The Ultimate Jool 5 Challenge Continued

[sturmhauke]

58 minutes ago, Kerbolitto said:

There's some tiny ways to lower the weight of your payload, if you want me to elaborate 

I might keep that in mind for next time, but at this point I want to keep changes to a minimum.

[Starslinger999]

Im making final preperations for my Jool 5 with USI-LS and MKS...

Its going to be fun

[DerekL1963]

16 hours ago, sturmhauke said:

 

On my latest test flight I tested separating and redocking the two craft. This view is from the underside. 

  Reveal hidden contents

That is... impressive!

Edited August 21, 2018 by DerekL1963

[sturmhauke]

Thanks! I had to solve a couple problems and did a couple more rounds of testing. Here's some screenshots of my reentry test:

Spoiler

overshot the runway by a lot

 

coming back around

 

ran out of runway, but nothing broke

I think I'll be ready to launch for real next time.

[The Minmus Derp]

I'm designing something similar. But with only 2 landers. The tylo lander would have a bottom stage that would run out of fuel. The rest would refuel and go to Vall, and some more droptanks would fall off. The rest would refuel and land on bop and pol. (laythe, obviously requires a separate lander)

[sturmhauke]

It's cool seeing all the different solutions people come up with. I have a tendency to brute force it, but I am getting more efficient designs lately. I've been to one or two Jool moons at a time before, but never all in one mission.

[The Minmus Derp]

Yes, I agree.

[DerekL1963]

16 hours ago, The Minmus Derp said:

I'm designing something similar. But with only 2 landers. The tylo lander would have a bottom stage that would run out of fuel. The rest would refuel and go to Vall, and some more droptanks would fall off. The rest would refuel and land on bop and pol. (laythe, obviously requires a separate lander)

I also used a two lander design, though I used a refueling tanker/crew transfer vehicle which also served as the return vehicle.  The first lander had a crasher stage and drop tanks for Tylo, then the core refueled and landed on Vall, Bop, and Pol.  The dedicated Laythe lander was left in Laythe orbit rather than hauling it up out of the gravity well.

[The Minmus Derp]

Actually, I will use the (small) mothership as the lay the lander, because of laythe’s atmo

[Hummingbird Aerospace]

May one clip object such as fuel tanks into parts like the structural tube and the Kerbodyne-Rockomax adapter?

[JacobJHC]

Could you post a screenshot?

[sturmhauke]

I decided I needed some flags before I started the mission.

[The Minmus Derp]

4 hours ago, sturmhauke said:

I decided I needed some flags before I started the mission.

Whoo, Pretty!

[sturmhauke]

Val and Jeb are excited that the ejection burn has them temporarily aiming at the center of the planet. Nedler is not so sure...

[Kerbolitto]

8 hours ago, sturmhauke said:

Val and Jeb are excited that the ejection burn has them temporarily aiming at the center of the planet. Nedler is not so sure...

You can divide your injection in 2 or 3 burns, it greatly reduce those radial drifts

[sturmhauke]

Yeah I know, this is actually the 3rd and final burn. I did 2 to get the mothership on a 100 x 3000 km parking orbit, with the periapsis lined up on the ejection angle. After that I did an inclination burn a couple weeks out and was able to get a ballistic capture around Jool by using a Tylo gravity assist.

That's where I left off last night before going to bed. I'll post the pictures of the rest of the mission when I'm done.

[DerekL1963]

On 8/25/2018 at 7:20 AM, Kerbolitto said:

You can divide your injection in 2 or 3 burns, it greatly reduce those radial drifts

My preferred method is to depart from a parking orbit where the departure burn <=1/4 (or preferably 1/8) of the orbital period.  One and done without the chance for errors to pile up.

[Kerbolitto]

2 minutes ago, DerekL1963 said:

My preferred method is to depart from a parking orbit where the departure burn <=1/4 (or preferably 1/8) of the orbital period.  One and done without the chance for errors to pile up.

The easiest way I found to do this is to :

_Set a precise encounter with aimed planet 3 or 4 orbits later.

_Reduce the orbit count to 1 .

_Burn something like 1min before and cutting 1min after node (1 minute or whatever, as long as timing is very precise when I start / cut the engine).

_Repeat after 1 / 2 / 3 orbit with a random maneuver which is precisely set on Pe (just to get a timing on when to start / stop burning).

_Place a new maneuver node for the final burn, putting a tiny bit of radial if needed to account variation in timing due to 3 or 4 elliptical orbits delays (most of the time I don't have to).

 

After your first burn the Pe is exactly set for an encounter 3 or 4 orbits later and becomes your reference for 2nd/3rd/4th burn.

Only limiting factor is that you can't burn more than something like 800+ m/s because that put the ship in a highly elliptical orbit and can delay the final burn by a few days, which could then require some radial burn to minimize drifting due to this delay, for the final injection.

[sturmhauke]

Landing on Tylo is hard, you guys. I don't know how Jeb managed to survive this one. I guess he got scraped out of the command seat before it exploded.

[Hummingbird Aerospace]

On 8/24/2018 at 7:02 AM, JacobJHC said:

Could you post a screenshot?

https://wiki.kerbalspaceprogram.com/wiki/Kerbodyne_ADTP-2-3

As you can see, there is free space inside it.

https://wiki.kerbalspaceprogram.com/wiki/Structural_Fuselage

Same with this. If you don’t believe me look inside these parts in KSP.

 

I was also wondering about slight clipping with convert-o-trons into a fuel tank. If I’m not allowed, could I reduce the fuel level in the tank and clip the convert-o-torn in a bit.

 

[Laie]

On 8/25/2018 at 7:43 AM, sturmhauke said:

Val and Jeb are excited that the ejection burn has them temporarily aiming at the center of the planet. Nedler is not so sure...

You've done periapsis-kicking, that's already the final burn? Oh boy.

OK, it's probably over and done with by now, but the next time you come into such a situation I, too, recommend splitting the burn. That is, setting up a series of about-prograde maneuvers one after the other, with only brief gaps of perhaps ten seconds between them. Yes, that's lossy, but nowhere as lossy as beginning and ending your maneuver with what amounts to a radial burn. It's also far more precise, you don't need a 100m/s course correction right after the burn.

Hold on, I did just that not too long ago... here. I don't spend much time on the maneuver and guess the casual viewer would simply miss it, but pay attention when I leave Kerbin, at 40-43 seconds:

 

[sturmhauke]

1 hour ago, Laie said:

That is, setting up a series of about-prograde maneuvers one after the other, with only brief gaps of perhaps ten seconds between them. Yes, that's lossy, but nowhere as lossy as beginning and ending your maneuver with what amounts to a radial burn.

Hmm, I'll try that on the way back. I'm still in the Jool system working on the individual landings.

[JacobJHC]

On 8/27/2018 at 5:43 PM, Hummingbird Aerospace said:

https://wiki.kerbalspaceprogram.com/wiki/Kerbodyne_ADTP-2-3

As you can see, there is free space inside it.

https://wiki.kerbalspaceprogram.com/wiki/Structural_Fuselage

Same with this. If you don’t believe me look inside these parts in KSP.

 

I was also wondering about slight clipping with convert-o-trons into a fuel tank. If I’m not allowed, could I reduce the fuel level in the tank and clip the convert-o-torn in a bit.

 

Oh yeah, you can totally clip into those. Although try not to clip the convert-o-trons too much.

[sturmhauke]

This challenge has turned out to be more, uh, challenging than I expected, and I expected a lot. I'm nearing the end now - the landers for Tylo and Laythe have been recovered, and the Pol and Vall landers have launched back into space and are en route to Laythe to rendezvous with the mothership. Only the Bop lander has yet to arrive.

I underestimated the amount of dV needed for Val's "Valliant" Vall lander. She had enough to depart from the mothership (then in orbit of Tylo), land on Vall, and capture to an elliptical orbit at Laythe, but not enough to rendezvous without a lot of dangerous aerobraking first. (I'm using microlanders with command seats, except for the Laythe SSTO spaceplane.) I've gotten her orbit down a bit, but I might have to send one of the other landers to dock and rescue her. The Bop or Pol ion landers should have enough spare fuel.

[Hummingbird Aerospace]

On 8/24/2018 at 2:46 AM, sturmhauke said:

I decided I needed some flags before I started the mission.

How do you make those flags? Photoshop wizardry?