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A detonator, sometimes called a blasting cap in the US, is a small sensitive device used to provoke a larger, more powerful but relatively insensitive secondary explosive of an explosive device used in commercial mining, excavation, demolition, etc.
Pyrotechnics is the science and craft of creating such things as fireworks, safety matches, oxygen candles, explosive bolts and other fasteners, parts of automotive airbags, as well as gas-pressure blasting in mining, quarrying, and demolition. This trade relies upon self-contained and self-sustained exothermic chemical reactions to make heat, light, gas, smoke and/or sound. The name comes from the Greek words pyr ("fire") and tekhnikos.
Mercury-Redstone 4 was the second United States human spaceflight, on July 21, 1961. The suborbital Project Mercury flight was launched with a Mercury-Redstone Launch Vehicle, MRLV-8. The spacecraft, Mercury capsule #11, was nicknamed Liberty Bell 7. It was piloted by astronaut Virgil "Gus" Grissom.
The exploding-bridgewire detonator is a type of detonator used to initiate the detonation reaction in explosive materials, similar to a blasting cap because it is fired using an electric current. EBWs use a different physical mechanism than blasting caps, using more electricity delivered much more rapidly. Exploding with more precise timing after the electric current is applied, by the process of exploding wire method. This has led to their common use in nuclear weapons.
The Apollo spacecraft was composed of three parts designed to accomplish the American Apollo program's goal of landing astronauts on the Moon by the end of the 1960s and returning them safely to Earth. The expendable (single-use) spacecraft consisted of a combined command and service module (CSM) and an Apollo Lunar Module (LM). Two additional components complemented the spacecraft stack for space vehicle assembly: a spacecraft–LM adapter (SLA) designed to shield the LM from the aerodynamic stress of launch and to connect the CSM to the Saturn launch vehicle and a launch escape system (LES) to carry the crew in the command module safely away from the launch vehicle in the event of a launch emergency.
The Space Shuttle Solid Rocket Booster (SRB) was the first solid-propellant rocket to be used for primary propulsion on a vehicle used for human spaceflight. A pair of these provided 85% of the Space Shuttle's thrust at liftoff and for the first two minutes of ascent. After burnout, they were jettisoned and parachuted into the Atlantic Ocean where they were recovered, examined, refurbished, and reused.
In an explosive, pyrotechnic device, or military munition, a fuse is the part of the device that initiates function. In common usage, the word fuse is used indiscriminately. However, when being specific, the term fuse describes a simple pyrotechnic initiating device, like the cord on a firecracker whereas the term fuze is used when referring to a more sophisticated ignition device incorporating mechanical and/or electronic components, such as a proximity fuze for an M107 artillery shell, magnetic or acoustic fuze on a sea mine, spring-loaded grenade fuze, pencil detonator, or anti-handling device.
The Apollo command and service module (CSM) was one of two principal components of the United States Apollo spacecraft, used for the Apollo program, which landed astronauts on the Moon between 1969 and 1972. The CSM functioned as a mother ship, which carried a crew of three astronauts and the second Apollo spacecraft, the Apollo Lunar Module, to lunar orbit, and brought the astronauts back to Earth. It consisted of two parts: the conical command module, a cabin that housed the crew and carried equipment needed for atmospheric reentry and splashdown; and the cylindrical service module which provided propulsion, electrical power and storage for various consumables required during a mission. An umbilical connection transferred power and consumables between the two modules. Just before reentry of the command module on the return home, the umbilical connection was severed and the service module was cast off and allowed to burn up in the atmosphere.
Little Joe II was an American rocket used from 1963 to 1966 for five uncrewed tests of the Apollo spacecraft launch escape system (LES), and to verify the performance of the command module parachute recovery system in abort mode. It was named after a similar rocket designed for the same function in Project Mercury. Launched from White Sands Missile Range in New Mexico, it was the smallest of four launch rockets used in the Apollo program.
A squib is a miniature explosive device used in a wide range of industries, from special effects to military applications. It resembles a tiny stick of dynamite, both in appearance and construction, but has considerably less explosive power. A squib consists of two electrical leads separated by a plug of insulating material; a small bridge wire or electrical resistance heater; and a bead of heat-sensitive chemical composition, in which the bridge wire is embedded. They can be used to generate mechanical force to shatter or propel various materials; and for pyrotechnic effects for film and live theatrics.
A slapper detonator, also called exploding foil initiator (EFI), is a detonator developed by Lawrence Livermore National Laboratory, US Patent No. 4,788,913. It is an improvement over the earlier exploding-bridgewire detonator. Instead of directly coupling the shock wave from the exploding wire, the expanding plasma from an explosion of a metal foil drives another thin plastic or metal foil called a "flyer" or a "slapper" across a gap, and its high-velocity impact on an explosive then delivers the energy and shock needed to initiate a detonation. Normally all the slapper's kinetic energy is supplied by the heating of the plasma by the current passing through it, though constructions with a "back strap" to further drive the plasma forward by magnetic field also exist. This assembly is quite efficient; up to 30% of the electrical energy can be converted to the slapper's kinetic energy. The device's name is derived from the English word 'slap'.
A pyrotechnic fastener is a fastener, usually a nut or bolt, that incorporates a pyrotechnic charge that can be initiated remotely. One or more explosive charges embedded within the bolt are typically activated by an electric current, and the charge breaks the bolt into two or more pieces. The bolt is typically scored around its circumference at the point(s) where the severance should occur. Such bolts are often used in space applications to ensure separation between rocket stages, because they are lighter and much more reliable than mechanical latches.
The terms Androgynous Peripheral Attach System (APAS), Androgynous Peripheral Assembly System (APAS) and Androgynous Peripheral Docking System (APDS) are used interchangeably to describe a Russian family of spacecraft docking mechanisms, and are also sometimes used as generic names for any docking system in that family. A system similar to APAS-89/95 is used by the Chinese Shenzhou spacecraft.
An explosive lens—as used, for example, in nuclear weapons—is a highly specialized shaped charge. In general, it is a device composed of several explosive charges. These charges are arranged and formed with the intent to control the shape of the detonation wave passing through them. The explosive lens is conceptually similar to an optical lens, which focuses light waves. The charges that make up the explosive lens are chosen to have different rates of detonation. In order to convert a spherically expanding wavefront into a spherically converging one using only a single boundary between the constituent explosives, the boundary shape must be a paraboloid; similarly, to convert a spherically diverging front into a flat one, the boundary shape must be a hyperboloid, and so on. Several boundaries can be used to reduce aberrations of the final wavefront.
An electric match is a device that uses an externally applied electric current to ignite a combustible compound.
The frangible nut is a component used in many industries, but most commonly by NASA, to sever mechanical connections. It is, by definition, an explosively-splittable nut. The bolt remains intact while the nut itself is split into two or more parts.
In pyrotechnics, a pyrotechnic initiator is a device containing a pyrotechnic composition used primarily to ignite other, more difficult-to-ignite materials, such as thermites, gas generators, and solid-fuel rockets. The name is often used also for the compositions themselves.
NASA's Christopher C. Kraft Jr. Mission Control Center, also known by its radio callsign, Houston, is the facility at the Lyndon B. Johnson Space Center in Houston, Texas, that manages flight control for the United States human space program, currently involving astronauts aboard the International Space Station (ISS). The center is in Building 30 at the Johnson Space Center and is named after Christopher C. Kraft Jr., a NASA engineer and manager who was instrumental in establishing the agency's Mission Control operation, and was the first Flight Director.
A bridgewire or bridge wire, also known as a hot bridge wire (HBW), is a relatively thin resistance wire used to set off a pyrotechnic composition serving as pyrotechnic initiator. By passing of electric current it is heated to a high temperature that starts the exothermic chemical reaction of the attached composition. After successful firing, the bridgewire melts, resulting in an open circuit.
A pyrotechnic valve, also explosive actuated valve, short pyro valve or pyrovalve is a one time use propulsion component often used to control propellant or pressurant systems aboard spacecraft or space probes. The device is activated by an electric signal, upon which one or several small explosive charges are ignited. These in turn produce high-pressure gas which either push a small, perforated piston which initially blocked the flow path of the working fluid forward until the hole aligns with the tubing, allowing the working fluid to flow, or force a sharpened piston through a weakened part of the attached tube to block the flow path of the working fluid. These two versions of pyrotechnic valves are referred to as normally-closed (NC) or normally-open (NO) valves respectively, depending on their initial state before initiation of the pyrotechnic charge. Modern pyrotechnic valves feature two redundant explosive charges in order to maximize reliability of the valve.
References
- ↑ Proceedings of Electric Initiator Symposium - 1963. Franklin Institute, Philadelphia, Pennsylvania: U.S. Army Materiel Command. 1 October 1963. pp. 3-1–3-22. Archived from the original (PDF) on 28 May 2018.
- ↑ Seeholzer, Thomas L.; Smith, Floyd Z.; Eastwood, Charles W.; Steffes, Paul R. (1 January 1995). Applications catalog of pyrotechnically actuated devices/systems (PDF). Cleveland, OH: NASA Lewis Research Center. pp. 66–67. Archived from the original (PDF) on 22 August 2022.
- 1 2 Apollo Spacecraft and Saturn V Launch Vehicle Pyrotechnics/Explosive Devices (PDF). Houston, TX: NASA, Johnson Space Center. 1 January 2009. Archived from the original (PDF) on 6 January 2022.
- ↑ Apollo Experience Report - Spacecraft Pyrotechnic Systems (PDF). Houston, TX: NASA, Lyndon B. Johnson Space Center. 1 March 1973. Archived from the original (PDF) on 12 December 2020.