload similar to ''Pioneer 3'': a lunar radiation environment experiment using a Geiger–Müller tube detector and a lunar photography experiment. It passed within 58,983 km of the Moon's surface. However, ''Pioneer 4'' did not come close enough to trigger its photoelectric sensor. The spacecraft was still in solar orbit as of 1969. It was the only successful lunar probe launched by the U.S. in 12 attempts between 1958 and 1963; only in 1964 would Ranger 7 surpass its success by accomplishing all of its mission objectives. After the Soviet Luna 1 probe conducted the first successful flyby of the Moon on 3 January 1959, the pressure felt by the US to succeed with a lunar mission was enormous, especially since American ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Three-axis Stabilization
Spacecraft attitude control is the process of controlling the orientation of a spacecraft (vehicle/satellite) with respect to an inertial frame of reference or another entity such as the celestial sphere, certain fields, and nearby objects, etc. Controlling vehicle attitude requires sensors to measure vehicle orientation, actuators to apply the torques needed to orient the vehicle to a desired attitude, and algorithms to command the actuators based on (1) sensor measurements of the current attitude and (2) specification of a desired attitude. The integrated field that studies the combination of sensors, actuators and algorithms is called guidance, navigation and control (GNC). Overview A spacecraft's attitude must typically be stabilized and controlled for a variety of reasons. It is often needed so that the spacecraft high-gain antenna may be accurately pointed to Earth for communications, so that onboard experiments may accomplish precise pointing for accurate collection ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jupiter-C
The Jupiter-C was an American research and development vehicle developed from the Jupiter-A. Jupiter-C was used for three unmanned sub-orbital spaceflights in 1956 and 1957 to test re-entry nosecones that were later to be deployed on the more advanced PGM-19 Jupiter mobile missile. The recovered nosecone was displayed in the Oval Office as part of President Dwight D. Eisenhower's televised speech on November 7, 1957. A member of the Redstone rocket family, Jupiter-C was designed by the U.S. Army Ballistic Missile Agency (ABMA), under the direction of Wernher von Braun. Three Jupiter-C flights were made followed by three satellite launches (Juno I). All were launched from Cape Canaveral, Florida. Description Each vehicle consisted of a modified Redstone ballistic missile with two solid-propellant upper stages. The tanks of the Redstone were lengthened by 8 ft (2.4 m) to provide additional propellant. The instrument compartment was also smaller and lighter than the Reds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Delta II
Delta II was an expendable launch system, originally designed and built by McDonnell Douglas. Delta II was part of the Delta rocket family and entered service in 1989. Delta II vehicles included the Delta 6000, and the two later Delta 7000 variants ("Light" and "Heavy"). The rocket flew its final mission ICESat-2 on 15 September 2018, earning the launch vehicle a streak of 100 successful missions in a row, with the last failure being GPS IIR-1 in 1997. History In the early 1980s, all United States expendable launch vehicles were planned to be phased out in favor of the Space Shuttle, which would be responsible for all government and commercial launches. Production of Delta, Atlas-Centaur, and Titan 34D had ended. The ''Challenger'' disaster of 1986 and the subsequent halt of Shuttle operations changed this policy, and President Ronald Reagan announced in December 1986 that the Space Shuttle would no longer launch commercial payloads, and NASA would seek to purchase launches ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Minotaur V
The Minotaur V is an American expendable launch system derived from the Minotaur IV, itself a derivative of the LGM-118 Peacekeeper ICBM. It was developed by Orbital Sciences Corporation, (now absorbed into Northrop Grumman Innovation Systems) and made its maiden flight on 7 September 2013 carrying the Lunar Atmosphere and Dust Environment Explorer The Lunar Atmosphere and Dust Environment Explorer (LADEE; ) was a NASA lunar exploration and technology demonstration mission. It was launched on a Minotaur V rocket from the Mid-Atlantic Regional Spaceport on September 7, 2013. During its se ... spacecraft for NASA. Design The Minotaur V is a five-stage vehicle, and is designed to place up to of payload into a geosynchronous transfer orbit, or on a trans-lunar injection, trans-lunar trajectory. It consists of a Minotaur IV+, with a Star-37 as a fifth stage. Two variants are available, one with a spin stabilization, spin-stabilized Star-37FM upper stage, and the other with a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aryabhata (satellite)
Aryabhata was India's first satellite,"Aryabhata" in ''Encyclopædia Britannica, The New Encyclopædia Britannica''. Chicago: Encyclopædia Britannica Inc., 15th edn., 1992, Vol. 1, p. 611. named after Aryabhata, the famous Indian astronomer. It was launched on 19 April 1975 from Kapustin Yar, a Soviet rocket launch and development site in Astrakhan Oblast using a Kosmos-3M launch vehicle. It was built by the Indian Space Research Organisation, ISRO, and launched by the Soviet Union as a part of the Soviet Interkosmos programme which provided access to space for friendly states. Launch It was launched by India on 19 April 1975 from Kapustin Yar, a Russian rocket launch and development site in Astrakhan Oblast using a Kosmos-3M launch vehicle. It was built by the Indian Space Research Organisation (ISRO).The launch came from an agreement between India and the Soviet Union directed by Udupi Ramachandra Rao, UR Rao and signed in 1972. It allowed the USSR to use Indian ports for tra ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Launch Vehicle
A launch vehicle or carrier rocket is a rocket designed to carry a payload (spacecraft or satellites) from the Earth's surface to outer space. Most launch vehicles operate from a launch pad, launch pads, supported by a missile launch control center, launch control center and systems such as vehicle assembly and fueling. Launch vehicles are engineered with advanced aerodynamics and technologies, which contribute to large operating costs. An orbital spaceflight, orbital launch vehicle must lift its payload at least to the boundary of space, approximately and accelerate it to a horizontal velocity of at least . Suborbital spaceflight, Suborbital vehicles launch their payloads to lower velocity or are launched at elevation angles greater than horizontal. Practical orbital launch vehicles are multistage rockets which use chemical propellants such as Solid-propellant rocket, solid fuel, liquid hydrogen, kerosene, liquid oxygen, or Hypergolic propellants. Launch vehicles are cla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1959 In Spaceflight
Luna 1 was the first spacecraft to leave the gravitational influence of Earth. Also in 1959, Luna 2 was the first spacecraft to reach the surface of another celestial body, impacting the Moon, and Luna 3 returned the first images of the far side of the Moon The far side of the Moon is the lunar hemisphere that always faces away from Earth, opposite to the Near side of the Moon, near side, because of synchronous rotation in the Moon's orbit. Compared to the near side, the far side's terrain is ru .... Launches January February March April May June July August September October November December Deep Space Rendezvous ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
