Difference between revisions of "IX-6315 "Dawn" Electric Propulsion System"
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(*Slightly better phrasing, section's numbers are not obsolete, though the improving VAB UI reduces its utility.)
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=== Electrical consumption ===
=== Electrical consumption ===
The part.cfg lists the electrical consumption as 1.8 E which is the electricity consumed for 0.1 xenon. propel 1 xenon an electricity of 18 E is required. As seen ingame, the fuel flow is 0.0485 kg/s or 0.4849 xenon/s. The electricity consumption is 8.7285 E/s.<ref>Answer in the forum to [http://forum.kerbalspaceprogram.com/showthread.php/26354-Ion-Engine-consumes-more-energy-than-it-should?p=321868&viewfull=1#post321868 Ion Engine consumes more energy than it should].</ref> As the I<sub>sp</sub> given in seconds needs to be multiplied with a slightly higher acceleration (9.82 m/s²) than g<sub>0</sub> (= 9.81 m/s²) the actual I<sub>sp</sub> in m/s is higher and therefore the xenon and electrical consumption is lower.<ref>In [[:File:10X Xenon.png]] 10 PB-Ion engines are running at full power and consuming a lower value that 10× the theoretical value.</ref>
The part.cfg lists the electrical consumption as 1.8 E which is the electricity consumed for 0.1 xenon.
== Description ==
== Description ==
Revision as of 07:41, 1 June 2014
|IX-6315 "Dawn" Electric Propulsion System|
| Ion engine by |
Ionic Symphonic Protonic Electronics
|Max. Temp.||2000 K|
|Impact Tolerance||7 m/s|
|Unlock cost||16 800|
|Maximum thrust||(1 atm)||0.05 kN|
|Isp||(1 atm)||100 s|
|Fuel consumption|| 0.486 /s
|Thrust vectoring||× No|
|Electricity required||367.098 ⚡/s|
|On the surface||× No|
|In the ocean||× No|
|On the launchpad||× No|
|In the atmosphere||× No|
|Sub orbital||✓ Yes|
|In an orbit||✓ Yes|
|On an escape||✓ Yes|
|Test by staging||✓ Yes|
|Manually testable||✓ Yes|
The PB-ION Electric Propulsion System is a tiny-sized engine which runs on electricity and xenon gas propellant. It's modeled after the real-world Hall effect thruster. Although it is a propulsion system, it can be found in the utility tab of the VAB and SPH.
This engine has a phenomenal fuel efficiency (4200 s Isp), but very low thrust and requires an immense amount of electricity to operate. Xenon gas is provided by xenon containers like the PB-X150 Xenon Container. Electricity can be obtained using solar panels and radioisotope batteries. The amount of electricity needed to keep one ion engine running at full thrust is roughly equivalent to half the output of one Gigantor XL Solar Array (however one array will not power 2 engines), 12 PB-NUK Radioisotope Thermoelectric Generators, or 7 OX-STAT Photovoltaic Panels.
The ion engine is good for fine tuning of orbits. It is also a popular propulsion method for planes on planets on which jet engines don't work. Due to its great fuel efficiency it is also well-suited for interplanetary travel, but maneuvers take a long time to complete due to its low thrust-to-weight ratio - it is advised to use it for very small craft, and to use physics-warp while propelling with it.
It is practically impossible to build an ion-rocket which can defeat gravity on Kerbin, because the engine isn't even strong enough to lift itself against gravity, let alone itself and its fuel, a battery and a probe core. But when on a low-gravity moon like Minmus or Gilly it is possible to land, start, enter orbit and reach escape velocity with ion-propulsion alone. As of 0.23.5, it is technically possible to create an ion-powered probe, albeit with a minimum of parts, which will be able to defy Mun gravity. With that in mind, it is also possible to resist gravity with lightweight Ion craft on Duna, Moho, Dres, Eeloo, and every in-game moon with two exceptions: Laythe and Tylo have too high gravity for a single ion thruster, xenon tank, probe core, and battery.
Ion-powered "ferries" may also be useful for moving fuel, oxidizer and/or kerbonauts between two larger vessels, by keeping the large craft at such range that only one of them is within draw distance from the "ferry" at any moment, performance loss can be avoided. It is generally more fuel-efficient to move fuel and oxidizer between two ships using a ferry than it would be to dock the larger crafts together using their own engines and RCS.
Because it uses only about 0.485 units of xenon per second, one PB-X50R Xenon Container with 400 units of xenon can supply the engine for almost 14 minutes. The other larger tank PB-X150 Xenon Container with 700 units of xenon has enough to supply the engine more than 24 minutes.
The part.cfg lists the electrical consumption as 1.8 E which is the electricity consumed for 0.1 xenon. This is a ratio, and to propel 1 xenon an electricity of 18 E is required. As seen ingame, the fuel flow is 0.0485 kg/s or 0.4849 xenon/s. The electricity consumption is 8.7285 E/s. As the Isp given in seconds needs to be multiplied with a slightly higher acceleration (9.82 m/s²) than g0 (= 9.81 m/s²) the actual Isp in m/s is higher and therefore the xenon and electrical consumption is lower.
|“|| By emitting ionized xenon gas through a small thruster port, the PB-ION can produce incredibly efficient propulsion, but with a downside of very low thrust and high expense. The general perception of this engine as being powered by "witchcraft" has unfortunately given it a sour reputation.
— Ionic Protonic Electronics
|“|| By emitting ionized xenon gas through a small thruster port, the PB-ION can produce incredibly efficient propulsion, but with a downside of very low thrust and high energy usage. According to ISP Electronics sales reps, the rumours of this engine being powered by "dark magic" are largely exaggerated.
— Ionic Symphonic Protonic Electronics
The Ion-Powered Space Probe stock craft, powered by an ion engine.
- Ionic Protonic Electronics renamed Ionic Symphonic Protonic Electronics, description changed, thrust increased from 0.5 to 2, relative electricity reduced from 12 to 1.8.
- Initial Release
- Answer in the forum to Ion Engine consumes more energy than it should.
- In File:10X Xenon.png 10 PB-Ion engines are running at full power and consuming a lower value that 10× the theoretical value.