Difference between revisions of "KEO"
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| − | ''' | + | A '''kerbisynchronous orbit''' ('''KSO''', sometimes '''geosynchronous orbit''', '''GSO''') is the synchronous orbit of the planet [[Kerbin]]. A spacecraft on this orbit will stay in the sky above a constant longitude, making it easy to track a satellite and contact to them. The orbital altitude is 2 868.75 km at an orbital speed of 1009.0 m/s. The surface velocity is zero when it is a stationary orbit or slightly higher. |
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| + | A special type of synchronous orbit is the '''kerbistationary orbit''' (or '''geostationary orbit'''). The inclination and eccentricity are 0 so that the satellite doesn't appear to move at all. | ||
== Maneuver Planning == | == Maneuver Planning == | ||
| + | The basic maneuver plan for reaching this orbit is to first achieve a low energy orbit (LEO) and then perform two maneuvers to execute a [[w:Hohmann transfer|Hohmann transfer]]. The first one called the periapsis maneuver is raising the apoapsis to the required altitude for a synchronous orbit. This places the spacecraft on a '''kerbisynchronous transfer orbit''' (KTO). The second one is at the apoapsis. | ||
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| + | Depending on the required orbit the second burn also includes nearly all of the plane change to reduce the equatorial inclination to zero.{{cn}}<!-- Does the oberth effect maybe help and you should fix your orbit at the periapsis?--> For stationary orbits the periapsis maneuver should be executed when crossing the equatorial plane. Since the Kerbal Space Center is on the equator, the timing and trigonometry may be skipped. | ||
The following are instantaneous impulse calculations for equatorial low energy orbits, and therefore the real maneuvers will always be somewhat more than these values. | The following are instantaneous impulse calculations for equatorial low energy orbits, and therefore the real maneuvers will always be somewhat more than these values. | ||
{| class="wikitable" | {| class="wikitable" | ||
| − | + | ! LEO Altitude | |
| − | !LEO Altitude | ||
! Periapsis | ! Periapsis | ||
! Apoapsis | ! Apoapsis | ||
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|} | |} | ||
| − | For direct launches, transfers from the lowest orbits will be more efficient because they require less delta-v to reach from the surface of Kerbin. | + | For direct launches, transfers from the lowest orbits will be more efficient because they require less delta-v to reach from the surface of Kerbin. Higher LEOs may be preferable if the spacecraft is visiting a tug or space station and requires altitude above the atmosphere to execute a rendezvous. These maneuver plans may also be useful for one who wishes to boost a large space station assembled on LEO to KEO. |
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| − | |||
| − | + | == Other celestial bodies == | |
| + | In theory those orbits also exists for other celestial bodies, but may be outside the sphere of influence. | ||
| − | + | == See also == | |
| + | * {{Wikipedia|Geostationary orbit}} | ||
| + | * {{Wikipedia|Geosynchronous orbit}} | ||
| + | * {{Wikipedia|Synchronous orbit}} | ||
Revision as of 18:06, 20 July 2013
A kerbisynchronous orbit (KSO, sometimes geosynchronous orbit, GSO) is the synchronous orbit of the planet Kerbin. A spacecraft on this orbit will stay in the sky above a constant longitude, making it easy to track a satellite and contact to them. The orbital altitude is 2 868.75 km at an orbital speed of 1009.0 m/s. The surface velocity is zero when it is a stationary orbit or slightly higher.
A special type of synchronous orbit is the kerbistationary orbit (or geostationary orbit). The inclination and eccentricity are 0 so that the satellite doesn't appear to move at all.
Maneuver Planning
The basic maneuver plan for reaching this orbit is to first achieve a low energy orbit (LEO) and then perform two maneuvers to execute a Hohmann transfer. The first one called the periapsis maneuver is raising the apoapsis to the required altitude for a synchronous orbit. This places the spacecraft on a kerbisynchronous transfer orbit (KTO). The second one is at the apoapsis.
Depending on the required orbit the second burn also includes nearly all of the plane change to reduce the equatorial inclination to zero.[citation needed] For stationary orbits the periapsis maneuver should be executed when crossing the equatorial plane. Since the Kerbal Space Center is on the equator, the timing and trigonometry may be skipped.
The following are instantaneous impulse calculations for equatorial low energy orbits, and therefore the real maneuvers will always be somewhat more than these values.
| LEO Altitude | Periapsis | Apoapsis | Total |
|---|---|---|---|
| 70km | 676.6 m/s | 434.9 m/s | 1111.5 m/s |
| 90km | 659.6 m/s | 427.8 m/s | 1087.4 m/s |
| 100km | 651.5 m/s | 424.3 m/s | 1075.8 m/s |
| 120km | 635.5 m/s | 417.4 m/s | 1052.9 m/s |
| 150km | 612.7 m/s | 407.3 m/s | 1020.0 m/s |
| 200km | 577.4 m/s | 391.3 m/s | 968.7 m/s |
| 300km | 515.3 m/s | 361.3 m/s | 876.6 m/s |
For direct launches, transfers from the lowest orbits will be more efficient because they require less delta-v to reach from the surface of Kerbin. Higher LEOs may be preferable if the spacecraft is visiting a tug or space station and requires altitude above the atmosphere to execute a rendezvous. These maneuver plans may also be useful for one who wishes to boost a large space station assembled on LEO to KEO.
Other celestial bodies
In theory those orbits also exists for other celestial bodies, but may be outside the sphere of influence.
See also
- Geostationary orbit on Wikipedia
- Geosynchronous orbit on Wikipedia
- Synchronous orbit on Wikipedia
