Getting to Eve with a probe

[Arctodus]

I hear its like Hotel California there - easy to get to, but you'll never leave

I'm just spit-balling a general idea here. I would very much like to use Eve to finish off my science, and I want to send a probe. My general mission statement is: it cannot be manned, and must use Ion engines (cause I've just unlocked them and they're still in the shrinkwrap), and must be able to do high and low orbit science. It should also be able to return from orbit to Kerbin (shouldn't be too difficult), and land if at all possible (I want full science marks, rather than transmitted, but I'm carrying a transmitter if necessary anyway). So, I'm wondering if anyone has any advice on probes and that

Here's what I have so far:

There's only one engine, but three gigantor arrays because I've yet to figure out how to group three ions into a triangle configuration on the bottom, without using the massive tricoupler. It'll be put into orbit on a rocket, cause I don't think it'll fit in the new cargo bays. From what I've got here so far, what do you guys think?

I'm also toying with the idea of attaching an Eve lander to the top, that will not be expected to return for transmitting surface science, but I'm not sure if that's better served in another mission.

Thanks in advance!

[Mitchz95]

Looks pretty overpowered, to be honest. You don't need three giant panels; two of the 1x6s will be enough as long as they're kept facing directly into the sun.

Here's a probe I made not too long ago. I designed it for a one-way trip to Gilly, but with some careful planning and aerobraking I probably could have gotten it back to Kerbin from Eve orbit.

If you keep the mystery goo units your TWR and delta-v will probably go down a lot (and the former will be low to begin with), so you may want to consider ditching those or sending them on another probe. Adding more fuel will get the delta-v back up, but it will make the probe heavier.

Lastly, the Communotron 16 is much lighter and power-efficient than the one you have now.

Edited October 18, 2014 by Mitchz95

[Arctodus]

Looks pretty overpowered, to be honest. You don't need three giant panels; two of the 1x6s will be enough as long as they're kept facing directly into the sun.

Here's a probe I made not too long ago. I designed it for a one-way trip to Gilly, but with some careful planning and aerobraking I probably could have gotten it back to Kerbin from Eve orbit.

http://oi59.tinypic.com/2jeny83.jpg

If you keep the mystery goo units your TWR and delta-v will probably go down a lot (and the former will be low to begin with), so you may want to consider ditching those or sending them on another probe. Adding more fuel will get the delta-v back up, but it will make the probe heavier.

Lastly, the Communotron 16 is much lighter and power-efficient than the one you have now.

Thanks for the reply!

The communotron has been replaced, the gigantor is now just singular, with two 1x6's and two OXSATS. Still got the Goo containers on at the moment, cause I wanna mine as much science as I can, but there's room to shift them if they're still too heavy.

There were initially three gigantors cause I wanted three engines, and I remember on the wiki it says one panel cover like 1.3 of an engine. I think I still want that, I was kind of inspired by this guys probe - I can't figure out how he did it:

http://forum.kerbalspaceprogram.com/threads/96377-the-new-cargo-bays-are-too-small/page4?p=1469832#post1469832

[metaphor]

You can use cubic octagonal struts to place as many engines as you want on the bottom. The cubic octagonals surface attach, so you can put them on in symmetry mode, and then put an engine under each one.

[LethalDose]

With ion engines, you need to drop any weight you can. Ditch those modular girder segments, that (I think) a quarter ton of dead weight. I think I see RCS tanks, but you don't need them. As mentioned above, you should use smaller panels for efficiency, especially since they'll be more efficient closer to Kerbol. You can probably even ditch some the Xenon.

Edit: I also agree with Mitch above, if you're gonna take the goo canisters, you're probably better off using a conventional (LFO) engine.

[Zylark]

You might want to look into a few mods to get your probes as tight, small and nice as possible. Especially the Near Future pack of mods.

My take on a little Eve Orbiter and Lander:

Already used about half of its fuel getting to an intercept with Eve. The top part is a tiny lander with plenty of sciency stuff in a tiny package thanks to the Universal Storage mod. Coming in at roughly 3.5 Tons when wet, it did not require much to get into Kerbin orbit. Getting it on an intercept to Eve did require two orbits though. I underestimated the electricity budget of that Argon-Electric Hall-Thruster. Or rather, the burn to Eve was not at an optimal angle to the sun and my solar-panels, essentially only getting about 2/3 of its' max electricity input.

Oh, and if in career, that thing was not cheap...

Edited October 19, 2014 by Zylark

[Arctodus]

You can use cubic octagonal struts to place as many engines as you want on the bottom. The cubic octagonals surface attach, so you can put them on in symmetry mode, and then put an engine under each one.

T'is a deep irony that those parts are what I'm hoping to unlock with this trip, lol.

I think I'll ditch the goo on good advice, and send that (and maybe a Science Jr. too ) later on, perhaps with the NERVA engine. This IS in career, so cost is a concern, but I'm fairly deep into it, so not too big a concern

I switched out the Communotron again, for the biggest - I know it uses most power, but I was hoping not to use it at all, its a last resort. Plus, it's massless

[michaelhester07]

There is a thing with KSP where any part with a weight less than .01 doesn't actually get counted against your ship's weight. I've noticed this in kerbal engineer and it seems to hold true. With that said, you can change up things on your ship to make it lighter:

1. Remove the goo experiments, carry the light 4: temperature, gravity, seismic, atmospheric

2. The unshielded solar panels are the same power output but slightly lighter than the shielded versions and will survive a trip through the atmosphere just the same when retracted.

3. The Communotron 16 is in the same massless category as you found out.

4. You can possibly create an analog of the solar panels with the small cube strut and the ox-stat. This would create a similar solar panel that falls in the massless category and net you deltaV off your ion engine

5. You don't need to tri-couple the ion engines if you know how to physics warp to counter long burns. hold the Alt key when you press the warp increase key. This will give you the 2x-4x warp you're used to seeing in atmosphere.

6. Missed one: Solar panels are more effective at eve's altitude than at kerbin's altitude. Solar panels near moho provide nearly limitless power.

Squad really needs to update the ship mass so that these .005 mass parts add weight correctly.

[moogoob]

Been doing a lot of ion stuff and probes, and I have to second the general opinion of "light, light, light". Slap as many massless components onto that thing as you can. OX-STAT's out the wazoo. I often get 12km/s of delta-v out of mine. That's good for a trip to several planets, if you plan it right.

Here's one design (my most recent, not my best but it works!)