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Ranger FCI-13: Fuel Cell Ion Powered Lander/Orbiter

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Recently, I've been messing around with using Ion engines powered by fuel cells. As it happens, the combined ISP of ion engines powered exclusively by fuel cells is a pretty respectable 1293 seconds. One large fuel cell can power two ion engines, so I built an all-purpose crew vehicle that uses 16 large fuel cells and 32 ion engines, allowing all 32 of them to be run at full throttle for as long as one's heart desires, and at any distance or occlusion to the Sun. It also comes with RCS thrusters and a forward mounted docking port. The command module has the standard decoupler, heatshield, and parachutes for return.


When placed in LKO using its launch vehicle, it has 4,100+ m/s of delta-v (vac) and an initial Kerbin TWR of 0.25.

When flying, keep in mind that the delta-v value that KSP will display on your staging diagram will be less than your true delta-v, because the game does not factor the consumption of lf/ox into the calculation. The ratio of rate of xenon to liquid fuel consumption is roughly 50.08, so the orbiter has 22,800 xenon to 450 lf (ratio of 50.66). This means that all three fuel levels stay roughly equal as a percentage of their initial value throughout the duration of the mission.

Because the Ion + fuel cell combined specific impulse is 1293 s, you can estimate your remaining delta-v in m/s at any point using this formula:

Delta-v = 9.81 * 1293 * ln ( m / 18.851 )

where "m" is your current mass in t.


The launch vehicle comes with the standard launch escape system (LES), with action groups:

ABORT: activate LES, separate command pod

AG1: activate LES, separate LES                                  (use prior to orbital insertion, or shortly after abort)

AG2: toggle fuel cells

AG3: deploy parachutes



Craft file: https://kerbalx.com/Jamie_Logan/Ranger-FCI-13










Hope you liked it! Check this out:



Edited by Jamie Logan
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  • 2 weeks later...
On 6/12/2020 at 12:21 AM, SPACE-MAN said:

Dude!!! The Ion lander is legit one of the coolest builds I've seen in a HOT minute!! such a beautiful execution of a large ion craft. Mad props!

That blimp is very nice looking too!


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I very much like the Ion ship you built! Super cool!!

I played around with the fuel cells as well, and made a fuel cell transport craft(too little power to be useful as a lander though) for shuttling around in space. Mine is more of a hybrid however, it uses both the fuel cells(when in a planet's shadow), and solar panels when it is exposed to sunlight.

Your ship is definitely better thought out, seeing as mine uses a greater amount of fuel compared to Xenon, whereas your craft is a bit more balanced. You calculated a fuel to xenon ratio for your craft at around 50... Mine came out to 95. I'll probably take inspiration from that and see if I can even that out a tad bit so I can dump the solar panels entirely.  

These my xenon shuttle:






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