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My Jool 5 Attempt.


Kerbalstar

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Space Tug Update:

Here are the two space tugs I'll be using to construct the ship and dock everything in LKO. The Robinson is the large one and the Cena is the small one.

T9IIctx.jpg

 

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Kerbalstar out!

Edited by Kerbalstar
Space Tug not CSpace Tug!
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Looks good, as far as I can tell. If the staging display is correct, you have 4.4km/s of Delta-V, though...

Image result for ksp delta v map

It's about 2km/s for the Jool transfer. We'll assume you manage to capture with a Tylo assist. And the return is about 2km/s depending on what orbit you start from, although a gravity assist could also be useful. And then we assume direct entry at Kerbin. That doesn't leave much for moving around the Jool system. Capture into low Laythe orbit is at best ~800m/s, and Tylo is ~900m/s. That's 3.4km/s right there. IIRC the Bop/Pol numbers look scarier then they are, especially the plane change burn for Bop - timing that for apogee will be decently cheap.

I'd recommend 5-6 kilometers per second of Delta-V for moving around Jool. Plus more for the transfers. But really as much as you can fit in that sucker.

Although I do realize that as you use up your landers, your craft will become lighter, so factor that in. And go to your heaviest destination first to get rid of your heavy lander.

 

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Crew Transfer Vehicle Update:

I've designed the vehicle that will carry the crew to LKO, and will also carry them back down. (It will not be coming to Jool.) It's Soyuz... ish.

 

Q4Vf6YK.jpg

 

The crew will consist of 5 Kerbals.

 

Kerbalstar out!

Edited by Kerbalstar
Forgot my Kerbalstar out! Edit 2: Actually it's 5 Kerbals, not 4.
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Update:

The launch of the first module of the Milky Way was a success!

 

bsptE8H.png

 

  Reveal hidden contents
 

 

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Update:

The launch of Space Tugs Robinson and Cena was a success!

 

mI1sOMQ.png

 

  Reveal hidden contents
 

 

Kerbalstar out!

 

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Your Tylo lander being on the side could cause you some issues with roll. I would recommend using a 3.75m fairing, with an interstage truss that has a docking port at the top, so that you can put the lander in-line. This may necessitate some layout changes, but it will mean you avoid having your center of mass drastically offset from the center of thrust without losing the option to have an inflatable heat shield at the end (if that is your chosen method of capture at the Jool system).

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  On 1/21/2019 at 10:39 AM, septemberWaves said:

Your Tylo lander being on the side could cause you some issues with roll. I would recommend using a 3.75m fairing, with an interstage truss that has a docking port at the top, so that you can put the lander in-line. This may necessitate some layout changes, but it will mean you avoid having your center of mass drastically offset from the center of thrust without losing the option to have an inflatable heat shield at the end (if that is your chosen method of capture at the Jool system).

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Thanks for the suggestion! I looked at the CoM/CoT of the ship in the VAB, and the CoM is a bit over towards the Intrepid. I plan to add a reaction wheel to a couple of the future modules of the Milky Way. Worst case I can always use the Cena to move the Intrepid over to the docking port on top of the Milky Way. I'm planning to use a Tylo assist to capture at Jool. I don't know how, but @5thHorseman has a nice video I should watch, that I'm sure will explain it all. A heat shield on the front might be easier, but it's heavy and the ship already has low DV. Question for @Ultimate Steve: I've seen some of your Jool ships (The Robinson X and the Voyager ), and it looks like you just put the landers on the sides. Was there any sort of rhyme or reason? Did you have to specifically design landers to balance the mass, or was it a little off, but the reaction wheels compensated?

ZDPUega.jpg

 

Kerbalstar out!

 

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Gravity assists to capture at Jool are not overwhelmingly difficult. Getting an encounter with Tylo or Laythe is easy enough as long as you plan it early on in the interplanetary transfer, because tiny changes in orbital speed (of the kind of magnitude which makes them easily accomplished using RCS thrusters) can make huge differences to the time and angle you enter the Jool system.

The real difficulty with gravity assists is planning them properly when you want to use another planet to boost your solar orbit (i.e. Kerbin ==> Eve ==> Jool); that takes practice and a lot of planning, and I typically do not bother with it because I am impatient (and in my new playthrough it will be impractical for crewed missions anyway because of life support). Gravity captures are far easier to do.

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  On 1/21/2019 at 9:54 PM, Kerbalstar said:

Question for @Ultimate Steve: I've seen some of your Jool ships (The Robinson X and the Voyager ), and it looks like you just put the landers on the sides. Was there any sort of rhyme or reason? Did you have to specifically design landers to balance the mass, or was it a little off, but the reaction wheels compensated?

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It was a little off, and I had reaction wheels to compensate. In some cases I also thrust limited some of the nuclear engines to help. For those two missions I didn't have to design the craft to carry very many Kerbals or significant cargo, so they were really small and didn't matter that much compared to the size of the mothership. If I had landers the size of yours, I would definitely design them to balance or be mounted in-line. I only bring it up because your landers are so huge. I think I've built an Eve ascent vehicle smaller than your Tylo lander. Not to put down your landers or anything, it's really, REALLY good to have margin on Tylo, especially since you've got that large rover there.

Another thing to think about is docking port rigidity. Having three jumbo tanks plus other stuff hanging off of one normal size docking port is not going to be fun, especially mounted 90 degrees to the thrust vector. I'd consider autostrutting the thing once in orbit (quicksaving first!) and/or moving that lander to the top port, and either finding a way to mount the Laythe lander more centrally or maybe docking a liquid fuel tank of equal mass to be used as a drop tank for the ship, dropping it once you reach Laythe.

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  On 1/22/2019 at 2:01 AM, Ultimate Steve said:

It was a little off, and I had reaction wheels to compensate. In some cases I also thrust limited some of the nuclear engines to help. For those two missions I didn't have to design the craft to carry very many Kerbals or significant cargo, so they were really small and didn't matter that much compared to the size of the mothership. If I had landers the size of yours, I would definitely design them to balance or be mounted in-line. I only bring it up because your landers are so huge. I think I've built an Eve ascent vehicle smaller than your Tylo lander. Not to put down your landers or anything, it's really, REALLY good to have margin on Tylo, especially since you've got that large rover there.

Another thing to think about is docking port rigidity. Having three jumbo tanks plus other stuff hanging off of one normal size docking port is not going to be fun, especially mounted 90 degrees to the thrust vector. I'd consider autostrutting the thing once in orbit (quicksaving first!) and/or moving that lander to the top port, and either finding a way to mount the Laythe lander more centrally or maybe docking a liquid fuel tank of equal mass to be used as a drop tank for the ship, dropping it once you reach Laythe.

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Okay, thrust limiting might be good. They’re that big? Fair point. Maybe I can have module 2 (which is just fuel reserve for the Voyager anyway), put on the side and Intrepid on the front.

Yeah, you’ve got a point there.

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