Taiyuan Satellite Launch Center
The Taiyuan Satellite Launch Center known as Base 25, is a People's Republic of China space and defence launch facility. It is situated in Kelan County, Shanxi Province and is the second of four launch sites having been founded in March 1966 and coming into full operation in 1968. Taiyuan sits at an altitude of 1500 meters and its dry weather makes it an ideal launch site. Confusingly, U. S. intelligence designates TSLC the'Wuzhai Missile and Space Test Centre", despite the fact that it is outside the borders of Wuzhai County. The site is used to launch meteorological satellites, earth resource satellites and scientific satellites on Long March launch vehicles into sun-synchronous orbits. TSLC is a major launch site for intercontinental ballistic missiles and overland Submarine-Launched Ballistic Missile tests; the site has Control Center. It is served by two feeder railways. 7 Launch Site: CZ-1D, CZ-2C/SD, CZ-4A, CZ-4B and CZ-4C vehicles. 9 Launch Site: CZ-2C, CZ-4B and CZ-4C. First use on 25 October 2008.
16 Launch Site: CZ-6 Taiyuan Satellite Launch Center will launch a satellite coded as the 03 Group of the Shijian-6 serial research satellites sometime on 2008-10-24. The rocket carrier will be a Long March 4B, said the official, noting both the satellite and the rocket were in good condition and all the preparations for the launch had been completed. Space program of China Jiuquan Satellite Launch Center Xichang Satellite Launch Center Wenchang Satellite Launch Center
The Dong Feng 31 is a long-range, road-mobile, three stage, solid-fuel rocket intercontinental ballistic missile in the Dongfeng missile series developed by the People's Republic of China. It is designed to carry a single 1-megaton thermonuclear weapon, it is a land-based variant of the submarine-launched JL-2. It is operated by the Second Artillery Corps which, in 2009, was estimated to have under 15 DF-31 missiles and under 15 DF-31A missiles in inventory. US Air Force National Air and Space Intelligence Center estimates that as of June 2017, five to ten Mod 1 and over fifteen Mod 2 launchers were operationally deployed; the PRC began developing the DF-31 as a second-generation ICBM successor of the DF-4 in January 1985. ARMT was appointed as the main contractor while the research arm of the Second Artillery Corps provided contributing support; the land-based variant of the JL-2 was called the DF-23 but was changed on to the DF-31 because of a change in operational requirements. In 1999, the missile was first displayed publicly at the National Day Parade.
On August 2, 1999, the Chinese state news media reported the successful test of the DF-31. The third test flight of the missile occurred on November 4, 2000. Operational deployment of the missiles began in 2006. In 2009, US Air Force Intelligence reported; the DF-31 is a three stage solid-fuel rocket equipped with an inertial navigation system. The missile is mounted on a transporter erector launcher, it is capable of reaching targets throughout Europe and parts of Canada and the northwestern United States. The PRC has developed an improved variant of the DF-31 called the DF-31A; this upgraded missile has a reported range of 11,200 km, will allow targeting of most of the continental United States and was designed with MIRV capability to hold 3 to 5 warheads, each capable of a 20–150 kt yield, but is thought to be armed with only one warhead with penetration and decoy aids to complicate missile defense efforts. The missile was shown to the public during the parade in Beijing celebrating 70 years since the end of World War II on September 3, 2015.
It can carry maneuverable reentry vehicles. The PRC has developed an improved variant of the DF-31A called the DF-31AG or DF-31B with an off-road 8 axle TEL and MIRVs. China has tested it from a mobile launcher; the missile's TEL features an extra pair of elevators near the aft of the missile unlike the TELs of the DF-31 or DF-31A, suggesting a heavier missile second and third stage than earlier variants. On the military parade marking the 90th Anniversary of the founding of the PLA, DF-31AG ICBM was demonstrated for the first time. Giacometti, Nicolas. "China's Nuclear Modernization and the End of Nuclear Opacity". Thediplomat.com. Retrieved 12 April 2014. CSIS Missile Threat - Dong Feng-31 Encyclopedia Astronautica
Mu (rocket family)
The Mu known as M, was a series of Japanese solid-fuelled carrier rockets, which were launched from Uchinoura between 1966 and 2006. Developed by Japan's Institute of Space and Astronautical Science, Mu rockets were operated by Japan Aerospace Exploration Agency following its merger with ISAS; the first Mu rocket, the Mu-1 made a single, sub-orbital, test flight, on 31 October 1966. Subsequently, a series of rockets were produced, designated Mu-3 and Mu-4. In 1969 a suborbital test launch of the Mu-3D was conducted; the first orbital launch attempt for the Mu family, using a Mu-4S, was conducted on 25 September 1970, however the fourth stage did not ignite, the rocket failed to reach orbit. On 16 February 1971, Tansei 1 was launched by another Mu-4S rocket. Two further Mu-4S launches took place during 1971 and 1972; the Mu-4S was replaced by the Mu-3C, was launched four times between 1974 and 1979, with three successes and one failure, the Mu-3H, launched three times in 1977 and 1978. The Mu-3S was used between 1984, making four launches.
The final member of the Mu-3 family was the Mu-3SII, launched eight times between 1985 and 1995. The Mu-3 was replaced in service by the M-V; the M-V, or Mu-5, was introduced in 1997 and retired in 2006. Seven launches, six of which were successful, were conducted; the M-V flew in a three-stage configuration, however a four-stage configuration, designated M-V KM was used 3 times, with the MUSES-B satellite in 1997, Nozomi spacecraft in 1998, the Hayabusa spacecraft in 2003. The three-stage configuration had a maximum payload of 1,800 kg for an orbit with altitude of 200 km and inclination of 30°, 1,300 kg to a polar orbit, with an altitude of 200 km; the M-V KM could launch 1,800 kg to an orbit with 400 km altitude. The three stage M-V had a total launch mass of 137,500 kg, whilst the total mass of a four-stage M-V KM was 139,000 kg. All launches are from the Mu Launch Pad at the Uchinoura Space Center. ^Note Two sub-orbital launches of the Mu family were performed prior to its first orbital flight: the 1.5 stage Mu-1 flew on October 31, 1966 at 05:04 UTC and the 3.5 stage Mu-3D flew on August 17, 1969 at 06:00 UTC.
Epsilon J-I Comparison of orbital launchers families Comparison of orbital launch systems Mu series in Encyclopedia Astronautica ISAS Satellite Launch Vehicles
A launch vehicle or carrier rocket is a rocket used to carry a payload from Earth's surface through outer space, either to another surface point, or into space. A launch system includes the launch vehicle, launch pad, vehicle assembly and fuelling systems, range safety, other related infrastructure. Suborbital launch vehicles include ballistic missiles, sounding rockets, various crewed systems designed for space tourism or high-speed transport. Orbital or escape launch vehicles must be much more powerful and incorporate two to four rocket stages to provide sufficient delta-v performance. Various rocket fuels are used, including solid rocket boosters and cryogenic fuels fed to rocket engines. Most launch vehicles are expendable i.e. used only once and destroyed or abandoned during the flight. Attempts to reduce per-launch costs have led to reusable launch systems, in which part of the launch vehicle is recovered and reused for another flight. Multiple classes of launch vehicle exist for use with differing launch sites, payload mass, target orbits, price points, etc.
Numerous countries have sought to develop indigenous launch vehicles for use in national space programs. Expendable launch vehicles are designed for one-time use, they separate from their payload and disintegrate during atmospheric reentry. In contrast, reusable launch vehicles are designed to be launched again; the Space Shuttle was a part of a launch vehicle with components used for multiple orbital spaceflights. SpaceX has developed a reusable rocket launching system to bring back a part—the first stage—of their Falcon 9 and launch it again, With B1046 having flown a total of three flights making it the most flown orbital class booster, Falcon Heavy launch vehicles. A reusable VTVL design is planned for all parts of the ITS launch vehicle; the low-altitude flight test program of an experimental technology-demonstrator launch vehicle began in 2012, with more extensive high-altitude over-water flight testing planned to begin in mid-2013, continue on each subsequent Falcon 9 flight. Non-rocket spacelaunch alternatives are progressing.
In June 2017, Stratolaunch Systems began ground testing the carrier aircraft component of its air launch to orbit system. The Stratolaunch is the world's largest aircraft, weighing 500,000 pounds and composed of twin fuselages with an overall wingspan of 385 feet; the Spanish company Zero 2 Infinity is developing another launch system concept, the Bloostar, a balloon-borne launcher based on rockoon technology. Launch vehicles are classified by the amount of mass they can carry into a particular orbit. For example, a Proton rocket can lift 22,000 kilograms into low Earth orbit. Launch vehicles are characterized by their number of stages. Rockets with as many as five stages have been launched, there have been designs for several single-stage-to-orbit vehicles. Additionally, launch vehicles are often supplied with boosters supplying high early thrust burning with other engines. Boosters allow the remaining engines to be smaller, reducing the burnout mass of stages to allow larger payloads. Other reported characteristics of launch vehicles are the launching nation or space agency and the company or consortium manufacturing and launching the vehicle.
For example, the European Space Agency is responsible for the Ariane V, the United Launch Alliance manufactures and launches the Delta IV and Atlas V rockets. Many launch vehicles are considered part of a historical line of vehicles of the same or similar name. Land: spaceport and fixed missile silo for converted ICBMs Sea: fixed platform, mobile platform, submarine for converted SLBMs Air: aircraft, balloon, JP Aerospace Orbital Ascender, proposal for permanent Buoyant space port. There are many ways to classify the sizes of launch vehicles; the US civilian space agency, NASA, uses a classification scheme, articulated by the Augustine Commission created to review plans for replacing the Space Shuttle: A sounding rocket, used to study the atmosphere or perform brief experiments, is only capable of sub-orbital spaceflight and cannot reach orbit. A small-lift launch vehicle is capable of lifting up to 2,000 kg of payload into low Earth orbit. A medium-lift launch vehicle is capable of lifting 2,000 to 20,000 kg of payload into LEO.
A heavy-lift launch vehicle is capable of lifting 20,000 to 50,000 kg of payload into LEO. A super-heavy lift vehicle is capable of lifting more than 50,000 kg of payload into LEO; the leading European launch service provider, Arianespace uses the "heavy-lift" designation for its >20,000 kg -to-LEO Ariane 5 launch vehicle and "medium-lift" for its array of launch vehicles that lift 2,000 to 20,000 kg to LEO, including the Starsem/Arianespace Soyuz ST and pre-1999 versions of the Ariane 5. It refers to its 1,500 kg to LEO Vega launch vehicle as "light lift". Suborbital launch vehicles are not capable of taking their payloads to the minimum horizontal speed necessary to achieve low Earth orbit with a perigee less than the Earth's mean radius, which speed is about 7,800 m/s. Sounding rockets have long been used for brief, inexpensive unmanne
Long March 2D
The Long March 2D known as the Chang Zheng 2D, CZ-2D and LM-2D, is a Chinese orbital carrier rocket. It is a 2-stage carrier rocket used for launching LEO and SSO satellites, it is launched from areas 2B and 4 at the Jiuquan Satellite Launch Center. The Long March 2D made its maiden flight on 9 August 1992, it is most used to launch FSW-2 and -3 reconnaissance satellites. Unlike all other members of the Long March 2 rocket family, Long March 2D is a two-stage version of Long March 4 launch vehicle; the Long March 2D made its maiden flight on 9 August 1992
Reaction control system
A reaction control system is a spacecraft system that uses thrusters to provide attitude control, sometimes translation. Use of diverted engine thrust to provide stable attitude control of a short-or-vertical takeoff and landing aircraft below conventional winged flight speeds, such as with the Harrier "jump jet", may be referred to as a reaction control system. An RCS is capable of providing small amounts of thrust in any desired direction or combination of directions. An RCS is capable of providing torque to allow control of rotation. Reaction control systems use combinations of large and small thrusters, to allow different levels of response. Spacecraft reaction control systems are used for: attitude control during re-entry; because spacecraft only contain a finite amount of fuel and there is little chance to refill them, alternative reaction control systems have been developed so that fuel can be conserved. For stationkeeping, some spacecraft use high-specific impulse engines such as arcjets, ion thrusters, or Hall effect thrusters.
To control orientation, a few spacecraft, including the ISS, use momentum wheels which spin to control rotational rates on the vehicle. The Mercury space capsule and Gemini re-entry module both used groupings of nozzles to provide attitude control; the thrusters were located off their center of gravity, thus providing a torque to rotate the capsule. The Gemini capsule was capable of adjusting its re-entry course by rolling, which directed its off-center lifting force; the Mercury thrusters used a hydrogen peroxide monopropellant which turned to steam when forced through a tungsten screen, the Gemini thrusters used hypergolic mono-methyl hydrazine fuel oxidized with nitrogen tetroxide. The Gemini spacecraft was equipped with a hypergolic Orbit Attitude and Maneuvering System, which made it the first manned spacecraft with translation as well as rotation capability. In-orbit attitude control was achieved by firing pairs of eight 25-pound-force thrusters located around the circumference of its adapter module at the extreme aft end.
Lateral translation control was provided by four 100-pound-force thrusters around the circumference at the forward end of the adaptor module. Two forward-pointing 85-pound-force thrusters at the same location, provided aft translation, two 100-pound-force thrusters located in the aft end of the adapter module provided forward thrust, which could be used to change the craft's orbit; the Apollo Command Module had a set of twelve hypergolic thrusters for attitude control, directional re-entry control similar to Gemini. The Apollo Service Module and Lunar Module each had a set of sixteen R-4D hypergolic thrusters, grouped into external clusters of four, to provide both translation and attitude control; the clusters were located near the craft's centers of gravity, were fired in pairs in opposite directions for attitude control. A pair of translation thrusters are located at the rear of the Soyuz spacecraft; these act in pairs to prevent the spacecraft from rotating. The thrusters for the lateral directions are mounted close to the center of mass of the spacecraft, in pairs as well.
The suborbital X-15 and a companion training aero-spacecraft, the NF-104 AST, both intended to travel to an altitude that rendered their aerodynamic control surfaces unusable, established a convention for locations for thrusters on winged vehicles not intended to dock in space. Those for pitch and yaw are located in the nose, forward of the cockpit, replace a standard radar system; those for roll are located at the wingtips. The X-20, which would have gone into orbit, continued this pattern. Unlike these, the Space Shuttle Orbiter had many more thrusters, as it was required to carry out docking maneuvers in orbit. Shuttle thrusters were grouped in the nose of the vehicle and on each of the two aft Orbital Maneuvering System pods. No nozzles interrupted the heat shield on the underside of the craft; the downward-facing negative pitch thrusters were located in the OMS pods mounted in the tail/afterbody. The International Space Station uses electrically powered reaction control gyroscopes for primary attitude control, with RCS thruster systems as backup and augmentation systems.
Space Shuttle RCS Jet Aerospace: Mono-fuel RCS thruster
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. Technologies and procedures allowing the controlled atmospheric entry and landing of spacecraft are collectively termed as EDL. Atmospheric drag and aerodynamic heating can cause atmospheric breakup capable of disintegrating smaller objects; these forces may cause objects with lower compressive strength to explode. Crewed space vehicles must be slowed to subsonic speeds before parachutes or air brakes may be deployed; such vehicles have kinetic energies between 50 and 1,800 megajoules, atmospheric dissipation is the only way of expending the kinetic energy. The amount of rocket fuel required to slow the vehicle would be nearly equal to the amount used to accelerate it and it is thus impractical to use retro rockets for the entire Earth reentry procedure.
While the high temperature generated at the surface of the heat shield is due to adiabatic compression, the vehicle's kinetic energy is lost to gas friction after the vehicle has passed by. Other smaller energy losses include black-body radiation directly from the hot gases and chemical reactions between ionized gases. Ballistic warheads and expendable vehicles do not require slowing at reentry, in fact, are made streamlined so as to maintain their speed. Furthermore, slow-speed returns to Earth from near-space such as parachute jumps from balloons do not require heat shielding because the gravitational acceleration of an object starting at relative rest from within the atmosphere itself cannot create enough velocity to cause significant atmospheric heating. For Earth, atmospheric entry occurs at the Kármán line at an altitude of 100 km above the surface, while at Venus atmospheric entry occurs at 250 km and at Mars atmospheric entry at about 80 km. Uncontrolled, objects reach high velocities while accelerating through space toward the Earth under the influence of Earth's gravity, are slowed by friction upon encountering Earth's atmosphere.
Meteors are often travelling quite fast relative to the Earth because their own orbital path is different from that of the Earth before they encounter Earth's gravity well. Most controlled objects enter at hypersonic speeds due to their suborbital, orbital, or unbounded trajectories. Various advanced technologies have been developed to enable atmospheric reentry and flight at extreme velocities. An alternative low velocity method of controlled atmospheric entry is buoyancy, suitable for planetary entry where thick atmospheres, strong gravity, or both factors complicate high-velocity hyperbolic entry, such as the atmospheres of Venus and the gas giants; the concept of the ablative heat shield was described as early as 1920 by Robert Goddard: "In the case of meteors, which enter the atmosphere with speeds as high as 30 miles per second, the interior of the meteors remains cold, the erosion is due, to a large extent, to chipping or cracking of the heated surface. For this reason, if the outer surface of the apparatus were to consist of layers of a infusible hard substance with layers of a poor heat conductor between, the surface would not be eroded to any considerable extent as the velocity of the apparatus would not be nearly so great as that of the average meteor."Practical development of reentry systems began as the range and reentry velocity of ballistic missiles increased.
For early short-range missiles, like the V-2, stabilization and aerodynamic stress were important issues, but heating was not a serious problem. Medium-range missiles like the Soviet R-5, with a 1,200-kilometer range, required ceramic composite heat shielding on separable reentry vehicles; the first ICBMs, with ranges of 8,000 to 12,000 kilometers, were only possible with the development of modern ablative heat shields and blunt-shaped vehicles. In the United States, this technology was pioneered by H. Julian Allen and A. J. Eggers Jr. of the National Advisory Committee for Aeronautics at Ames Research Center. In 1951, they made the counterintuitive discovery that a blunt shape made the most effective heat shield. From simple engineering principles and Eggers showed that the heat load experienced by an entry vehicle was inversely proportional to the drag coefficient. If the reentry vehicle is made blunt, air cannot "get out of the way" enough, acts as an air cushion to push the shock wave and heated shock layer forward.
Since most of the hot gases are no longer in direct contact with the vehicle, the heat energy would stay in the shocked gas and move around the vehicle to dissipate into the atmosphere. The Allen and Eggers discovery, though treated as a military secret, was published in 1958. Over the decades since the 1950s, a rich technical jargon has grown around the engineering of vehicles designed to enter planetary atmospheres, it is recommended that the reader review the jargon glossary before continuing with this article on atmospheric reentry. When atmospheric entry is pa