Important!

[BenniYT]

Hi Guys, i wan't to fly to the Jool and Laythe with an little Satelite. (Of course separate)

The Sattelite is a little Stayputnik Probe with an Antenna and "Gravitatiometer" and of course to move with a few Solar Panels and Xenon Tank and the "Dawn" Engine

(about a ton weighs my Satelite)

But my "Malinkij 12"("little 12")-Rocket can only fly back if i don't make an Jool-Orbit (what i of course want to do). Has anyone an Idea how to build a Rocket that can do this job? When yes please tell me how i should build it.

Money doesn't matter, i try it in Sandbox Mode.

[BenniYT]

Hi Guys, i want to build a rocket that can easily fly to Jool and back, does anyone have an Idea to build a rocket like this?

[Cpt Kerbalkrunch]

That's a pretty open-ended question. You can get as many different answers as their are guys on the forum. What's your missing profile? Is this a manned mission, or just a simple probe? F you're bringing Kerbals, how many? Which moons do you intend to visit? Are you going to land anywhere? If so, are you going to drill? There's a lot to do around Jool. It's an absolute blast. You just have to decide what you intend to do, then design a ship that can do it.

[Starman4308]

As usual, work backwards through the mission. Design something that can return the crew (if any) from Jool. Beneath that, have something to do everything you want to do in the Jool system. Beneath that, have your Jool transfer stage, etc.

Mission, then payload, then vehicle.

[Human Person]

Hmm. Take a Control pod or probe core, add stuff and fuel tanks, then engines. Add a decoupler so you can separate stages, those are very important and can help a great deal in increasing your rockets capabilities. Have something to generate electricity, like an RTG.

[Geonovast]

Just now, Physics Student said:

Have something to generate electricity, like an RTG

I think this a big one.  Solar panels are pretty useless that far out.  Array of RTGs or some sort of fuel cell.

[Spricigo]

well, for that vague question I have some vague idea.:

1.I'd build the part of my rocket that I want to bring back and strap enough parachutes so it can slowdown enough to not crash.

2. Protect the craft with heatshield or/and fairing so it can resist reentry heat.

3.Attach to it engines and fuel tanks to perform the necessary maneuvers  to bring the vessel from Jool to Kerbin.

4.Attach to it engines and fuel tanks to perform the necessary maneuvers to send the vessel from Kerbin to Jool

5.Attach to it engines and fuel tanks to put the vessel in orbit from the surface of Kerbin.

Along that process I'd make adjustments (adding more stuff) accordingly to the objectives and necessities of the mission. So I will wait your clarification about the details of the mission before trying to offer more specific advice.

Also, we have no idea of ho much experience or skill you have. It will be considerable hard to offer useful advice if you don't have at least a bit of experience/familiarity with the game, in particular some concept of rocket design and orbital mechanics  Likewise you will have a lot of trouble executing a complex interplanetary mission without some more basic concepts sorted out.

[Ten Key]

Moved thread to the Gameplay Questions area of the forum.

[Cpt Kerbalkrunch]

Ah, this sheds much more light on your question about going to Jool. To send a probe shouldn't be too difficult depending on your skill in the game, as @Spricigo said in your other thread. Are you familiar with the concept of gravity assists? If so, you can use Tylo or Laythe to capture at Jool for free. This should save you enough Delta V to make the rest of your mission pretty easy.

And welcome to the forum!

Edited January 12, 2018 by Cpt Kerbalkrunch

[Ten Key]

Merged two threads on the same topic from the same user together. These two threads were originally in different areas of the forum, but as they are both gameplay questions, they both belong here. And since they are both the same gameplay question, they belong together. 

Carry on.  

[Cpt Kerbalkrunch]

And now that we know what your plan is and what your ship consists of, if I had to make one suggestion (purely as a personal opinion), it would be to dump the Dawn. I know their ISP is unmatched, but their "power" is a joke. And the further you get from the sun, the less sense they make. A small probe with a Spark and a few Oscar B's can get surprisingly far. And it would actually have the power to make maneuvers.

[Spricigo]

Just now, Cpt Kerbalkrunch said:

And now that we know what your plan is and what your ship consists of, if I had to make one suggestion (purely as a personal opinion), it would be to dump the Dawn. I know their ISP is unmatched, but their "power" is a joke. And the further you get from the sun, the less sense they make. A small probe with a Spark and a few Oscar B's can get surprisingly far. And it would actually have the power to make maneuvers.

One could suggest exactly the opposite, to take advantage of the high ISP, despite its lack of power. The Dawn engine will suffer less from a bad mass fraction so it can have better deltaV bugged even with extra generators, batteries or even more engines, OTOH the 2kN of  thrust may be enough as long the craft don't become too heavy. Anyway, given how much that is a matter of opinion/taste, that is to each one to decide. (For the record: my gripe with the dawn engine is the energy requirement and consequent thinkering about what generator/batteries to use and also the dry/wet mass fraction of xenon tanks. I still use it in some situation but more often I just go with the much simpler and cheaper ant or spider.)

 

 @BenniYT please, provide a (few) screenshot(s) of your vessel and a brief description of how the mission is going, so we can give better advice.. Among the detail that may be useful for us is how much deltaV and time your maneuvers are taking and how they are setup.  Your problem can either be a design problem (your craft lack performance to execute the mission) or a piloting problem (you are not doing the mission in a efficient way) or even a mix of the two, so we need to figure out which one before we propose a more effective solution.

 

So far there is something that I consider a clear design flaw: the Stayputinik is a very basic(cheap and low-tech) probecore that don't have SAS or built-in reaction wheels, there is no reason to use it in a sandbox game except looks or self-imposed challenge. I'd go either with the RC-001S Remote Guidance Unit, the Probodobodyne HECS2 or the Probodobodyne  OKTO2,  depending on how  I'm concerned about mass, functionalities and/or part count.

[Aegolius13]

1 hour ago, Spricigo said:

One could suggest exactly the opposite, to take advantage of the high ISP, despite its lack of power. The Dawn engine will suffer less from a bad mass fraction so it can have better deltaV bugged even with extra generators, batteries or even more engines, OTOH the 2kN of  thrust may be enough as long the craft don't become too heavy. Anyway, given how much that is a matter of opinion/taste, that is to each one to decide. (For the record: my gripe with the dawn engine is the energy requirement and consequent thinkering about what generator/batteries to use and also the dry/wet mass fraction of xenon tanks. I still use it in some situation but more often I just go with the much simpler and cheaper ant or spider.)

My general take is that the Dawn is only worth the cost, slowness, etc. if you need a LOT (like 10,000 m/s plus) of delta-v for your mission profile.   I'm not entirely sure what OP is looking to do, but it sounds like send a probe one-way to the Jool system?  That could take under 3000 m/s with good gravity assists, or may be few thousand m/s more depending on the maneuvers.  In any case, it sounds like the mission could be accomplished with a couple stages of small chemical rockets, or maybe a nuke, so that the payload to LKO is not too big.    But ions seem like overkill, on top of the brutal ejection burn from Kerbin. 

All that said, it's perfectly doable with a Dawn if OP wants to give that tech a try.  

[DunaManiac]

You should build a rocket, get KER and have a delta v map, and build! It's that easy.

[Foxster]

10 hours ago, DunaManiac said:

You should build a rocket, get KER and have a delta v map, and build! It's that easy.

This is where you need to start. 

When tackling these longer missions it is important you have a idea beforehand the dV requirements of the mission (dV map) and then have a tool that tells you your craft's dV capability (MJ or KER). 

Edited January 13, 2018 by Foxster