Ion Hovercraft on Mun. Possible to achieve?

[protoz]

Making this thing is not easy, I came down to this layout. 4 ion + 1 xenon gas leaves you .0872 free mass or 19 solar panels this will cancels out gravity on the Mun, any extra thrust will make you float. Given this, it takes 16 solar panels to power 1 ion, so clearly you can't scale this w.o a massive battery storage. Using 8 ion 1 gas setup leaves you with .1361 free mass.

I don't want to make a craft that has enough fuel for 1-5 minutes, or one that has enough battery life for few seconds, this requires massive scaling and precise calculations. Possibly the hardest thing i've set out to do.

Edited May 27, 2013 by protoz
Typo

[cpt_nosh]

Nevertheless one of the most interesting, never thought about that.

[Scub]

I'd be very interested to hear of your progress on this. If you can pull it off it would be major.

[protoz]

Its not possible, at least not on 1.63 surface gravity or on Unity's single core capabilities.

This is what i came down to. 800 parts, not even the bare essentials yet. It literally took a minute to load this thing on the runway, and this rig can run any game on max w.o a problem, i could of swore i played .19 with a +2000 part spacestation and loaded faster then i did just now. But regardless I got 16,000 battery power, 0 xenon gas and .91666 free mass in those screenshots. Unless you think you can fit enough fuel and additional batteries on .91666 mass and willing to play at .005 frames per second, this isn't possible.

Edited May 26, 2013 by protoz

[sadron]

Darn it Unity, stop not-multithreading!

[Scub]

Maybe the solution is not to attempt to achieve a constant hover. But rather a very shallow bouncing like mode of transport. Similar to the way the Kerbel's hop along the surface of the moon, with something added for forward momentum.

[Flixxbeatz]

Its not possible, at least not on 1.63 surface gravity or on Unity's single core capabilities.

This is what i came down to. 800 parts, not even the bare essentials yet. It literally took a minute to load this thing on the runway, and this rig can run any game on max w.o a problem, i could of swore i played .19 with a +2000 part spacestation and loaded faster then i did just now. But regardless I got 16,000 battery power, 0 xenon gas and .91666 free mass in those screenshots. Unless you think you can fit enough fuel and additional batteries on .91666 mass and willing to play at .005 frames per second, this isn't possible.

-snip-

Is your computer ok? Or got its insides reduced to molten pile?

[satcharna]

Would it be easier to do using the medium sized thrusters from Hybrid Pack or KSPX?

[protoz]

Maybe the solution is not to attempt to achieve a constant hover. But rather a very shallow bouncing like mode of transport. Similar to the way the Kerbel's hop along the surface of the moon, with something added for forward momentum.

Ya i'll make that in a sec, kind of defeats the purpose of having 4200 ISP ion engines if you have to cycle them.

[protoz]

Would it be easier to do using the medium sized thrusters from Hybrid Pack or KSPX?

I haven't tried KSPX yet & it doesn't seem like theres a wiki for the parts, i don't know what the medium thruster specs are.

[satcharna]

2.5 power, 4200 isp, 12 electric charge and 0.1 xenongas for propulsion, mass 1. It's quite balanced, just larger. I imagine that since you no longer need to add structural parts to put them on, you could save some weight.

[protoz]

After some number crunching this is what i came down to.

It will hover if you can get rid of .05 mass. That means, the seat has to be removed.

So it will hover to an extent of battery life & then it'll require recharge, and its 8 ion drives on 1 xenon gas.

It will have .013 thrust, exactly 6 minutes of fuel, and 9-10 seconds of hover before battery needs recharge.

2.5 power, 4200 isp, 12 electric charge and 0.1 xenongas for propulsion, mass 1. It's quite balanced, just larger. I imagine that since you no longer need to add structural parts to put them on, you could save some weight.

Its a lot better since it requires 5x less power.

About my previous statement, i lose .08 mass from hanger to runway im not sure whyb but the seat can stay.

This is the best thing i could come up with as mentioned earlier.. 6 mins of fuel, 10 second hover + seat + light, and nice rover control while not hovering.

Well now thats been done, i think i could probably take on Minmus w. a hovercraft that can hover for hours lol.

Edited May 26, 2013 by protoz

[protoz]

After testing this firsthand on the Mun, i have to admin it was a lot of fun. It handles really nice, i did use cheats to get infinite energy to see how it maneuvers. W. cheats off as stated above, it will run for 6 mins, 10 seconds at a time, w. .013 thrust. It the finished product is essentially the picture ontop of this page, i just re-arranged solar panels. Heres it in action.

Its somewhat doable on Mun, i have a pretty optimized version, on anything less then 1.63 gravity is what im looking forward to now. Dres's 1.13 will make it 50% easier then Mun, so i think i can make one that hovers for up to hours self sustained.

[Tristavius]

I tried this concept on minmus once (even less gravity to contend with). I came to the conclusion that a manned one simply wasn't possible - I could get the TWR but not with anywhere near enough solar panels to stay afloat for more than a small period of time.

Perhaps now with the external seats it would be possible to revisit the idea. Of course heading to Pol or Gilly may help further aswell.

[karolus10]

Not better use large solar panels on airless body ?

[protoz]

I tried this concept on minmus once (even less gravity to contend with). I came to the conclusion that a manned one simply wasn't possible - I could get the TWR but not with anywhere near enough solar panels to stay afloat for more than a small period of time.

Perhaps now with the external seats it would be possible to revisit the idea. Of course heading to Pol or Gilly may help further aswell.

I'm looking at Dres or Minmus, Dress will have 2x more yield cargo space & Minmus will have 3x.

I have no doubt minmus will be self sustained stay afloat for hours on end, same with dress just with less xenon gas. I mean Mun... it came down to getting rid of a single light, or a seat, but it turned out mechjeb was giving me .008 off on the weights from hanger to runway, so i was able to keep both w. .005 mass to spare.

Not better use large solar panels on airless body ?

Solar panels i used are the most efficient, they are more efficient then the 2x3 OX-4 Photovoltaic Panels ones by .0042 for every 2e/s, and yes the, it comes down to those kind of little numbers. The craft i ended up with, if its .005 over, it won't fly until you burn some xenon gas.

[protoz]

https://mega.co.nz/#!GMx1Bb7Z!ex-MfHeZqXC8GGd39OziuwbUsyoD2skot10gho2QYas

Heres the .craft file, i did some more tweaks on it, its perfect besides the left side in mass/thrust hanger view, i don't know why. If you add anything to this it won't fly, not even .001, you've been warned.

Its stock + mechjeb, which i forgot to remove off the craft.

Let me know how it handles.

Edited May 26, 2013 by protoz

[Mihara]

Wait, if you've come to those little numbers, maybe you know already and I can save some frustrating experiments:

Assuming I have to place one cubic strut (the smallest one) for every small solar panel, do they still stay more efficient in terms of mass than the foldable ones?

[protoz]

Wait, if you've come to those little numbers, maybe you know already and I can save some frustrating experiments:

Assuming I have to place one cubic strut (the smallest one) for every small solar panel, do they still stay more efficient in terms of mass than the foldable ones?

http://wiki.kerbalspaceprogram.com/wiki/Parts just look at the efficiency for solar panels, i think thats what your looking for.

[protoz]

http://wiki.kerbalspaceprogram.com/wiki/Parts just look at the efficiency for solar panels, i think thats what your looking for.

The only drawback to the small panels, which are most efficient, is the part count. Meant to reply in one post.

[Szkeptik]

Why don't you try it on Gilly?

[Mihara]

Because there is nothing to try on Gilly, the first ion lander you try just works. :-)

[automcdonough]

dang, i had thought the 6 panel unfolding type were more efficient. :/

[Mihara]

The only drawback to the small panels, which are most efficient, is the part count. Meant to reply in one post.

I've just been trying to produce an effective Really Long Range Ion Mapping Probe.

So far, the results have been disappointing, either it runs at full power but I don't get more than 3000 dV, at which point I'm better off with liquid fuel to do what I set out to do, or it has 6000 paper dV but every attempt to make use of it wastes most of it on burns it can't actually complete.

[drakesdoom]

I've just been trying to produce an effective Really Long Range Ion Mapping Probe.

So far, the results have been disappointing, either it runs at full power but I don't get more than 3000 dV, at which point I'm better off with liquid fuel to do what I set out to do, or it has 6000 paper dV but every attempt to make use of it wastes most of it on burns it can't actually complete.

If you are looking for a place for an ion engine the only place I have found them useful is on communication satellites. A secondary ion engine can adjust your orbit to be very precise after using other means to achieve a rough orbit.