Apogee kick on:
[Wikipedia]
[Google]
[Amazon]
An apogee kick motor (AKM) is a
Kick In the Apogee: 40 years of upper stage applications for solid rocket motors, 1957–1997
, 33rd AIAA Joint Propulsion Conference, July 4, 1997
abstract
Retrieved 18 July 2017. When the satellite reaches its orbit's apogee position, the AKM is ignited, transforming the elliptical orbit into a circular orbit, while at the same time bringing the inclination to around zero degrees, thereby accomplishing the insertion into a geostationary orbit. This process is called an "apogee kick". More generally, firing a rocket engine to place a vehicle into the desired final orbit from a transfer orbit is labelled an "orbital insertion burn" or, if the desired orbit is circular, a ''circularization burn.'' For orbits around bodies other than Earth, it may be referred to as an ''apoapsis'' burn. The amount of fuel carried on board a satellite directly affects its lifetime, therefore it is desirable to make the apogee kick maneuver as efficient as possible. The mass of most geostationary satellites at the beginning of their operational life in geostationary orbit is typically about half that when they separated from their vehicle in geostationary transfer orbit, with the other half having been fuel expended in the apogee kick maneuver.
An apogee kick motor (AKM) is a rocket motor
A rocket engine uses stored rocket propellants as the reaction mass for forming a high-speed propulsive jet of fluid, usually high-temperature gas. Rocket engines are reaction engines, producing thrust by ejecting mass rearward, in accordance ...
that is regularly employed on artificial satellites to provide the final impulse to change the trajectory from the transfer orbit into its final (most commonly circular) orbit. For a satellite launched from the Earth, the rocket firing is done at the highest point of the transfer orbit, known as the apogee
An apsis (; ) is the farthest or nearest point in the orbit of a planetary body about its primary body. For example, the apsides of the Earth are called the aphelion and perihelion.
General description
There are two apsides in any el ...
.
An apogee kick motor is used, for example, for satellites launched into a geostationary orbit
A geostationary orbit, also referred to as a geosynchronous equatorial orbit''Geostationary orbit'' and ''Geosynchronous (equatorial) orbit'' are used somewhat interchangeably in sources. (GEO), is a circular geosynchronous orbit in altitu ...
. As the vast majority of geostationary satellite launches are carried out from spaceport
A spaceport or cosmodrome is a site for launching or receiving spacecraft, by analogy to a seaport for ships or an airport for aircraft. The word ''spaceport'', and even more so ''cosmodrome'', has traditionally been used for sites capable ...
s at a significant distance away from Earth's equator
The equator is a circle of latitude, about in circumference, that divides Earth into the Northern and Southern hemispheres. It is an imaginary line located at 0 degrees latitude, halfway between the North and South poles. The term can also ...
, the carrier rocket often only launches the satellite into an orbit with a non-zero inclination approximately equal to the latitude
In geography, latitude is a coordinate that specifies the north– south position of a point on the surface of the Earth or another celestial body. Latitude is given as an angle that ranges from –90° at the south pole to 90° at the north ...
of the launch site. This orbit is commonly known as a "geostationary transfer orbit
A geosynchronous transfer orbit or geostationary transfer orbit (GTO) is a type of geocentric orbit. Satellites that are destined for geosynchronous (GSO) or geostationary orbit (GEO) are (almost) always put into a GTO as an intermediate step ...
" or a "geosynchronous transfer orbit". The satellite must then provide thrust to bring forth the needed delta v to reach a geostationary orbit. This is typically done with a fixed onboard apogee kick motor.Jonathan McDowell,Kick In the Apogee: 40 years of upper stage applications for solid rocket motors, 1957–1997
, 33rd AIAA Joint Propulsion Conference, July 4, 1997
abstract
Retrieved 18 July 2017. When the satellite reaches its orbit's apogee position, the AKM is ignited, transforming the elliptical orbit into a circular orbit, while at the same time bringing the inclination to around zero degrees, thereby accomplishing the insertion into a geostationary orbit. This process is called an "apogee kick". More generally, firing a rocket engine to place a vehicle into the desired final orbit from a transfer orbit is labelled an "orbital insertion burn" or, if the desired orbit is circular, a ''circularization burn.'' For orbits around bodies other than Earth, it may be referred to as an ''apoapsis'' burn. The amount of fuel carried on board a satellite directly affects its lifetime, therefore it is desirable to make the apogee kick maneuver as efficient as possible. The mass of most geostationary satellites at the beginning of their operational life in geostationary orbit is typically about half that when they separated from their vehicle in geostationary transfer orbit, with the other half having been fuel expended in the apogee kick maneuver.
See also
* Advanced Cryogenic Evolved Stage *Centaur
A centaur ( ; grc, κένταυρος, kéntauros; ), or occasionally hippocentaur, is a creature from Greek mythology with the upper body of a human and the lower body and legs of a horse.
Centaurs are thought of in many Greek myths as bein ...
* Hohmann transfer orbit
* Liquid apogee engine
* List of upper stages
*Multistage rocket
A multistage rocket or step rocket is a launch vehicle that uses two or more rocket ''stages'', each of which contains its own engines and propellant. A ''tandem'' or ''serial'' stage is mounted on top of another stage; a ''parallel'' stage i ...
* Space tug
References
{{DEFAULTSORT:Apogee Kick Motor Rocketry Rocket engines