Difference between revisions of "Duna"
(Reverting french) |
|||
Line 14: | Line 14: | ||
|radius=320000 | |radius=320000 | ||
|mass=4.51548115036107e21 | |mass=4.51548115036107e21 | ||
− | |||
|gravityv=1.1 | |gravityv=1.1 | ||
|escv=1372.4 | |escv=1372.4 | ||
Line 31: | Line 30: | ||
}} | }} | ||
− | '''Duna''' | + | '''Duna''' is the fourth planet of the [[Kerbol]] star system. It is the Mars analog for Kerbal Space Program and is mostly red with polar icecaps. It has one natural satellite, the [[moon]] '''[[Ike]]'''. Due to Ike's size and proximity, Ike and Duna are tidally locked to each other. |
− | == | + | == Topography == |
{| | {| | ||
| | | | ||
[[File:Duna Topo ISA 3200x1600 compressed.png|thumb|right|A topographic map of Duna made with the ISA MapSat plugin]] | [[File:Duna Topo ISA 3200x1600 compressed.png|thumb|right|A topographic map of Duna made with the ISA MapSat plugin]] | ||
− | Duna | + | Duna is a iron-rich planet which has greatly varying land altitude, the consequence of which is very difficult judgment of a safe landing position. Its mountainous ranges are a peril to landing craft, especially considering the thin atmosphere, where very little aerobraking can be done safely. It is important to slow one's ship down before coming into the atmosphere, to ensure a safe descent. |
+ | There are several [[w:lunar maria|maria]] (large regions of dark soil) at exactly 0 meters altitude. These are excellent landing locations due to the their flatness and their low altitude, which allows for more aerobraking. | ||
− | + | Duna's poles are very expansive and are the result of a thin atmosphere. The central regions make a shape resembling Europe. | |
− | + | Duna's surface contains [[list of easter eggs#Duna|anomolous features]], including a rock face similar to the one seen in [[w:Cydonia (region of Mars)#"Face on Mars"|early satellite images of Mars]]. | |
− | |||
− | |||
|} | |} | ||
− | == | + | == Atmosphere == |
{| | {| | ||
| | | | ||
[[File:Atmosphere_kerbin_duna.png|thumb|right|A comparison of the atmospheres of Duna and Kerbin]] | [[File:Atmosphere_kerbin_duna.png|thumb|right|A comparison of the atmospheres of Duna and Kerbin]] | ||
− | + | Duna's [[atmosphere]] begins at 41,446 m. It is only 20% as dense as [[Kerbin|Kerbin's]] at altitude 0 and is even less dense (relative to Kerbin) at higher altitudes. | |
− | + | 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 Engine|nuclear engine]] has a specific impulse of 220 in 1 atm, 800 in vacuum, and the following at various Duna altitudes: | |
− | |||
{| | {| | ||
| altitude (m) || 2 || 100 || 300 || 500 || 1460 || 2420 || 3000 || 4272 || 5000 || 10000 | | altitude (m) || 2 || 100 || 300 || 500 || 1460 || 2420 || 3000 || 4272 || 5000 || 10000 | ||
|- | |- | ||
− | | | + | | specific impulse || 684.1 || 687.8 || 695.1 || 701.8 || 728.7 || 748.2 || 757.3 || 772.1 || 778.1 || 795.9 |
|}</ref> | |}</ref> | ||
: <math>p_d = 0.2\ e^{-altitude/3000}</math> | : <math>p_d = 0.2\ e^{-altitude/3000}</math> | ||
− | + | Parachutes work at lower efficiency than on Kerbin, making powered descent necessary when landing from orbit (unless your craft is a glider or just a pod with a parachute). | |
− | + | The following table gives terminal velocities at different Duna altitudes. These are 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> | |
{| class="wikitable" | {| class="wikitable" | ||
|- | |- | ||
− | ! Altitude (m) !! | + | ! Altitude (m) !! Velocity (m/s) |
|- | |- | ||
| 0 || {{sigfigs|{{VT|planet=Duna|alt=0}}|3}} | | 0 || {{sigfigs|{{VT|planet=Duna|alt=0}}|3}} | ||
Line 93: | Line 90: | ||
|} | |} | ||
− | == | + | == Orbital Statistics == |
− | + | The [[w:geosynchronous_orbit|geosynchronous orbit]] of Duna is at an altitude of | |
− | {{OrbitAltitude | period_s=65517.859375 | mass_kg=4.51548115036107e21 | radius_km=320 }} | + | {{OrbitAltitude | period_s=65517.859375 | mass_kg=4.51548115036107e21 | radius_km=320 }} above Duna. The speed of the satellite is |
− | {{OrbitVelocity | period_s=65517.859375 | mass_kg=4.51548115036107e21 | radius_km=320 }} | + | {{OrbitVelocity | period_s=65517.859375 | mass_kg=4.51548115036107e21 | radius_km=320 }} and it has an orbital period resonating with 1 Duna day (18.2 hours or 65517.859375 seconds). However, this orbit is not possible since it intersects with Ike's SOI. |
− | |||
− | + | For a [[w:semi-synchronous_orbit|semi-synchronous orbit]] of ½ Duna day (9.025 hours or 32490 seconds) an orbit of | |
− | {{OrbitAltitude | period_s=32758.9296875 | mass_kg=4.51548115036107e21 | radius_km=320 }} | + | {{OrbitAltitude | period_s=32758.9296875 | mass_kg=4.51548115036107e21 | radius_km=320 }} above Duna is needed with a velocity of |
{{OrbitVelocity | period_s=32758.9296875 | mass_kg=4.51548115036107e21 | radius_km=320 }}. | {{OrbitVelocity | period_s=32758.9296875 | mass_kg=4.51548115036107e21 | radius_km=320 }}. | ||
− | == | + | == Reference Frames == |
{| class="wikitable" | {| class="wikitable" | ||
|- | |- | ||
| Warp || 5x, 10x || 50x || 100x || 1000x || 10,000x || 100,000x | | Warp || 5x, 10x || 50x || 100x || 1000x || 10,000x || 100,000x | ||
|- | |- | ||
− | | Altitude | + | | Minimum Altitude || above atmosphere || 60 km || 100 km || 300 km || 600 km || 800 km |
|} | |} | ||
− | == | + | == Gallery == |
<gallery> | <gallery> | ||
− | File:ISA_over_Duna.png| | + | File:ISA_over_Duna.png|ISA satellite in orbit over Duna being used to map the planet surface. |
− | File:DunaSurface.png| | + | File:DunaSurface.png|Duna's surface at Dawn. |
− | File:Duna_projection.png| | + | File:Duna_projection.png|A false color Mercator projection of Duna's surface using MapSat. |
− | File:Duna_and_ike.jpg|Duna | + | File:Duna_and_ike.jpg|Duna and Ike. |
− | File:Duna_map_800.gif| | + | File:Duna_map_800.gif|A topografic height map of Duna made with the ISA MapSat plugin |
− | File:DoonaMap.png| | + | File:DoonaMap.png|A color map of Duna |
</gallery> | </gallery> | ||
− | == | + | == Changes == |
;{{Version|0.17|}} | ;{{Version|0.17|}} | ||
− | * | + | * Initial Release |
== Notes == | == Notes == |
Revision as of 13:38, 26 November 2012
Duna is the fourth planet of the Kerbol star system. It is the Mars analog for Kerbal Space Program and is mostly red with polar icecaps. It has one natural satellite, the moon Ike. Due to Ike's size and proximity, Ike and Duna are tidally locked to each other.
Contents
Topography
Duna is a iron-rich planet which has greatly varying land altitude, the consequence of which is very difficult judgment of a safe landing position. Its mountainous ranges are a peril to landing craft, especially considering the thin atmosphere, where very little aerobraking can be done safely. It is important to slow one's ship down before coming into the atmosphere, to ensure a safe descent. There are several maria (large regions of dark soil) at exactly 0 meters altitude. These are excellent landing locations due to the their flatness and their low altitude, which allows for more aerobraking. Duna's poles are very expansive and are the result of a thin atmosphere. The central regions make a shape resembling Europe. Duna's surface contains anomolous features, including a rock face similar to the one seen in early satellite images of Mars. |
Atmosphere
Duna's atmosphere begins at 41,446 m. It is only 20% as dense as Kerbin's at altitude 0 and is even less dense (relative to Kerbin) at higher altitudes. 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:[1] Parachutes work at lower efficiency than on Kerbin, making powered descent necessary when landing from orbit (unless your craft is a glider or just a pod with a parachute). The following table gives terminal velocities at different Duna altitudes. These are also the velocities at which a ship should travel for a fuel-optimal ascent from Duna, given the game's model of atmospheric drag.[2]
|
Orbital Statistics
The geosynchronous orbit of Duna is at an altitude of 0.00 m above Duna. The speed of the satellite is 0.00 m/s and it has an orbital period resonating with 1 Duna day (18.2 hours or 65517.859375 seconds). However, this orbit is not possible since it intersects with Ike's SOI.
For a semi-synchronous orbit of ½ Duna day (9.025 hours or 32490 seconds) an orbit of 0.00 m above Duna is needed with a velocity of 0.00 m/s.
Reference Frames
Warp | 5x, 10x | 50x | 100x | 1000x | 10,000x | 100,000x |
Minimum Altitude | above atmosphere | 60 km | 100 km | 300 km | 600 km | 800 km |
Gallery
- Duna projection.png
A false color Mercator projection of Duna's surface using MapSat.
Changes
- Initial Release
Notes
- ↑ A nuclear engine has a specific impulse of 220 in 1 atm, 800 in vacuum, and the following at various Duna altitudes:
altitude (m) 2 100 300 500 1460 2420 3000 4272 5000 10000 specific impulse 684.1 687.8 695.1 701.8 728.7 748.2 757.3 772.1 778.1 795.9 - ↑ http://forum.kerbalspaceprogram.com/showthread.php/6664-Mini-challenge-max-altitude-with-this-supplied-spacecraft?p=100912&viewfull=1#post100912