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K

  
k
   (Space Flight Glossary - JPL)
Kilo (thousand).
K-band
   (NASA SP-7, 1965)
A frequency band used in radar extending approximately from 10.9 gigacycles per second to 36 gigacycles per second.
K-corona
   (NASA SP-7, 1965)
That portion of the radiation from the solar corona consisting of the continuous spectrum scattered by electrons.
K-display
   (NASA SP-7, 1965)
In radar, a modified A-display in which a target appears as a pair of vertical deflections or blips instead of a single deflection. When the radar antenna is correctly pointed at the target in azimuth, the blips are of equal height. When not correctly pointed, the difference in blip height is an indication of direction and magnitude of azimuth pointing error. Also called K-scan, K-scope, K-indicator.
K-indicator
   (NASA SP-7, 1965)
= K-display.
K-indices
   (NASA SP-7, 1965)
= magnetic K-indices.
K-scan
   (NASA SP-7, 1965)
= K-display.
K-scope
   (NASA SP-7, 1965)
= K-display.
kaolinite
   (NASA Thesaurus)
A hydrous silicate of aluminum. It constitutes the principle mineral in kaolin.
Karman street
   (NASA SP-7, 1965)
= Karman vortex street.
Karman vortex street
   (NASA Thesaurus / NASA SP-7, 1965)
(After Theodore von Karman, 1881-1963, Hungarian-born American scientist). A double trail of vortices formed alternately on both sides of a cylinder or similar body moving at right angles to its axis through a fluid, the cortices in one row rotating in a direction opposite to that of the other row.
kelvin
   (Imagine the Universe Dictionary - NASA GSFC)
A temperature scale often used in sciences such as astronomy. The fundamental SI unit of thermodynamic temperature defined as 1/273.16 of the thermodynamic temperature of the triple point of water. The Kelvin temperature scale is just like the Celsius scale except that the freezing point of water, zero degrees Celsius, is equal to 273 degrees Kelvin. [ K = C + 273o => F = 9/5C + 32o]
Kelvin scale
   (NASA SP-7, 1965)
= Kelvin temperature scale.
Kelvin temperature scale
   (NASA SP-7, 1965)
(abbr K)
An absolute temperature scale independent of the thermometric properties of the working substance. On this scale, the difference between two temperatures T1 and T2 is proportional to the heat converted into mechanical work by a Carnot engine operating between the isotherms and adiabats through T1 and T2. Also called absolute temperature scale, thermodynamic temperature scale.
For convenience the Kelvin is identified with the Celsius degree. The ice point in the Kelvin scale is 273.15 degrees K. The triple point of water, the fundamental reference points, is 273.16 degrees K. See absolute zero, approximate absolute temperature scale, Rankine temperature scale.
Kelvin Units
   (Global Land Information System Glossary - USGS)
A Kelvin Unit refers to a thermometric scale in which the degree intervals are equal to those of the Celsius scale and in which zero(0) degrees equals -273.15 degrees Celsius (absolute zero).
Kennelly-Heaviside layer
   (NASA SP-7, 1965)
= E layer.
Kepler equation
   (NASA SP-7, 1965)
In celestial mechanics M = E - e sin E where M is mean anomaly; E is eccentric anomaly; and e is eccentricity of the orbital ellipse. See anomaly, note.
Kepler laws
   (NASA Thesaurus / NASA SP-7, 1965)
The three empirical laws governing the motions of planets in their orbits, discovered by Johannes Kepler (1571-1630). These are: (a) the orbits of the planets are ellipses, with the sun at a common focus; (b) as a planet moves in its orbit, the line joining the planet and sun sweeps over equal areas in equal intervals of time (also called law of equal areas ); (c) the squares of the periods of revolution of any two planets are proportional to the cubes of their mean distances from the sun.
Kepler planetary laws
   (NASA SP-7, 1965)
= Kepler laws.
Keplerian
   (NASA SP-7, 1965)
Pertaining to motion in conformance with Kepler laws, as Keplerian trajectory, Keplerian ellipse.
kerogen
   (NASA Thesaurus)
Fossilized insoluble organic material found in sedimentary rocks, usually shales, which can be converted to petroleum products by distillation.
ketones
   (NASA Thesaurus)
A class of organic compounds possessing a carbonyl group attached to two hydrocarbon groups.
kettles (geology)
   (NASA Thesaurus)
Steepsided, usually basin or bowlshaped holes or depressions, commonly without surface drainage, in glacial drift deposits (especially outwash and kame fields). Kettles often contain lakes or swamps; formed by the melting of large detached blocks of stagnant ice (left behind by retreating glaciers) that had been wholly or partly buried by glacial drift. Kettles range in depth from about a meter to as much as 13 km. Thoreau's Walden Pond is an example.
Kevlar (trademark)
   (NASA Thesaurus)
A Dupont synthetic textile material, lightweight and nonflammable, and with high impact resistance.
kg
   (Space Flight Glossary - JPL)
Kilogram, the metric standard unit of mass, based on the mass of a metal cylinder kept in France. See gram.
kHz
   (Space Flight Glossary - JPL)
kilohertz.
kilo
   (NASA SP-7, 1965)
(abbr k)
Prefix meaning multiplied by 1000.
kilocalorie
   (NASA SP-7, 1965)
(abbr kcal)
See calorie.
kilocycle
   (NASA SP-7, 1965)
(abbr kc)
One thousand cycles or 1000 cycles per second.
kilogram
   (High Energy Astrophysics Dictionary- GSFC)
One kilogram is equivalent to 1,000 grams or 2.2 pounds; the mass of a liter of water. Abbreviated "kg", it is the fundamental standard international (SI) unit of mass, it is the only SI unit still maintained by a physical artifact: a platinum-iridium bar kept in the International Bureau of Weights and Measures at Sevres, France.
kilogram
   (NASA SP-7, 1965)
(abbr kg)
The unit of mass in the metric system; the mass of the International Prototype Kilogram, a cylinder of platinum-iridium alloy, stored at Seures, France, by the International Bureau of Weights and Measures.
kilogram calorie
   (NASA SP-7, 1965)
(abbr kg-cal, Kcal, Cal)
See calorie.
kilomegacycle
   (NASA SP-7, 1965)
= gigacycle.
kilometer
   (High Energy Astrophysics Dictionary- GSFC)
One kilometer is equivalent to 1,000 meters or 0.62 miles. Abbreviated "km".
kilometer
   (NASA SP-7, 1965)
(abbr km)
A unit of distance in the metric system.
1 kilometer = 3280.8 feet = 1093.6 yards = 1000 meters = 0.62137 statute miles = 0.53996 nautical miles.
kilometric waves
   (NASA Thesaurus)
Electromagnetic waves with wavelengths between 1,000 and 10,000 meters.
kilometric waves
   (NASA SP-7, 1965)
See frequency bands.
kiloparsec
   (High Energy Astrophysics Dictionary- GSFC)
A distance equal to 1000 parsecs.
kilowatt-hour
   (From Stargazers to Starships Glossary - GSFC)
The amount of energy supplied by one kilowatt (1000 watt) for 1 hour (3600 seconds), equal to 3 600 000 joule. The abbreviation is KwH.
kinematic eddy viscosity
   (NASA SP-7, 1965)
See kinematic viscosity.
kinematic viscosity
   (NASA SP-7, 1965)
(symbol nu)
A coefficient defined as the ratio of the dynamic viscosity of a fluid to its density.
The kinematic viscosity of most gases increases with increasing temperature and decreasing pressure. For dry air at 0º C, the kinematic viscosity is about 0.13 square centimeter per second. In the theory of atmospheric turbulence the kinematic viscosity is usually replaced by the kinematic eddy viscosity to account for the increased internal friction due to turbulence.
kinematics
   (NASA Thesaurus / NASA SP-7, 1965)

The branch of mechanics dealing with the description of the motion of bodies or fluids without reference to the forces producing the motion.
kinetic energy
   (NASA Thesaurus / NASA SP-7, 1965)
(symbol Ek)
The energy which a body possesses as a consequence of its motion, defined as one-half the product of its mass m and the square of its speed v, one half m v squared. The kinetic energy per unit volume of a fluid parcel is the one half rho nu squared , where rho is the density and v the speed of the parcel. See potential energy.
For relativistic speeds the kinetic energy is given by

E sub k equals m c squared minus m sub zero c squared

where c is the velocity of light in a vacuum, m0 is the rest mass, and m is the moving mass.
kinetic pressure
   (Plasma Physics and Fusion Energy Glossary)
Density of kinetic energy (energy in the thermal motions of the plasma particles). For an ideal plasma, pressure is given by p = nkT, that is: pressure = (density) * (Boltzmann's constant)* (temperature)
kinetic pressure
   (NASA SP-7, 1965)
= dynamic pressure.
kinetic theory
   (NASA Thesaurus / NASA SP-7, 1965)
The derivation of the bulk properties of fluids from the properties of their constituent molecules, their motions, and interactions.
kinetic-energy equation
   (NASA SP-7, 1965)
= mechanical-energy equation.
kink instability
   (NASA SP-7, 1965)
In plasma physics, a kinking or bending of a current-carrying filament in the pinch effect geometry.
If a slight bend forms in the plasma column of a pinch, the magnetic forces are such as to increase the bend and the column is unstable.
kink mode
   (Plasma Physics and Fusion Energy Glossary)
Class of MHD instabilities which sometimes develop in a thin plasma column carrying a strong axial current. If a kink begins to develop in such a column the magnetic forces on the inside of the kink become larger than those on the outside, so that in general it tends to grow in magnitude. The column then becomes unstable and can be displaced into the walls of the discharge chamber, causing a disruption.
kipuka
   (Photoglossary of Volcanic Terms - USGS)
A Hawaiian term for an "island" of land completely surrounded by one or more younger lava flows. A kipuka forms when lava encircles a hill or a slight rise in the ground as it moves downslope or across relatively flat ground. Because they are surrounded by more recent flows, kipukas are often covered with mature vegetation.
Kirchhoff law
   (NASA SP-7, 1965)
The radiation law which states that at a given temperature the ratio of the emissivity to the absorptivity for a given wavelength is the same for all bodies and is equal to the emissivity of an ideal blackbody at that temperature and wavelength.
Loosely put, this important law asserts that good absorbers of a given wavelength are also good emitters of that wavelength. It is essential to note that the Kirchhoff law relates absorption and emission at the same wavelength and at the same temperature. Also called Kirchhoff radiation law.
Kirchhoff law of radiation
   (NASA Thesaurus)
The radiation law which states that at a given temperature the ratio of the emissivity to the absorptivity for a given wavelength is the same for all bodies and is equal to the emissivity of an ideal blackbody at that temperature and wavelength.
Kirchhoff's law of radiation
   (Imagine the Universe Dictionary - NASA GSFC)
The emissivity of a body is equal to its absorbance at the same temperature.
klystron
   (NASA Thesaurus / NASA SP-7, 1965)
An electron tube for converting direct-current energy into radio frequency energy by alternately speeding up and slowing down the electrons. See magnetron.
knot
   (NASA SP-7, 1965)
A nautical mile per hour, 1.1508 statute miles per hour.
knowledge bases (artificial intelligence)
   (NASA Thesaurus)
Facts, assumptions, beliefs, and heuristics, used in dealing with a database to achieve desired results such as a diagnosis, an interpretation, or a solution to a problem.
knowledge representation
   (NASA Thesaurus)
The use of symbolic data structures to represent knowledge so that a computer can manipulate them.
Knudsen flow
   (NASA SP-7, 1965)
The flow of gases through ducts and tubes under conditions intermediate between laminar viscous flow and molecular flow. Also called transition flow.
Knudsen gage
   (NASA Thesaurus / NASA SP-7, 1965)
A gage which measures pressure in terms of the net rate of transfer of momentum by molecules between two surface maintained at different temperatures and separated by a distance smaller than the mean free path of the gas molecules. Also called radiometer vacuum gage.
Various types of Knudsen gage are distinguished by the names of the inventors and differ mainly in the shape and method of suspension of the movable element.
Knudsen number
   (NASA SP-7, 1965)
A number used to describe the flow of a low density gas, equal to the ratio lambda over l where lambda is the mean free path of the gas molecule and l is a characteristic length, such as boundary layer thickness, or apparatus dimension.
The Knudsen number is used most commonly to define the extend to which the gas behaves like a collection of independent particles (free-molecule regime, Knudsen number much larger than unity), or like a viscous fluid (continuous regime, Knudsen number much smaller than unity). Intermediate regimes are termed transition region, and slip flow region. See rarefied gas dynamics, note.
Knudsen rate of evaporation
   (NASA SP-7, 1965)
= maximum evaporation rate.
Kondo effect
   (NASA Thesaurus)
Change in superconductivity characteristics resulting from magnetic impurities in the compounds involved.
Korteweg-Devries equation
   (NASA Thesaurus)
The mathematical representation describing the propagation of long waves of small but finite amplitude.
Kraft process (woodpulp)
   (NASA Thesaurus)
Woodpulping process in which sodium sulfate is used in the caustic soda pulp-digestion liquor. Also known as sulfate pulping or Kraft pulping.
Kramers-Kronig formula
   (NASA Thesaurus)
The relationship between the attenuation coefficient and the dispersion (frequency dependent phase velocity) for viscoelastic waves.
kreep
   (NASA Thesaurus)
A yellow-brown glassy lunar mineral enriched in potassium, rare earth elements, and phosphate.
kriging
   (NASA Thesaurus)
A method of providing unbiased estimates of variables in regions where the available data exhibit spatial autocorrelation, and these estimates are obtained in such a way that they have minimum variance.
krypton fluoride lasers
   (NASA Thesaurus)
Rare gas halide ultraviolet stimulated emission devices in which krypton fluoride is the active lasing medium.
KSC
   (Space Flight Glossary - JPL)
Kennedy Space Center, Cape Canaveral, Florida.
kurtosis
   (NASA Thesaurus)
In statistics, the extent to which a frequency distribution is peaked or concentrated about the mean; it is sometimes defined as the ratio of the fourth moment of the distribution to the square of the second moment.
KWF
   (Space Flight Glossary - JPL)
Keyword file of events listing DSN station activity.
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