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An apogee kick motor (AKM) is a rocket motor that is regularly employed on artificial satellites to provide the final impulse to change the trajectory from the transfer orbit into its final orbit (most commonly circular). 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 apogee kick motor is used, for example, for satellites launched into a geostationary orbit. As the vast majority of geostationary satellite launches are carried out from spaceports at a significant distance away from Earth's equator, the carrier rocket often only launches the satellite into an orbit with a non-zero inclination approximately equal to the latitude of the launch site. This orbit is commonly known as a "geostationary transfer orbit" 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. [1] 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". [1]
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. [2]
A Star 48 kick motor was used to launch the New Horizons spacecraft towards Pluto. [3]
Energia was a 1980s super-heavy lift launch vehicle. It was designed by NPO Energia of the Soviet Union as part of the Buran program for a variety of payloads including the Buran spacecraft. Control system main developer enterprise was the Khartron NPO "Electropribor". The Energia used four strap-on boosters each powered by a four-chamber RD-170 engine burning kerosene/LOX, and a central core stage with four single-chamber RD-0120 (11D122) engines fueled by liquid hydrogen/LOX.
A geosynchronous orbit is an Earth-centered orbit with an orbital period that matches Earth's rotation on its axis, 23 hours, 56 minutes, and 4 seconds. The synchronization of rotation and orbital period means that, for an observer on Earth's surface, an object in geosynchronous orbit returns to exactly the same position in the sky after a period of one sidereal day. Over the course of a day, the object's position in the sky may remain still or trace out a path, typically in a figure-8 form, whose precise characteristics depend on the orbit's inclination and eccentricity. A circular geosynchronous orbit has a constant altitude of 35,786 km (22,236 mi).
A trans-lunar injection (TLI) is a propulsive maneuver used to set a spacecraft on a trajectory that will cause it to arrive at the Moon.
In astronautics, the Hohmann transfer orbit is an orbital maneuver used to transfer a spacecraft between two orbits of different altitudes around a central body. Examples would be used for travel between low Earth orbit and the Moon, or another solar planet or asteroid. In the idealized case, the initial and target orbits are both circular and coplanar. The maneuver is accomplished by placing the craft into an elliptical transfer orbit that is tangential to both the initial and target orbits. The maneuver uses two impulsive engine burns: the first establishes the transfer orbit, and the second adjusts the orbit to match the target.
A geostationary transfer orbit (GTO) or geosynchronous transfer orbit 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 for reaching their final orbit.
Delta-v, symbolized as and pronounced delta-vee, as used in spacecraft flight dynamics, is a measure of the impulse per unit of spacecraft mass that is needed to perform a maneuver such as launching from or landing on a planet or moon, or an in-space orbital maneuver. It is a scalar that has the units of speed. As used in this context, it is not the same as the physical change in velocity of said spacecraft.
In astrodynamics and aerospace, a delta-v budget is an estimate of the total change in velocity (delta-v) required for a space mission. It is calculated as the sum of the delta-v required to perform each propulsive maneuver needed during the mission. As input to the Tsiolkovsky rocket equation, it determines how much propellant is required for a vehicle of given empty mass and propulsion system.
In spaceflight, an orbital maneuver is the use of propulsion systems to change the orbit of a spacecraft. For spacecraft far from Earth an orbital maneuver is called a deep-space maneuver (DSM).
GSAT-1 was an experimental communications satellite launched aboard the maiden flight of the GSLV rocket. The spacecraft was equipped with instrumentation to test Pulse-code modulation (PCM) transmitting on S-band frequencies and transponders operating in the C-band. The spacecraft was unable to complete its mission after a launch failure left it in a lower than planned orbit and propulsion issues prevented the satellite from correcting this via its own maneuvering system.
A supersynchronous orbit is either an orbit with a period greater than that of a synchronous orbit, or just an orbit whose major axis is larger than that of a synchronous orbit. A synchronous orbit has a period equal to the rotational period of the body which contains the barycenter of the orbit.
A ground track or ground trace is the path on the surface of a planet directly below an aircraft's or satellite's trajectory. In the case of satellites, it is also known as a suborbital track or subsatellite track, and is the vertical projection of the satellite's orbit onto the surface of the Earth.
A parking orbit is a temporary orbit used during the launch of a spacecraft. A launch vehicle boosts into the parking orbit, then coasts for a while, then fires again to enter the final desired trajectory. The alternative to a parking orbit is direct injection, where the rocket fires continuously until its fuel is exhausted, ending with the payload on the final trajectory. The technology was first used by the Soviet Venera 1 mission to Venus.
The Intelsat VI series of satellites were the 8th generation of geostationary communications satellites for the Intelsat Corporation. Designed and built by Hughes Aircraft Company (HAC) in 1983-1991, there were five VI-series satellites built: 601, 602, 603, 604, and 605.
An orbital propellant depot is a cache of propellant that is placed in orbit around Earth or another body to allow spacecraft or the transfer stage of the spacecraft to be fueled in space. It is one of the types of space resource depots that have been proposed for enabling infrastructure-based space exploration. Many different depot concepts exist depending on the type of fuel to be supplied, location, or type of depot which may also include a propellant tanker that delivers a single load to a spacecraft at a specified orbital location and then departs. In-space fuel depots are not necessarily located near or at a space station.
THAICOM 6 is a Thai satellite of the Thaicom series, operated by Thaicom Public Company Limited, a subsidiary of INTOUCH headquartered in Bangkok, Thailand. THAICOM 6 is colocated with Thaicom 5 at 78.5 degrees East, in geostationary orbit. The total cost for the satellite is US$160 million.
The Star is a family of US solid-propellant rocket motors originally developed by Thiokol and used by many space propulsion and launch vehicle stages. They are used almost exclusively as an upper stage, often as an apogee kick motor.
A liquid apogee engine (LAE), or apogee engine, refers to a type of chemical rocket engine typically used as the main engine in a spacecraft.
GSAT-6A was a communication satellite launched by the Indian Space Research Organisation (ISRO) It featured a 6-metre (20 ft) unfurlable S-band antenna similar to the one used on GSAT-6. Around 17 minutes after lift-off, the three stage GSLV Mk.II rocket flying on GSLV F08 mission successfully injected the satellite into a geosynchronous transfer orbit. Due to power failure during its orbit raising burns the communication was lost with GSAT-6A before it could reach its final circular geostationary orbit (GSO).
The Integrated Apogee Boost Stage was an American rocket stage used for the launch of Defense Satellite Communications System III satellites to geostationary orbit when using a launch vehicle without an upper stage capable of delivering them there directly. Earlier DSCS III satellites had launched on the Titan 34D and Space Shuttle Atlantis, which were capable of delivering them directly to geostationary orbit - as such, the satellites were not capable of moving from geostationary transfer orbit to geostationary orbit themselves. Because of this, launch of these satellites on the Atlas II and Delta IV families required an apogee kick stage - the IABS - to be added to the satellite. The IABS was developed by GE Astro Space, who also manufactured the DSCS III satellites it was designed for.