My Jool 5 Attempt.

[Kerbalstar]

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.

 

 

Kerbalstar out!

Edited January 20, 2019 by Kerbalstar
Space Tug not CSpace Tug!

[Ultimate Steve]

Looks good, as far as I can tell. If the staging display is correct, you have 4.4km/s of Delta-V, though...

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.

 

[Kerbalstar]

Thanks, @Ultimate Steve! So, you’re saying I’ll have to be careful with my DV?

Also, shoot, out of likes. Remind me tomorrow.

[Kerbalstar]

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.

 

 

The crew will consist of 5 Kerbals.

 

Kerbalstar out!

Edited January 21, 2019 by Kerbalstar
Forgot my Kerbalstar out! Edit 2: Actually it's 5 Kerbals, not 4.

[Kerbalstar]

Update:

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

 

 

Spoiler

 

(OOC: From this point forward I will be writing the mission outside of spoilers as me, Kerbalstar. I will be writing the story inside of spoilers from the point of view of a Kerbal, most of the time Moberry Kerman, a female scientist.) 

 

2 months ago.

"We chose to go to Jool's moons, and to do the other things, not because they are easy, but because they are hard." - President of Kerbin, Steven Kerman. I was sitting in my apartment, hoping for a call-back from the KSP Kerbonaut Corp. I was filled with excitement at first. Then my scientific brain kicked in and I started to wonder how we would accomplish such a great feat. Then the phone rang.

Now.

"What are you doing, Jeb!" Val shouted.

"Flying the rocket, Val," Jeb replied, not paying much attention to her.

"Then why are you on your phone?" Val asked.

"The SAS is on, and this thing isn't a flipping risk, Val," Jeb said.

"You're playing a game? Give me the controls!" Val said.

"Fine, I'll pay more attention," Jeb said, as he set down his phone. "See, nothing went wrong."

"Not yet," Vall said.

I was standing in Mission Control at the Kerbal Space Center, watching a rocket launch. Jeb was (supposed to be) flying the rocket. Val was standing behind him, watching his monitor, and apparently him.

"Is it always like this?" I whispered to Bob Kerman.

"Pretty much," He replied. 

"Why?" I asked.

"Val and Jeb... have very different personalities," Bob said.

I still felt intimidated being around the veteran Kerbonauts all the time. 2 months ago, I was in my apartment wondering if I would be selected to be a Kerbonaut. Then I got a call, and suddenly I was training with the 4 most famous Kerbals in the world, for a mission beyond anything that we had ever done. It's amazing how much things can change in just two orbits of The Mun. 

"See Val, everything's fine. And... orbit!" Jeb proclaimed from his seat in the front of Mission Control.

 

 

[Kerbalstar]

Update:

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

 

 

Spoiler

Overall, this launch was a success, with a couple of problems. The first problem was that during the rendezvous Jeb left on a snack break, and didn't come back till the tugs had gone past the Milky Way. Somebody else could have flown it, but I guess they were all on lunch break or something.

Second, when the Robinson was docking with the Milky Way, it inexorably rammed into the side of the docking port, flew away at high velocity and broke a solar panel. Luckily Jeb was able to salvage the situation. 

 

 

Kerbalstar out!

 

[septemberWaves]

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).

[Kerbalstar]

11 hours ago, 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).

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?

 

Kerbalstar out!

 

[septemberWaves]

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.

[Ultimate Steve]

3 hours ago, 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?

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.

[Kerbalstar]

16 minutes ago, 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.

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.