https://wiki.kerbalspaceprogram.com/api.php?action=feedcontributions&user=Danny&feedformat=atomKerbal Space Program Wiki - User contributions [en]2024-03-28T10:30:38ZUser contributionsMediaWiki 1.29.0https://wiki.kerbalspaceprogram.com/index.php?title=Center_of_thrust&diff=57482Center of thrust2015-02-09T05:52:08Z<p>Danny: </p>
<hr />
<div>[[File:Cot icon.png|framed|left|Icon]]<br />
<br />
[[File:Com and cot.png|thumb|The thrust points away from the center of mass]]<br />
{{Stub}}<br />
<br />
The '''center of thrust''' (abbreviated '''COT''') is the direction in which a craft's thrust is acting and the point at which the overall thrust is effectively acting. Because it also has a direction component, it's usually called the '''thrust vector'''<!-- at least in real life -->. The thrust vector should point directly toward or directly away from the craft's [[center of mass]], or else the thrust will cause the craft to rotate (some of the force of the thrust will cause a torque). Such torque can sometimes be balanced out by [[control surface]]s, [[RCS]], reaction wheels, or other additional torque forces acting on the craft. Although a thrust imbalance can be counteracted, it is more fuel efficient to make a balanced rocket with its COM in-line with its COT.<br />
<br />
It is important to note that the COT depends on all running [[engine]]s on the [[craft]], and not just the engines in any individual stage. The center of thrust will change when any single engine's thrust changes due to activation, throttling, shutdown, or any other change. This includes when a craft's configuration changes due to jettisoning an engine or docking with another craft that has an active engine.<br />
<br />
The center of thrust is one of the three “centers” displayed in the [[VAB]] and [[Spaceplane Hangar]] along with the [[center of lift]] and [[center of mass]], abbreviated COL and COM respectively.<br />
<br />
== Pendulum rocket fallacy ==<br />
<br />
<br />
It is tempting to think about placing the engines of a rocket at the top, so that the thrust vector points down toward the center of mass. This way, it seems that the engines will pull the rocket up, and that the rocket's weight will keep it hanging directly under the engines, so that it stays upright. Unfortunately, this is not true. Since the rocket's weight acts as a force exactly through its center of mass, gravity doesn't provide any torque to oppose the rotation of the rocket. Any imperfection in the alignment of the thrust vector, or any outside torques, will still cause rotation. This is equally problematic regardless of the location of the engines. The stability of a rocket ultimately depends on its ability to actively counteract imperfections. In KSP, this is most often accomplished by using engines with thrust vectoring. When such an engine gimbals, it slightly modifies the thrust vector. [[SAS]] uses this as needed to correct for imbalances, along with [[RCS]], [[reaction wheel]]s, and [[control surface]]s.<br />
<br />
<br />
A highly unbalanced rocket (e.g. a rocket that loses one of multiple engines due to [[rapid unplanned disassembly]]) might produce so much torque at full throttle that its other controls are too weak to prevent it from rotating. This means it will be mostly uncontrollable. It might be possible, however, to control such a craft by throttling the engines down to a point where the torque they produce is no greater than the torque from SAS.<br />
<br />
== See also ==<br />
* [[Center of lift]]<br />
* [[Center of mass]]<br />
* {{Wikipedia|Pendulum rocket fallacy}}</div>Dannyhttps://wiki.kerbalspaceprogram.com/index.php?title=Duna&diff=57480Duna2015-02-09T03:36:11Z<p>Danny: /* Atmosphere */</p>
<hr />
<div>{{Infobox/Body}}<br />
<br />
'''Duna''' is the fourth planet of the [[Kerbol System|Kerbol star system]] and [[w:Mars|Mars]] analog for Kerbal Space Program. It is mostly red with polar icecaps and has one natural satellite, the [[moon]] '''[[Ike]]'''. Ike's size and proximity tidally locks it and Duna to each other.<br />
<br />
With proper [[aerobraking]], a round trip from [[Kerbin]] to Duna's [[orbit]] and back requires roughly 1700&nbsp;m/s of [[Terminology#Physics|delta-v]], less than a round trip to any other planet. Duna is often the easiest planet to [[encounter]] because its orbital inclination is low.<br />
<br />
There is a [[tutorial]] about [[Tutorial:How to get to Duna|Traveling to Duna and Back]].<br />
<br />
== In-game Description ==<br />
<br />
{{Quote<br />
<br />
|Also known as the red dot that you can see if you squint at it really hard, Duna has long been a wonder to Kerbalkind. <br><br> The planet has been held in much awe due to its striking red color and stark contrast to the color green.<br />
<br />
|Kerbal Astronomical Society}}<br />
<br />
== Topography ==<br />
[[File:Duna Topo ISA 3200x1600 compressed.png|thumb|left|A topographic map of Duna made with the ISA MapSat plugin]]<br />
Duna's terrain ranges in altitude from 124 to 8264 meters. Its mountain ranges are a peril to landing [[craft]], due to their steepness and the limited [[aerobraking]] that is possible in Duna's tenuous [[atmosphere]] at such altitudes.<br />
<br />
Duna has several craters. They appear quite eroded, presumably by the wind.<br />
<br />
Several [[w:Lunar maria|maria]] (large regions of dark soil) are at exactly 0 meters altitude {{deprecated}}. Their low altitude allows for more aerobraking, and the flatness of the terrain makes them easy but boring landing locations. These may have been lakes when the planet may have had liquid on its surface in the past.<br />
<br />
Duna's surface contains [[List of easter eggs#Duna|anomalous features]].<br />
<br />
== Biomes==<br />
Duna has 5 [[biome]]s.<br />
<br />
=== Biome list ===<br />
{{Biome list|<br />
* Poles<br />
* Highlands<br />
* Midlands<br />
* Lowlands<br />
* Craters}}<br />
<br />
== Atmosphere ==<br />
[[File:Atmosphere kerbin duna.png|thumb|left|A comparison of the atmospheres of Duna and Kerbin]]<br />
[[File:Duna north pole.png|thumb|left|Duna's north pole]]<br />
<br />
Duna's [[atmosphere]] begins at 41,446 m. It is only 20% as dense as [[Kerbin|Kerbin's]] at sea level altitude and is even less dense relative to Kerbin at higher altitudes. At Duna's highest peak, atmospheric density is only 21% of that at sea level. For comparison, on Kerbin, the atmosphere at the highest peaks is 45% as thick as at sea level. This low density will cause [[parachute]]s to semi-deploy much lower, just over 10&nbsp;km for the [[Mk25 Parachute]], and just under 9&nbsp;km for all the other parachutes.<br />
<br />
Duna has the thinnest significant atmosphere of all bodies in the Kerbol system. Even [[Jool]]'s moon [[Laythe]] has a denser and higher atmosphere. The atmosphere appears to have a reddish or brownish color, both from the surface and from space. The atmosphere has this color even over the poles, where the surface is white.<br />
<br />
=== Landing ===<br />
[[Aerobraking]] can save fuel by reducing orbital and surface velocity greatly. An aerobraking maneuver should maximize time spent in the atmosphere by entering at a shallow angle and aiming for a landing location in a low-lying area. One estimate for a good aerobraking height is 13,000 meters, which will then allow a relatively low delta-V burn at the apoapsis to create a stable orbit safely within Ike's reign of chaos.<br />
<br />
Like all atmospheres in the game, Duna's atmosphere fades exponentially with increasing altitude (with a scale height of 3000 m). In general, the atmospheric pressure on Duna at an altitude expressed in meters is:<ref>A [[LV-N Atomic Rocket Motor]] has a specific impulse of 220 in 1 atm, 800 in vacuum, and the following at various Duna altitudes:<br />
{| class="wikitable"<br />
! altitude (m)<br />
| 2 || 100 || 300 || 500 || 1460 || 2420 || 3000 || 4272 || 5000 || 10000<br />
|-<br />
! specific impulse<br />
| 684.1 || 687.8 || 695.1 || 701.8 || 728.7 || 748.2 || 757.3 || 772.1 || 778.1 || 795.9<br />
|}</ref><br />
<br />
: <math>p_d = 0.2 \text{atm} \ e^\frac{-altitude}{3000 \text{m}}</math><br />
<br />
Although parachutes will deploy on Duna, the atmosphere is so thin that they are usually unable to slow a craft to a safe landing velocity and must be assisted with engines.<br />
<br />
[[File:Duna colony.png|thumb|A nine Kerbal colony on Duna]]<br />
<br />
=== Flying ===<br />
<br />
Below 5&nbsp;km Duna's atmosphere is thick enough to allow wings to generate enough lift for aerodynamic flight. [[Jet engine]]s don't work for want of oxygen, but other propulsion methods work well. Performing a horizontal landing with a [[plane]] is also possible.<br />
<br />
=== Lifting off ===<br />
<br />
An ascent to Low Duna Orbit from the surface typically requires around 1500 to 2000&nbsp;m/s in Delta-V to reach a 42&nbsp;km altitude traveling at roughly 950&nbsp;m/s.<br />
<br />
The following table gives terminal velocities at different Duna altitudes, which also the velocities at which a ship should travel for a fuel-optimal ascent from Duna, given the game's model of atmospheric drag.<ref>http://forum.kerbalspaceprogram.com/showthread.php/6664-Mini-challenge-max-altitude-with-this-supplied-spacecraft?p=100912&viewfull=1#post100912</ref><br />
{| class="wikitable"<br />
|-<br />
! Altitude (m) !! Velocity (m/s)<br />
|-<br />
| 0 || {{sigfigs|{{VT|planet=Duna|alt=0}}|3}}<br />
|-<br />
| 1000 || {{sigfigs|{{VT|planet=Duna|alt=1000}}|3}}<br />
|-<br />
| 2000 || {{sigfigs|{{VT|planet=Duna|alt=2000}}|3}}<br />
|-<br />
| 3000 || {{sigfigs|{{VT|planet=Duna|alt=3000}}|3}}<br />
|-<br />
| 5000 || {{sigfigs|{{VT|planet=Duna|alt=5000}}|3}}<br />
|-<br />
| 8000 || {{sigfigs|{{VT|planet=Duna|alt=8000}}|3}}<br />
|-<br />
| 10000 || {{sigfigs|{{VT|planet=Duna|alt=10000}}|3}}<br />
|-<br />
| 13000 || {{sigfigs|{{VT|planet=Duna|alt=13000}}|3}}<br />
|-<br />
| 15000 || {{sigfigs|{{VT|planet=Duna|alt=15000}}|3}}<br />
|-<br />
| 20000 || {{sigfigs|{{VT|planet=Duna|alt=20000}}|3}}<br />
|}<br />
<br />
== Orbital Statistics ==<br />
The [[synchronous orbit]] of Duna is at an altitude of {{OrbitAltitude|b=Duna|f=k}} above Duna. The speed of the satellite is {{OrbitVelocity|b=Duna}} and it has an orbital period resonating with 1 Duna day (18.2 hours or 65517.859375 seconds). However, this is the same altitude at which Ike orbits, so unless a ship's orbit is perfectly precise, it will eventually be captured by Ike.<br />
<br />
For a [[w:semi-synchronous orbit|semi-synchronous orbit]] of ½ Duna day (9.1 hours or 32758.9295 seconds) an orbit of<br />
{{OrbitAltitude|b=Duna|f=k|pf=1/2}} above Duna is needed with a velocity of {{OrbitVelocity|b=Duna|pf=1/2}}.<br />
<br />
== Observation of Ike ==<br />
{{gif image|Ikes_libration.gif|thumb|An animation of an orbit viewed from Duna|width=304|float=left|additional css=margin-right:1em;margin-bottom:1em}}<br />
Ike's orbit keeps it directly above a short range of Dunar longitudes. The average Duna longitude that Ike tends to stay directly above (at the [[w:Zenith|Zenith]]) is 6 degrees east, but the eccentricity of Ike's orbit causes the exact longitude to oscillate between about 2 degrees and 10 degrees east and makes Ike appear to grow slightly larger and smaller to an observer on the surface of Duna. The latitude at which Ike is in the Zenith also oscillates between 0.2 degrees south and 0.2 degrees north due to Ike's orbital inclination, making Ike appear to rotate upwards and downwards as viewed from the surface, but due to the extremely small orbital inclination, this effect is nearly imperceptible. These phenomena together are known as [[w:libration|libration]]. The oscillation in Ike's position above the horizon allows areas from 88°W to 80°W and 92°E to 100°E on Duna to observe Ike rise and set at least partially across the horizon, as can any areas north of 89.8°N or south of 89.8°S.<br />
<br />
== Interplanetary Travel ==<br />
<br />
From altitude orbit around Duna, the delta-V needed to reach the orbits of other celestials is:<br />
<br />
{| class="wikitable"<br />
!Body<br />
!colspan="2"|Delta-V<br />
|-<br />
| [[Ike]]<br />
|colspan="2"| ~300&nbsp;m/s<br />
|-<br />
| [[Kerbin]]<br />
|colspan="2"| ~620&nbsp;m/s<br />
|-<br />
| [[Dres]]<br />
|colspan="2"| ~820&nbsp;m/s<br />
|-<br />
| [[Eve]]<br />
|colspan="2"| ~1080&nbsp;m/s<br />
|-<br />
| [[Jool]]<br />
|colspan="2"| ~1350&nbsp;m/s<br />
|-<br />
| [[Eeloo]]<br />
|colspan="2"| ~1580&nbsp;m/s<br />
|-<br />
<br />
| [[Moho]]<br />
|colspan="2"| ~2100&nbsp;m/s<br />
|-<br />
|}<br />
{{clear|left}}<br />
<br />
== Reference Frames ==<br />
{{:Duna/RefFrame}}<br />
<br />
== Gallery ==<br />
<gallery><br />
File:Parachute_Descent.png|Parachute descent down to Duna surface. <br />
File:ISA_over_Duna.png|ISA satellite in orbit over Duna being used to map the planet surface.<br />
File:DunaSurface.png|Duna's surface at Dawn.<br />
File:Duna_and_ike.jpg|Duna and Ike.<br />
File:Duna_map_800.gif|A topographic height map of Duna made with the ISA MapSat plugin<br />
File:DoonaMap.png|A color map of Duna<br />
File:North pole of Duna.jpg|A lander on the northern pole of Duna.<br />
File:Duna_Sunrise.png|Duna at [http://www.youtube.com/watch?v=7czFsEpe4Ww&feature=youtu.be sunrise]<br />
File:Duna-sinkhole.png|A rover at the edge of one of the "sinkholes"<br />
File:Thepoopscooperduna1.png|Bill, his capsule, a flag, and Ike are all in this picture<br />
File:TakeoffFromDunaV21.1.png|A small probe after takeoff, climbing into Dunar orbit..<br />
File:OrbitingDunaV21.1.png|A small probe orbiting Duna.<br />
File:Duna_Ike_Eclipse.png|Ike partially eclipsing Kerbol. Note the dimmer light and the solar panels not charging.<br />
File:Duna from ike.png| Duna seen from Ike<br />
File:DunaExplorer.png |Peter Kerman exploring the surface of Duna with a nice view on Kerbol, Ike and the lander.<br />
</gallery><br />
<br />
== Changes ==<br />
;{{Version|0.90|}}<br />
* Added biomes<br />
;{{Version|0.21|}}<br />
* Art Pass<br />
;{{Version|0.18|}}<br />
* Minor art pass<br />
;{{Version|0.17|}}<br />
* Initial Release<br />
<br />
== Trivia ==<br />
* According to former developer NovaSilisko, Duna's appearance was inspired by the theory that ice ages on Mars may have brought the ice caps much closer to its equator. <ref>[http://forum.kerbalspaceprogram.com/threads/96153-Duna-s-ice-caps-are-too-big?p=1465456&viewfull=1#post1465456 NovaSilisko's] answer in “Duna's ice caps are too big”.</ref><br />
* Duna's name may be either a reference to its desert landscape or a reference to the [[w:Frank Herbert|Frank Herbert]] novel ''[[w:Dune (novel)|Dune]]''.<br />
* The low-lying areas near Duna's equator make a shape resembling Europe.<br />
{{SpoilerBox<br />
|description=Anomalous features<br />
|content=<br />
[[File:Kerbal face.jpg|60px|right]]<br />
* On the surface of Duna, there is a large monument carved in the likeness of a [[List of easter eggs#Duna|Kerbal face]], alluding to the infamous "Face of Mars" discovered in the Cydonia Mensae region of Mars during the 1970's. <br />
* Buried deep under the surface, there is a small camera, similar to the design on the [[w:Curiosity (rover)|Curiosity]] rover.<br />
* One anomalous feature on Duna is a small, pyramid-like hill emitting an SSTV signal. When decrypted, it shows a diagram-like image of three figures standing next to the hill itself, implying that Duna was once inhabited or visited before.<br />
}}<br />
<br />
== Notes ==<br />
<references /><br />
<br />
{{Celestial Bodies}}<br />
[[Category:Celestials]]<br />
[[Category:Planets]]</div>Dannyhttps://wiki.kerbalspaceprogram.com/index.php?title=Duna&diff=57479Duna2015-02-09T03:32:29Z<p>Danny: /* Topography */</p>
<hr />
<div>{{Infobox/Body}}<br />
<br />
'''Duna''' is the fourth planet of the [[Kerbol System|Kerbol star system]] and [[w:Mars|Mars]] analog for Kerbal Space Program. It is mostly red with polar icecaps and has one natural satellite, the [[moon]] '''[[Ike]]'''. Ike's size and proximity tidally locks it and Duna to each other.<br />
<br />
With proper [[aerobraking]], a round trip from [[Kerbin]] to Duna's [[orbit]] and back requires roughly 1700&nbsp;m/s of [[Terminology#Physics|delta-v]], less than a round trip to any other planet. Duna is often the easiest planet to [[encounter]] because its orbital inclination is low.<br />
<br />
There is a [[tutorial]] about [[Tutorial:How to get to Duna|Traveling to Duna and Back]].<br />
<br />
== In-game Description ==<br />
<br />
{{Quote<br />
<br />
|Also known as the red dot that you can see if you squint at it really hard, Duna has long been a wonder to Kerbalkind. <br><br> The planet has been held in much awe due to its striking red color and stark contrast to the color green.<br />
<br />
|Kerbal Astronomical Society}}<br />
<br />
== Topography ==<br />
[[File:Duna Topo ISA 3200x1600 compressed.png|thumb|left|A topographic map of Duna made with the ISA MapSat plugin]]<br />
Duna's terrain ranges in altitude from 124 to 8264 meters. Its mountain ranges are a peril to landing [[craft]], due to their steepness and the limited [[aerobraking]] that is possible in Duna's tenuous [[atmosphere]] at such altitudes.<br />
<br />
Duna has several craters. They appear quite eroded, presumably by the wind.<br />
<br />
Several [[w:Lunar maria|maria]] (large regions of dark soil) are at exactly 0 meters altitude {{deprecated}}. Their low altitude allows for more aerobraking, and the flatness of the terrain makes them easy but boring landing locations. These may have been lakes when the planet may have had liquid on its surface in the past.<br />
<br />
Duna's surface contains [[List of easter eggs#Duna|anomalous features]].<br />
<br />
== Biomes==<br />
Duna has 5 [[biome]]s.<br />
<br />
=== Biome list ===<br />
{{Biome list|<br />
* Poles<br />
* Highlands<br />
* Midlands<br />
* Lowlands<br />
* Craters}}<br />
<br />
== Atmosphere ==<br />
[[File:Atmosphere kerbin duna.png|thumb|left|A comparison of the atmospheres of Duna and Kerbin]]<br />
[[File:Duna north pole.png|thumb|left|Duna's north pole]]<br />
<br />
Duna's [[atmosphere]] begins at 41,446 m. It is only 20% as dense as [[Kerbin|Kerbin's]] at sea level altitude and is even less dense relative to Kerbin at higher altitudes. At Duna's highest peak, atmospheric density is only 21% of that at sea level. For comparison, on Kerbin, the atmosphere at the highest peaks is 45% as thick as at sea level. This low density will cause [[parachute]]s to semi-deploy much lower, just over 10&nbsp;km for the [[Mk25 Parachute]], and just under 9&nbsp;km for all the other parachutes.<br />
<br />
In comparison is the atmosphere the thinnest of all bodies with an atmosphere. Even [[Jool]]'s moon [[Laythe]] has a more dense and higher atmosphere. The atmosphere appears to have a reddish or brownish tone itself. On the poles the illuminated atmosphere is coloured although the surface is white.<br />
<br />
=== Landing ===<br />
[[Aerobraking]] can save fuel by reducing orbital and surface velocity greatly. An aerobraking maneuver should maximize time spent in the atmosphere by entering at a shallow angle and aiming for a landing location in a low-lying area. One estimate for a good aerobraking height is 13,000 meters, which will then allow a relatively low delta-V burn at the apoapsis to create a stable orbit safely within Ike's reign of chaos.<br />
<br />
Like all atmospheres in the game, Duna's atmosphere fades exponentially with increasing altitude (with a scale height of 3000 m). In general, the atmospheric pressure on Duna at an altitude expressed in meters is:<ref>A [[LV-N Atomic Rocket Motor]] has a specific impulse of 220 in 1 atm, 800 in vacuum, and the following at various Duna altitudes:<br />
{| class="wikitable"<br />
! altitude (m)<br />
| 2 || 100 || 300 || 500 || 1460 || 2420 || 3000 || 4272 || 5000 || 10000<br />
|-<br />
! specific impulse<br />
| 684.1 || 687.8 || 695.1 || 701.8 || 728.7 || 748.2 || 757.3 || 772.1 || 778.1 || 795.9<br />
|}</ref><br />
<br />
: <math>p_d = 0.2 \text{atm} \ e^\frac{-altitude}{3000 \text{m}}</math><br />
<br />
Although parachutes will deploy on Duna, the atmosphere is so thin that they are usually unable to slow a craft to a safe landing velocity and must be assisted with engines.<br />
<br />
[[File:Duna colony.png|thumb|A nine Kerbal colony on Duna]]<br />
<br />
=== Flying ===<br />
<br />
Below 5&nbsp;km Duna's atmosphere is thick enough to allow wings to generate enough lift for aerodynamic flight. [[Jet engine]]s don't work for want of oxygen, but other propulsion methods work well. Performing a horizontal landing with a [[plane]] is also possible.<br />
<br />
=== Lifting off ===<br />
<br />
An ascent to Low Duna Orbit from the surface typically requires around 1500 to 2000&nbsp;m/s in Delta-V to reach a 42&nbsp;km altitude traveling at roughly 950&nbsp;m/s.<br />
<br />
The following table gives terminal velocities at different Duna altitudes, which also the velocities at which a ship should travel for a fuel-optimal ascent from Duna, given the game's model of atmospheric drag.<ref>http://forum.kerbalspaceprogram.com/showthread.php/6664-Mini-challenge-max-altitude-with-this-supplied-spacecraft?p=100912&viewfull=1#post100912</ref><br />
{| class="wikitable"<br />
|-<br />
! Altitude (m) !! Velocity (m/s)<br />
|-<br />
| 0 || {{sigfigs|{{VT|planet=Duna|alt=0}}|3}}<br />
|-<br />
| 1000 || {{sigfigs|{{VT|planet=Duna|alt=1000}}|3}}<br />
|-<br />
| 2000 || {{sigfigs|{{VT|planet=Duna|alt=2000}}|3}}<br />
|-<br />
| 3000 || {{sigfigs|{{VT|planet=Duna|alt=3000}}|3}}<br />
|-<br />
| 5000 || {{sigfigs|{{VT|planet=Duna|alt=5000}}|3}}<br />
|-<br />
| 8000 || {{sigfigs|{{VT|planet=Duna|alt=8000}}|3}}<br />
|-<br />
| 10000 || {{sigfigs|{{VT|planet=Duna|alt=10000}}|3}}<br />
|-<br />
| 13000 || {{sigfigs|{{VT|planet=Duna|alt=13000}}|3}}<br />
|-<br />
| 15000 || {{sigfigs|{{VT|planet=Duna|alt=15000}}|3}}<br />
|-<br />
| 20000 || {{sigfigs|{{VT|planet=Duna|alt=20000}}|3}}<br />
|}<br />
<br />
== Orbital Statistics ==<br />
The [[synchronous orbit]] of Duna is at an altitude of {{OrbitAltitude|b=Duna|f=k}} above Duna. The speed of the satellite is {{OrbitVelocity|b=Duna}} and it has an orbital period resonating with 1 Duna day (18.2 hours or 65517.859375 seconds). However, this is the same altitude at which Ike orbits, so unless a ship's orbit is perfectly precise, it will eventually be captured by Ike.<br />
<br />
For a [[w:semi-synchronous orbit|semi-synchronous orbit]] of ½ Duna day (9.1 hours or 32758.9295 seconds) an orbit of<br />
{{OrbitAltitude|b=Duna|f=k|pf=1/2}} above Duna is needed with a velocity of {{OrbitVelocity|b=Duna|pf=1/2}}.<br />
<br />
== Observation of Ike ==<br />
{{gif image|Ikes_libration.gif|thumb|An animation of an orbit viewed from Duna|width=304|float=left|additional css=margin-right:1em;margin-bottom:1em}}<br />
Ike's orbit keeps it directly above a short range of Dunar longitudes. The average Duna longitude that Ike tends to stay directly above (at the [[w:Zenith|Zenith]]) is 6 degrees east, but the eccentricity of Ike's orbit causes the exact longitude to oscillate between about 2 degrees and 10 degrees east and makes Ike appear to grow slightly larger and smaller to an observer on the surface of Duna. The latitude at which Ike is in the Zenith also oscillates between 0.2 degrees south and 0.2 degrees north due to Ike's orbital inclination, making Ike appear to rotate upwards and downwards as viewed from the surface, but due to the extremely small orbital inclination, this effect is nearly imperceptible. These phenomena together are known as [[w:libration|libration]]. The oscillation in Ike's position above the horizon allows areas from 88°W to 80°W and 92°E to 100°E on Duna to observe Ike rise and set at least partially across the horizon, as can any areas north of 89.8°N or south of 89.8°S.<br />
<br />
== Interplanetary Travel ==<br />
<br />
From altitude orbit around Duna, the delta-V needed to reach the orbits of other celestials is:<br />
<br />
{| class="wikitable"<br />
!Body<br />
!colspan="2"|Delta-V<br />
|-<br />
| [[Ike]]<br />
|colspan="2"| ~300&nbsp;m/s<br />
|-<br />
| [[Kerbin]]<br />
|colspan="2"| ~620&nbsp;m/s<br />
|-<br />
| [[Dres]]<br />
|colspan="2"| ~820&nbsp;m/s<br />
|-<br />
| [[Eve]]<br />
|colspan="2"| ~1080&nbsp;m/s<br />
|-<br />
| [[Jool]]<br />
|colspan="2"| ~1350&nbsp;m/s<br />
|-<br />
| [[Eeloo]]<br />
|colspan="2"| ~1580&nbsp;m/s<br />
|-<br />
<br />
| [[Moho]]<br />
|colspan="2"| ~2100&nbsp;m/s<br />
|-<br />
|}<br />
{{clear|left}}<br />
<br />
== Reference Frames ==<br />
{{:Duna/RefFrame}}<br />
<br />
== Gallery ==<br />
<gallery><br />
File:Parachute_Descent.png|Parachute descent down to Duna surface. <br />
File:ISA_over_Duna.png|ISA satellite in orbit over Duna being used to map the planet surface.<br />
File:DunaSurface.png|Duna's surface at Dawn.<br />
File:Duna_and_ike.jpg|Duna and Ike.<br />
File:Duna_map_800.gif|A topographic height map of Duna made with the ISA MapSat plugin<br />
File:DoonaMap.png|A color map of Duna<br />
File:North pole of Duna.jpg|A lander on the northern pole of Duna.<br />
File:Duna_Sunrise.png|Duna at [http://www.youtube.com/watch?v=7czFsEpe4Ww&feature=youtu.be sunrise]<br />
File:Duna-sinkhole.png|A rover at the edge of one of the "sinkholes"<br />
File:Thepoopscooperduna1.png|Bill, his capsule, a flag, and Ike are all in this picture<br />
File:TakeoffFromDunaV21.1.png|A small probe after takeoff, climbing into Dunar orbit..<br />
File:OrbitingDunaV21.1.png|A small probe orbiting Duna.<br />
File:Duna_Ike_Eclipse.png|Ike partially eclipsing Kerbol. Note the dimmer light and the solar panels not charging.<br />
File:Duna from ike.png| Duna seen from Ike<br />
File:DunaExplorer.png |Peter Kerman exploring the surface of Duna with a nice view on Kerbol, Ike and the lander.<br />
</gallery><br />
<br />
== Changes ==<br />
;{{Version|0.90|}}<br />
* Added biomes<br />
;{{Version|0.21|}}<br />
* Art Pass<br />
;{{Version|0.18|}}<br />
* Minor art pass<br />
;{{Version|0.17|}}<br />
* Initial Release<br />
<br />
== Trivia ==<br />
* According to former developer NovaSilisko, Duna's appearance was inspired by the theory that ice ages on Mars may have brought the ice caps much closer to its equator. <ref>[http://forum.kerbalspaceprogram.com/threads/96153-Duna-s-ice-caps-are-too-big?p=1465456&viewfull=1#post1465456 NovaSilisko's] answer in “Duna's ice caps are too big”.</ref><br />
* Duna's name may be either a reference to its desert landscape or a reference to the [[w:Frank Herbert|Frank Herbert]] novel ''[[w:Dune (novel)|Dune]]''.<br />
* The low-lying areas near Duna's equator make a shape resembling Europe.<br />
{{SpoilerBox<br />
|description=Anomalous features<br />
|content=<br />
[[File:Kerbal face.jpg|60px|right]]<br />
* On the surface of Duna, there is a large monument carved in the likeness of a [[List of easter eggs#Duna|Kerbal face]], alluding to the infamous "Face of Mars" discovered in the Cydonia Mensae region of Mars during the 1970's. <br />
* Buried deep under the surface, there is a small camera, similar to the design on the [[w:Curiosity (rover)|Curiosity]] rover.<br />
* One anomalous feature on Duna is a small, pyramid-like hill emitting an SSTV signal. When decrypted, it shows a diagram-like image of three figures standing next to the hill itself, implying that Duna was once inhabited or visited before.<br />
}}<br />
<br />
== Notes ==<br />
<references /><br />
<br />
{{Celestial Bodies}}<br />
[[Category:Celestials]]<br />
[[Category:Planets]]</div>Dannyhttps://wiki.kerbalspaceprogram.com/index.php?title=Kerbal_Space_Center&diff=57478Kerbal Space Center2015-02-09T03:19:41Z<p>Danny: /* Launch pad */</p>
<hr />
<div>{{:Kerbal Space Center/Box}}<br />
[[File:KSC at night.png|thumb|The Kerbal Space Center illuminated at night]]<br />
<br />
The '''Kerbal Space Center''' (abbr. '''KSC'''), located on [[Kerbin]], is the only current location that missions can be launched from. Featuring a number of buildings and structures on an approximately 25&nbsp;km² large plateau, it acts as a central hub granting access to all parts of the game. All buildings, except for the runway, are placed on hexagonal sections (mostly regular, except the one for the tracking station which is a truncated triangle).<br />
<br />
Since 0.25, depending on the [[Game Difficulty]] settings, the buildings of KSC are destructible, taking damage from impacts.<br />
<br />
Since 0.90, there are multiple levels to each building in the [[Career]] mode, with the starting buildings having significant restrictions compared to previously. Upgrading all of these facilities costs 9.8 million [[funds]] (modulo the difficulty setting), and is likely to take the dominant portion of spending in the early game.<br />
<br />
== Always functional structures ==<br />
<br />
=== Vehicle Assembly Building ===<br />
The [[Vehicle Assembly Building]] (or VAB for short) is a large construction facility at KSC, where rockets and other vertically launched spacecraft can be designed. Craft designed in the VAB can only be launched from the Launch Pad, though it is possible to import vessels between the VAB and SPH.<br />
[[File:VABwLP.jpg|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Supported part count !! [[Action group]]s available<br />
|-<br />
| 1 || Start || 30 || None<br />
|-<br />
| 2 || 210 000 || 255 || Basic<sup>[''qualify'']</sup><br />
|-<br />
| 3 || 1 300 000 || Unlimited || Custom<br />
|}<br />
{{clear}}<br />
=== Launch pad ===<br />
Craft designed in the VAB will be launched from the [[launch pad]]. This launch platform allows vertical launches, or may serve as a starting point for rovers. It is too small to be useful for crafts that require take off or landing runs.<br />
<br />
[[File:LP22.png|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Max vessel height (m) !! Max vessel width (m) !! Max vessel mass (t)<br />
|-<br />
| 1 || Start || 20.0 || 21.2 || 18<br />
|-<br />
| 2 || 52 000 || 36.0 || 39.6 || 140<br />
|-<br />
| 3 || 322 000 || Unlimited || Unlimited || Unlimited<br />
|}<br />
{{clear}}<br />
<br />
=== Space Plane Hangar ===<br />
The [[Space Plane Hangar]] (or SPH for short) is a facility similar to the VAB that allows construction of aircraft and spacecraft in a horizontal environment which can then be launched from a conventional runway.<br />
[[File:SPH.jpg|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Supported part count !! [[Action group]]s available<br />
|-<br />
| 1 || Start || 30 || None<br />
|-<br />
| 2 || 202 000 || 255 || Basic<sup>[''qualify'']</sup><br />
|-<br />
| 3 || 1 258 000 || Unlimited || Custom<br />
|}<br />
{{clear}}<br />
=== Runway ===<br />
Vessels designed in the Space Plane Hangar can only be launched from the [[runway]]. It can also be used for landing. At the moment there is only one runway (09/27) in service with a length of 2526&nbsp;m going from east to west and a width of 70&nbsp;m. There is also a runway on an [[Old Airfield|island]] to the southeast, which is available for landing but not launching. By default, craft designed in the SPH face a 90° heading (facing east) and start from the west end.<br />
[[File:Runway.jpg|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Max vessel length (m) !! Max vessel width/height (m) !! Max vessel mass (t)<br />
|-<br />
| 1 || Start || 20 || 15 || 18<br />
|-<br />
| 2 || 90 000 || 36 || 28 || 140<br />
|-<br />
| 3 || 560 000 || Unlimited || Unlimited || Unlimited<br />
|}<br />
{{clear}}<br />
=== Tracking Station ===<br />
The [[Tracking Station]] allows access, observation and management of all missions currently active, including splashed-down or landed ships. Note that this does not include crashed or otherwise ended missions. Any Kerbals, craft or [[debris]] safely on Kerbin's surface can be recovered here. Debris can be tracked and deleted here. [[Celestial body|Celestial bodies]] can also be observed at the Tracking Station.<br />
[[File:TC.jpg|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Functions<br />
|-<br />
| 1 || Start || Orbits visible in map<br />
|-<br />
| 2 || 140 000 || Patched Conics visible in map<br />
|-<br />
| 3 || 875 000 || Patched Conics visible in map and unowned object tracking<br />
|}<br />
{{clear}}<br />
=== Astronaut Complex ===<br />
The [[Astronaut Complex]] allows hiring of astronauts to join the crew of future missions.<br />
[[File:ACwFP.jpg|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Capacity !! Kerbals can EVA and plant flags<br />
|-<br />
| 1 || Start || 5 Kerbals || Unavailable<br />
|-<br />
| 2 || 70 000 || 12 Kerbals || Available<br />
|-<br />
| 3 || 437 000 || Unlimited || Available<br />
|}<br />
<div style="text-align: left; direction: ltr; margin-left: 15em;"> <br />
==== Flag Pole ====<br />
The [[Flag Pole]] is located in front of the Astronaut Complex and can be used to select a default mission flag. It used to be located south-west of the [[VAB]], but was moved in {{Version|0.21}}.<br />
</div><br />
{{clear}}<br />
== Career/Science Mode structures ==<br />
=== Research and Development ===<br />
The [[Research and Development]] building allows players to unlock spacecraft parts in [[career]] and [[science mode]] by researching nodes on the [[tech tree]].<br />
[[File:R&Dout.jpg|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Science limit !! Surface samples and resource transfer<!-- resource like liquid fuel or like science results? --><br />
|-<br />
| 1 || Start || 100 || Unavailable<br />
|-<br />
| 2 || 510 000 || 500 || Available<br />
|-<br />
| 3 || 3 180 000 || Unlimited || Available<br />
|}<br />
{{clear}}<br />
=== Mission Control ===<br />
[[Mission Control]] is a small building located north of the VAB and east of the SPH. It is used for getting [[contracts]].<br />
[[File:MC Front.png|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Active contracts !! Flight planning<br />
|-<br />
| 1 || Start || 2 || Unavailable<br />
|-<br />
| 2 || 32 000 || 7 || Available<br />
|-<br />
| 3 || 200 000 || Unlimited || Available<br />
|}<br />
{{clear}}<br />
=== Administration Facility ===<br />
The [[Administration Facility]] is a small building in face of the Astronaut Complex. It is can be used for getting/using [[strategies]].<br />
[[File:Administration Facility.jpg|left|frameless]]<br />
{|class="wikitable"<br />
|-<br />
! Level !! Cost !! Active strategies || Commitment<br />
|-<br />
| 1 || Start || 1 || 25.0%<br />
|-<br />
| 2 || 50 000 || 3 || 60.0%<br />
|-<br />
| 3 || 312 000 || 5 || 100.0%<br />
|}<br />
{{clear}}<br />
== Non-functional Structures ==<br />
[[File:LP1.png|thumb|The illuminated water tower at night]]<br />
=== Coolant Tanks ===<br />
A big globular Coolant Tank with a climbable ladder as well as three smaller Coolant Tanks can be found south-west of the Launchpad.<br />
=== Water Tower ===<br />
Located south-east of the Launchpad, the Water Tower is about as tall as 1/3 of the [[VAB]]. It is possibly part of an unseen Sound Suppression Water System similar to the one at Launch Complex 39 in real life.<br />
<br />
=== Flag Pole ===<br />
A second flag pole can be found on the northwest of the Launch Pad.<br />
{{clear}}<br />
<span id="LoB"></span><br />
== Location of the functional buildings in the Space Center ==<br />
[[File:KSP ksc.jpg|384px|left|frameless]]<br />
{|<br />
|<br />
# [[#Vehicle Assembly Building|Vehicle Assembly Building]]<br />
# [[#Launch pad|Launch pad]]<br />
# [[#Space Plane Hangar|Space Plane Hangar]]<br />
# [[#Runway|Runway]]<br />
# [[#Tracking Station|Tracking Station]]<br />
# [[#Astronaut Complex|Astronaut Complex]]<br />
# [[#Flag Pole|Flag Pole]]<br />
# [[#Research and Development|Research and Development]]<br />
# [[#Administration Facility|Administration Facility]]<br />
# [[#Mission Control|Mission Control]]<br />
|}<br />
{{clear}}<br />
== Location of the KSC on Kerbin, From Orbit ==<br />
[[File:KSCorbit.jpg|187px|left|frameless]]<br />
The KSC is on a roughly square-shaped, sandy peninsula on the east coast of an [[w:Africa|Africa]]-shaped continent. To assist in spotting the KSC from orbit, please refer to this handy map (it's marked with the red arrow):<br />
{{clear}}<br />
== See also ==<br />
* [[Inland Kerbal Space Center]]<br />
* [[Old Airfield]]<br />
<br />
== Trivia ==<br />
*The KSC's name could be a reference to the NASA space center, the [[w:Kennedy Space Center|Kennedy Space Center]] (KSC).<br />
[[Category:Locations]]<br />
[[Category:Spaceport]]</div>Dannyhttps://wiki.kerbalspaceprogram.com/index.php?title=Electric_light&diff=57476Electric light2015-02-09T03:05:20Z<p>Danny: </p>
<hr />
<div>[[File:Colored lights.png|thumb|A Mun lander employing coloured electric lights]]<br />
{{stub}}<br />
{{About|the parts which generate light|properties about light in general|light}}<br />
A '''light''' is a part that uses [[electricity]] or electric charge to shine a light. They can be used to provide visibility while landing at night or in a shaded area, and also to illuminate the craft itself. Electric lights are also useful for illuminating a rendez-vous target, such as a space station, if the vehicle is expecting to mate with a docking port that is in shade. For tidally locked moons like [[Mun]], [[Vall]] or [[Ike]], overnight landing missions are recommended to have any lights accompanied by large [[battery]] banks, or an [[RTG]], as one night can be very long.<br />
<br />
Currently, there are three major light sources. The [[Illuminator Mk1]] and [[Illuminator Mk2]] are the only dedicated light sources available. The [[Small Gear Bay]] also holds a light source which can be toggled. The [[Telus-LV Bay Mobility Enhancer]] also has a small electric light, though its light is too weak to illuminate anything other than its self, and can't be switched off. <br />
<br />
With version [[0.23.5]], all dedicated light sources can have their colors changed in the [[VAB]] and [[SPH]] using [[tweakable]]s. It is possible to change all three RGB color channels independently to produce nearly any colour of light.<br />
<br />
== Available lights ==<br />
{{Stats Table Lights}}<br />
<br />
[[Category:Parts]]<br />
[[Category:Lights| ]]</div>Dannyhttps://wiki.kerbalspaceprogram.com/index.php?title=PB-X150_Xenon_Container&diff=57475PB-X150 Xenon Container2015-02-09T02:59:21Z<p>Danny: /* Usage */</p>
<hr />
<div>{{:PB-X150 Xenon Container/Box}}<br />
The '''PB-X150 Xenon Container''' is a small fuel tank filled with [[xenon gas]].<br />
<br />
== Usage ==<br />
The container's only use is to provide xenon gas to the [[PB-ION Electric Propulsion System]], since it is the only part that can utilize xenon. The container stores 700 units of xenon with a mass of 0.1&nbsp;kg per unit of xenon. There is also a radial tank with only 400 units of xenon, the [[PB-X50R Xenon Container]].<br />
<br />
== Product description ==<br />
{{Quote<br />
|Although most of the KSC staff can't pronounce "Xenon", when told how to say it correctly, they all agree it sounds super-cool - and everything possible should be done so it can be used as a fuel.<br />
}}<br />
<br />
== Changes ==<br />
;{{Version|0.18|}}<br />
* Initial Release<br />
<br />
{{Parts}}</div>Danny