reaching jool's moons in one go

[kurja]

I've tried a couple times to send a ship with half dozen probes to Jool, thinking I could disperse them to Jool's moons but there are some obvious challenges in doing this. Best I've achieved so far is probes on (or orbiting) three moons and Jool itself... Have you done something similar, and how did you succeed - or not?

[DrMonte]

Not yet but I have scheduled mannedkerballed mission to land on each moon of Jool.

[technion]

Are these supposed to be "return" missions? The challenge significantly increases where an exit from Laythe and Tylo are concerned.

[Johnno]

I haven't set out to do this myself but it shouldn't be too difficult, with a good approach. I'd suggest aerobraking the 'mothership' in Jool's atmosphere to begin with, leaving it in an orbit with a high AP, around the outermost moon's altitude (Pol, I think?). Once you get to that AP raise your PE slightly so it's not in Jool's atmosphere, detatch a probe and aerobrake that one in turn to lower its AP to the desired target's altitude, orbit insertion as usual. Rinse repeat for other probes.

[SSSPutnik]

Working on this too, trying to perfect Tylo return lander.

[celem]

This is how My first Jool mission is designed To work. So i'll follow this with interest. Im using ion'd probes To get The dv they need for orbiting while keeping interplanetary vessel light. Each then has a 48-7s To land

Edited December 3, 2013 by celem

[DrMonte]

- The idea would be to use Tylo for breaking instead of aerobreaking and leave mothership in near Tylo orbit. Circular might be better for docking. Returning home wouldn't cost much as lots of mass will be left here.

- Launch Ion probes from there (they cost almost nothing compared to all mission weight).

- Send separate landers with tug to each planet. One tug, multiple specialized landers.

The main challenge here is to prepare lander for each planet.

[kurja]

I'm doing this with just lander probes, so no need to return them.

In my previous try I did pretty much what Johnno suggested, I aerobraked around Jool to an elliptic orbit, gradually lowering my Ap thinking I'd detach probes at each moon's altitude. There were a few problems with this, one is inclination - changing that for each moon takes a lot of dv. I'm unsure if it would make more sense to have a huge dv carrier ship for that, or huge probes with enough dv to do that on their own - which would require a huge carrier ship. Another was simply that there's a whole bunch of moons there, I kept getting encounters where I didn't want them so two of my probes got flung out of the system... To clarify: if I detached a probe at an outer moon's altitude, at that moment I had both the carrier and probe at elliptic orbits; focus on the probe to get an intercept and the carrier got some encounter (it doesn't help that map view doesn't show encounter markers for unfocused ships!) ruining it's orbit, or vice versa. Then again if I immediately lifted probe's Pe to near-circular to avoid encounters, well that takes a lot of dv...

Practically, to make this work am I looking at a big ass carrier with six nuke powered probes on it?

[kurja]

- The idea would be to use Tylo for breaking instead of aerobreaking and leave mothership in near Tylo orbit. Circular might be better for docking. Returning home wouldn't cost much as lots of mass will be left here.

- Launch Ion probes from there (they cost almost nothing compared to all mission weight).

- Send separate landers with tug to each planet. One tug, multiple specialized landers.

The main challenge here is to prepare lander for each planet.

I don't follow, get to Tylo but don't aerobrake? Why? Also, wouldn't flying back and forth with that tug cost more fuel than just equipping the probes with their own?

[DrMonte]

I don't follow, get to Tylo but don't aerobrake? Why? Also, wouldn't flying back and forth with that tug cost more fuel than just equipping the probes with their own?

Passing near Tylo or other big Jools moon is enough to get you in to the Jools orbit without additional burn or need just some small corrections. That's not so simple to explain as aerobraking. Anyway that's an idea of ideal flight Aerobraking is always an option if something goes wrong.

If you'll think of a tug as a part of a lander then everything will get clear. For probes you wouldn't need that as they are not designed to return.

You might think of splitting the mothership before circularizing around the Jool. For example lowering a probe to Laythe or Tylo will require quite much dV but if you'll face them from outer space you'll be able to use your slowdown to Jool dV to lower your probe to Laythe or Tylo.

[Superfluous J]

I launched a 5-lander ship to Jool in my current series though it's not gotten there yet. I did test the landers in simulation sandbox mode with hyperedit so I know they are capable of it. Whether or not I'm capable of DOING it is another matter entirely

[Col_Jessep]

This is what I sent to Jool:

There were 6 probes on it originally. It worked pretty well except for the decoupler. It added weight on one side and I had not accounted for it. The probes fly fine at 20-30% thrust but I can't control them at full throttle.

Now, if you want to land on every moon things get a bit more complicated.

I send an extra mission to Tylo for a manned landing:

[kahlzun]

This is a Tylo-capable probe lander. Note that with the chute, that means this can land anywhere.

Also, i don't know what happened to the sepratrons in this shot.

I also have a manned land-and-return Tylo-capable craft, which takes advantage of the EAS-1 seats.

Apart from the balloons and Mechjeb, all my designs are stock here.

Edited December 3, 2013 by kahlzun

[DrMonte]

...

Apart from the balloons and Mechjeb, all my designs are stock here.

Balloons definitely gives no help for the Eve lifter

[lajoswinkler]

Make a fairly large tug with LV-N engine(s) and let it be a vehicle for your probes. Start with Pol. Play with gravity assists. Joolean system makes you do cool trajectories. No need for aerobraking.

[Geschosskopf]

I'm doing this with just lander probes, so no need to return them....

Practically, to make this work am I looking at a big ass carrier with six nuke powered probes on it?

Why not send each probe separately all the way from Kerbin? Flotillas of small ships all going in the same launch window are usually better than 1 big ship, especially for shotgunning the moons of Jool. There are so many and so far apart (vertically and horizontally) that you waste a LOT of dV moving around between them all. But with 1 ship per moon, you can tailor each transfer stage to the job it has to do, you can set each one's inclination individually and from outside Jool's SOI where it's cheap to do, etc. This is especially important for Bop.

[Troberg]

Done it. The beast was just above 8000 tons on the launchpad... Six landers, seven orbiting science satellites.

Just remember to put the mothership in a very high orbit around Jool, say halfway out among the moons. I didn't, and wasted lots of fuel getting to the moons.

Won't do it again. The ascent was a nice slideshow...

[Tw1]

I did it with ion engines, but bigger, mod ones. Many of the mod parts in this were also lighter than you can achieve with stock, unless you do something very clever.

This album was made to show my mission sequence, and the design stuff.

Javascript is disabled. View full album

It's still a pretty cool ship. At it to the already impresive pile here you can use for inspiration.

I called this probe Joolius Xena.

[jduchock]

I just parked my first fueling station above Tylo last night. i have two more fuelers to position before i send a Kerbaled mission to the surfaces...

things are so much easier in sandbox (but hardly a challenge...)

[Javster]

EnterElysium just did this a few days ago.

[kurja]

EnterElysium just did this a few days ago.

And he wrote of it somewhere? I can't find any recent posts from that username.

[Xephirious]

I'm working out the kinks on a Jool Probe Carrier right now. It has 4 ion probes, 2 with parachutes, 4 liquid fuel probes (for powered descent) and all probes have the 4 main science sensors.

I'm not sure how many bodies are in the Jool system as I try not to use the wiki too much so I'm bringing 2 variations of 2 different probes for a total of 4 configurations. The Kerbaled Carrier ship will aerobrake into an elliptical Jool orbit and will deploy the probes from Ap after planning the best approaches. Ion powered probes without chutes will head to low mass non atmospheric bodies, ion drives with chutes will head to high mass atmospheric bodies. Power descent probes (liquid fuel) will be deployed to high mass non atmospheric bodies or low mass atmospheric bodies.

EDIT: I will probly be sending at least a few of the probes out while traveling to the encounter. This will allow the Ion probes to travel more efficiently to highly inclined or highly elliptical orbits of Jool's moons.

Primary Kerbaled carrier ship will have the full array of science while the probes only carry the 4 small sensors. Carrier is powered by a skipper and two nuclear engines.

Once i get the bugs worked out and do the mission (probly tomorrow the 5th) I'll update if you'd like.

Edited December 3, 2013 by Xephirious

[DrMonte]

I'm not sure how many bodies are in the Jool system as I try not to use the wiki too much ...

Don't know. Playing blindly would send single probes for planet preview first.

[Superfluous J]

Why not send each probe separately all the way from Kerbin?

For the same reason I do everything in the game: I wanted to Also, my probe carrier got a lucky encounter with Vall and Laythe that got it into a great orbit without aerobraking. That wouldn't have happened to all 5 of my shotgun probes and I'm not good enough to MAKE it happen for any given probe and guarantee they end up where I want them to go.

[capi3101]

I've got a probe carrier en-route in my sandbox game; it will reach Jool's periapsis in three in-game days (it's already in Jool's SOI). It's carrying six "Sandstone" probes - an OKTO2 core w/Z-200 batt, two RTGs, a couple of science packages, an antenna, a 48-7S engine and an FL-T400 tank, 5,697 m/s delta-V in each probe if I've done all the math right - with the goal of putting one probe in orbit of each of Jool's moons plus Jool itself; the carrier will be taking a planetary dive when the job's done. Sounds like I'm trying to do the same thing as the OP; I'm also interested in "how do you do it" and will be comparing notes as time passes.

The carrier itself consists of a large RCU w/ Z-4 battery pack, 2 RTGs, an RCS system (due to the mass of the whole thing), 8 BZ-52s w/ 6 stack decouplers (to attach each probe radially; the other two are mountpoints for the engines), 2 LV-Ns w/ a girder setup for attachment to the booster and an orange tank. 5800 m/s of delta-V for the whole shebang. Thrust sucks of course but it did get me to Jool.