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Titan IV
Titan IV was a family of heavy-lift space launch vehicles developed by Martin Marietta and operated by the United States Air Force from 1989 to 2005. Launches were conducted from Cape Canaveral Air Force Station, Florida and Vandenberg Air Force Base, California. The Titan IV was the last of the Titan family of rockets, originally developed by the Glenn L. Martin Company in 1958. It was retired in 2005 due to their high cost of operation and concerns over its toxic hypergolic propellants, and replaced with the Atlas V and Delta IV launch vehicles under the EELV program. The final launch (B-30) from Cape Canaveral occurred on 29 April 2005, and the final launch from Vandenberg AFB occurred on 19 October 2005. Lockheed Martin Space Systems built the Titan IVs near Denver, Colorado, under contract to the US government. Two Titan IV vehicles are currently on display at the National Museum of the United States Air Force in Dayton, Ohio and the Evergreen Aviation and Space Museu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vandenberg AFB Space Launch Complex 4
Space Launch Complex 4 (SLC-4) is a launch and landing site at Vandenberg Space Force Base, California, U.S. It has two pads, both of which are used by SpaceX for Falcon 9, one for launch operations, and other as Landing Zone 4 (LZ-4) for SpaceX landings. The complex was previously used by Atlas and Titan rockets between 1963 and 2005. It consisted of two launch pads, SLC-4W and SLC-4E, which were formerly designated PALC-2-3 and PALC-2-4 respectively. Both pads were built for use by Atlas-Agena rockets, but were later rebuilt to handle Titan rockets. The designation SLC-4 was applied at the time of the conversion to launch Titan launch vehicles. Both pads at Space Launch Complex 4 are currently leased by SpaceX. SLC-4E is leased as a launch site for the Falcon 9 rocket, which first flew from Vandenberg on 29 September 2013, following a 24-month refurbishment program which had started in early 2011. SpaceX began a five-year lease of Launch Complex 4 West in February 2015 in o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aerozine 50
__NOTOC__ Aerozine 50 is a 50:50 mix by weight of hydrazine and unsymmetrical dimethylhydrazine (UDMH), originally developed in the late 1950s by Aerojet General Corporation as a storable, high-energy, hypergolic fuel for the Titan II ICBM rocket engines. Aerozine continues in wide use as a rocket fuel, typically with dinitrogen tetroxide as the oxidizer, with which it is hypergolic. Aerozine 50 is more stable than hydrazine alone, and has a higher density and boiling point than UDMH alone. Pure hydrazine has a higher performance than Aerozine 50, but an unacceptable freezing point. By mixing pure hydrazine with UDMH, hydrazine's inconveniently high freezing point of 2 °C is lowered through freezing-point depression. In addition, UDMH is a more stable molecule; this reduces the chances of straight hydrazine decomposing unexpectedly, increasing safety and allowing the blend to be used as a coolant in regeneratively cooled engines. This type of fuel is mainly used for inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinitrogen Tetroxide
Dinitrogen tetroxide, commonly referred to as nitrogen tetroxide (NTO), and occasionally (usually among ex-USSR/Russia rocket engineers) as amyl, is the chemical compound N2O4. It is a useful reagent in chemical synthesis. It forms an equilibrium mixture with nitrogen dioxide. Its molar mass is 92.011 g/mol. Dinitrogen tetroxide is a powerful oxidizer that is hypergolic (spontaneously reacts) upon contact with various forms of hydrazine, which has made the pair a common bipropellant for rockets. Structure and properties Dinitrogen tetroxide could be regarded as two nitro groups (-NO2) bonded together. It forms an equilibrium mixture with nitrogen dioxide. The molecule is planar with an N-N bond distance of 1.78Å and N-O distances of 1.19Å. The N-N distance corresponds to a weak bond, since it is significantly longer than the average N-N single bond length of 1.45Å. This exceptionally weak σ bond (amounting to overlapping of the ''sp''2 hybrid orbitals of the two NO2 units) ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
LR87
The LR87 was an American liquid-propellant rocket engine used on the first stages of Titan intercontinental ballistic missiles and launch vehicles. Composed of twin motors with separate combustion chambers and turbopump machinery, it is considered a single unit. The LR87 first flew in 1959. The LR87 was developed in the late 1950s by Aerojet. It was the first production rocket engine capable (in its various models) of burning the three most common liquid rocket propellant combinations: liquid oxygen/RP-1, nitrogen tetroxide (NTO)/Aerozine 50 (a 50:50 mixture by mass of hydrazine and UDMH), and liquid oxygen/liquid hydrogen. The engine operated on an open gas-generator cycle and utilized a regeneratively cooled combustion chamber. For each thrust chamber assembly, a single high-speed turbine drove the lower-speed centrifugal fuel and oxidizer pumps through gearing, a configuration designed for high turbopump efficiency. This lowered fuel use in the gas generator and improved ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydroxyl-terminated Polybutadiene
Hydroxyl-terminated polybutadiene (HTPB) is an oligomer of butadiene terminated at each end with a hydroxyl functional group. It reacts with isocyanates to form polyurethane polymers. HTPB is a translucent liquid with a color similar to wax paper and a viscosity similar to corn syrup. The properties vary because HTPB is a mixture rather than a pure compound, and it is manufactured to meet customers' specific requirements. A typical HTPB is R-45HTLO. This product consists of oligomeric units typically containing 40–50 butadiene molecules bonded together, with each end of the chain terminated with a hydroxyl Hgroup: R-45HTLO has a functionality of 2.4-2.6, which means that there is (approximately) one additional hydroxyl group located along the chain for every two oligomeric units. This provides side-to-side linkage for a stronger cured product. HTPB is usually cured by an addition reaction with di- or poly-isocyanate compounds. Uses Materials Production Polyurethanes prepare ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hercules Inc
Hercules, Inc. was a chemical and munitions manufacturing company based in Wilmington, Delaware, United States, incorporated in 1912 as the Hercules Powder Company following the breakup of the DuPont explosives monopoly by the U.S. Circuit Court in 1911. Hercules Powder Company became Hercules, Inc. in 1966, operating under this name until 2008, when it was merged into Ashland Inc. An earlier Hercules Powder Company was formed in 1882 by DuPont and Laflin & Rand Powder Company. This company was dissolved on June 30, 1904. Hercules was one of the major producers of smokeless powder for warfare in the United States during the 20th century. At the time of its spin-off, the DuPont Corp. retained the processes and patents for the production of "single-base" nitrocellulose gunpowders, whereas Hercules was given the patents and processes for the production of "double-base" gunpowders that combined nitrocellulose and nitroglycerine. History A special formulation of dynamite wa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polybutadiene Acrylonitrile
Polybutadiene acrylonitrile (PBAN) copolymer, also noted as polybutadiene—acrylic acid—acrylonitrile terpolymer is a copolymer compound used most frequently as a rocket propellant fuel mixed with ammonium perchlorate oxidizer. It was the binder formulation widely used on the 1960s–1970s big booster rocket, boosters (e.g., Titan III and Space Shuttle Solid Rocket Booster, Space Shuttle SRBs). Polybutadiene acrylonitrile is also sometimes used by amateurs due to simplicity, very low cost, and lower toxicity than the more common hydroxyl-terminated polybutadiene (HTPB). HTPB uses isocyanates for curing, which have a relatively quick curing time; however, they are also generally toxic. PBAN based propellants also have a slightly higher performance than HTPB based propellants. PBAN is normally cured with the addition of an epoxy resin, taking several days at elevated temperatures to cure. Usages PBAN was to be used in the Constellation program, later canceled, as this co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pounds-force
The pound of force or pound-force (symbol: lbf, sometimes lbf,) is a unit of force used in some systems of measurement, including English Engineering units and the foot–pound–second system. Pound-force should not be confused with pound-mass (lb), often simply called ''pound'', which is a unit of mass, nor should these be confused with foot-pound (ft⋅lbf), a unit of energy, or pound-foot (lbf⋅ft), a unit of torque. Definitions The pound-force is equal to the gravitational force exerted on a mass of one avoirdupois pound on the surface of Earth. Since the 18th century, the unit has been used in low-precision measurements, for which small changes in Earth's gravity (which varies from equator to pole by up to half a percent) can safely be neglected. The 20th century, however, brought the need for a more precise definition, requiring a standardized value for acceleration due to gravity. Product of avoirdupois pound and standard gravity The pound-force is the product ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Newton (force)
The newton (symbol: N) is the unit of force in the International System of Units (SI). It is defined as 1 kg⋅m/s, the force which gives a mass of 1 kilogram an acceleration of 1 metre per second per second. It is named after Isaac Newton in recognition of his work on classical mechanics, specifically Newton's second law of motion. Definition A newton is defined as 1 kg⋅m/s (it is a derived unit which is defined in terms of the SI base units). One newton is therefore the force needed to accelerate one kilogram of mass at the rate of one metre per second squared in the direction of the applied force. The units "metre per second squared" can be understood as measuring a rate of change in velocity per unit of time, i.e. an increase in velocity by 1 metre per second every second. In 1946, Conférence Générale des Poids et Mesures (CGPM) Resolution 2 standardized the unit of force in the MKS system of units to be the amount needed to accelerate 1 kilogram of mass at the rate of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UA120
UA120 was a family of American solid rocket boosters, manufactured by the Chemical Systems Division of United Aircraft (later United Technologies Corporation). Several variants existed, with a varying number of segments. Design All versions of UA120 shared a common design, with the only significant differentiating factor being the length of the motor. It was a segmented design, with between five and seven motor segments possible. A solid propellant, polybutadiene acrylonitrile (PBAN), was used as fuel. The stage had an external diameter of 120 inches. Attitude control in flight was provided by means of a liquid injection thrust vector control (LITVC) system, with an external nacelle containing nitrogen tetroxide attached to the side of each booster. Solid fueled separation rockets, used to jettison the spent boosters, were affixed at the top and bottom of the stage. Thrust-termination capability, necessary for manned rockets such as the Space Shuttle or Manned Orbiting Laboratory, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Milstar
Milstar (Military Strategic and Tactical Relay) is a constellation of military communications satellites in geosynchronous orbit, which are operated by the United States Space Force, and provide secure and jam-resistant worldwide communications to meet the requirements of the Armed Forces of the United States. Six spacecraft were launched between 1994 and 2003, of which five are currently operational; the third launch failed, both damaging the satellite and leaving it in an unusable orbit. History Milstar Block I spacecraft, or Milstar Developmental Flight Satellite (DFS)-1 and -2, were designed with a Low Data Rate (LDR) payload in the wing of the satellite that broadcast in the Super High Frequency (SHF) and Extremely High Frequency (EHF) ranges, and also a classified communication payload in the wing. The DFS-1 satellite was launched on 7 February 1994 aboard the first Titan IV(401)A rocket, but with the classified wing payload deactivated. It was followed by the DFS-2 s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
