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0.17 A Joovan excursion


Ghery88
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Newly armed with Mechjeb, IIIG, edited patched conics and a borrowed protractor-ruler pair, I finally made it to the Joovan system. Enjoy.

Plotting course for aerobraking. Two quickloads later I figured out the following: real atmo starts at 130 km and a 127 km dip is perfectly enough for getting into orbit.

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Getting closer, there's Laythe on the left.

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Laythe getting closer. (No, not durning the initial approach, it took several orbits and manuvers.)

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Some background planet thingy.

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Something blue in the window.

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Navigating and landing among the Joovan moons was really tricky, since we were heading in the opposite direction. So our orbital speeds add up when it comes to braking. Mine was over 6000 m/s for four NERVAs to deal with using a quarter tank of fuel left. Luckily, Laythe has a decent atmosphere which starts to matter around 35 000 m, and gets really nice and useful at 9 000 m. So if I had planned this properly, I could've had descent parachutes... Instead this was bound to happen:

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At least the water is crystal clear.

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Edited by Ghery88
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Now how in the Kerbin are you going to rescue them? I hope Tomely, Munory, and Camgan are extraordinary swimmers.

also, How do you fly to Jool? I've done all the basics, the interactive Illustrated interplanetary guide calculator thing, even installed a mod that will tell me the exact planetary phase and ejection angles, but I can never get the glorious conix-patch intercept.

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Now how in the Kerbin are you going to rescue them? I hope Tomely, Munory, and Camgan are extraordinary swimmers.

also, How do you fly to Jool? I've done all the basics, the interactive Illustrated interplanetary guide calculator thing, even installed a mod that will tell me the exact planetary phase and ejection angles, but I can never get the glorious conix-patch intercept.

That's weird, I only have the above mentioned tools and it works like a charm for me. Make sure you have a capable craft and time everything right - the rest is just physics.

On the rescue misson, I don't know yet, for now they'll continue umm... science stuff. :)

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If you want to fly to Jool, you don't need any special mods. I did switch on the infinite fuel cheat but that was to learn how much re-design of every rocket I've ever used would be required. However, provided you have like the Nerva engine or an ion engine, or a lot of big tanks, here's what you do:

Leave Kerbal orbit and SOI. Orbit the Sun and when you come around it and Jool is in sight, point your craft at Jool, and SLOWLY expand your orbit until it just touches Jool. If you're an old hand at reaching the Mun, you will recognize this manuver on a MUCH larger scale. However remember that Jool's SOI is tiny on this scale. So you have to just KISS the orbit of Jool with your periapsis.

Then, you may need to fine-tune it vertically or horizontally. As you make your 250-day+ journey out to Jool, you may fine-tune it more to make sure you actually enter the Joolian SOI the way you want. It is possible. I've done it twice now, no mechjeb or calculator or any application. Just me and 2-level patched conics.

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I have a capable craft... i even have enough fuel left after missing Jool at the apoapsis to reduce my velocity to exactly 0 m/s, and do a perfect sundive. and after that still fuel left.

Now I kinda want to try that one out. :D

Oh, how could i forget? Jool is a bit inclined, make sure you match your orbital plane at the intersection. As above said, Jool's massive SOI is almost nothing on this scale of distances.

Edited by Ghery88
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Spikeyhat, plan your transfer a bit early then your calculations tell u. If that doesnt work, wait till u just pass apoapsis of the early transfer orbit and then burn up (like stick ur navball cursor on the north pole of the navball kinda up thing). That will move apoapsis back infront of you. Wait for you to pass your new apoapsis again then repeat until patch conics gives u an intercept. Love to explain how this works but im posting this via phone so just trust me.

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Spikeyhat, plan your transfer a bit early then your calculations tell u. If that doesnt work, wait till u just pass apoapsis of the early transfer orbit and then burn up (like stick ur navball cursor on the north pole of the navball kinda up thing). That will move apoapsis back infront of you. Wait for you to pass your new apoapsis again then repeat until patch conics gives u an intercept. Love to explain how this works but im posting this via phone so just trust me.

Inclination changes are really needy on delta V (and therefore fuel), I wouldn't recommend that.

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Jool is a bit inclined, make sure you match your orbital plane at the intersection. As above said, Jool's massive SOI is almost nothing on this scale of distances.

when launching, what degree point should i aim for on the nav ball? going in an inclined orbit to begin with sounds easier and more efficient that performing an inclination change.

Spikeyhat, plan your transfer a bit early then your calculations tell u. If that doesnt work, wait till u just pass apoapsis of the early transfer orbit and then burn up (like stick ur navball cursor on the north pole of the navball kinda up thing). That will move apoapsis back infront of you. Wait for you to pass your new apoapsis again then repeat until patch conics gives u an intercept. Love to explain how this works but im posting this via phone so just trust me.

By north pole of the nav ball, do you mean just the middle point on the blue side, or at the horizon pointed north?

Like which one of these?[ATTACH=CONFIG]33511[/ATTACH][ATTACH=CONFIG]33512[/ATTACH]

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when launching, what degree point should i aim for on the nav ball? going in an inclined orbit to begin with sounds easier and more efficient that performing an inclination change.

By north pole of the nav ball, do you mean just the middle point on the blue side, or at the horizon pointed north?

Like which one of these?[ATTACH=CONFIG]33511[/ATTACH][ATTACH=CONFIG]33512[/ATTACH]

I have only vague ideas on how to ascend to the correct incilination especially considering the future transfer burn... I rather preform the inclination change. And North means the horizontal North. Blue and brown apexes are the rad+ and rad- directions.

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I managed to get to Jool without even a protractor, just eyeballing it. I used the calculator at http://ksp.olex.biz/ and used the "That Looks About Right" method to time my burn. Went from Kerbin SOI to Jool in one burn, made another to line up with Laythe, and parachuted down to the surface. So far it's the only planet I've successfully landed on, but the only challenging part for this mission was launching a ship with enough fuel. Was I just ridiculously lucky?

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DA Second picture. I'm back on a laptop so I can explain my suggestion. It works because when you hit apoapsis of your transfer orbit, your craft moves slower around that point in its orbit then jool so it would be logical to position your craft infront of jool so as to allow it to catch up and take you. However, depending on the distance and how fast jool's closes, sometimes you end up dropping too far down in your orbit and jool will sail pass above you. To counter this, burning up will keep you from falling down to a lower orbit. Evidence is seen when you actually perform it: apoapsis will start moving to the front of your craft indicating that you will be climbing again. Do this enough times (may be 1 or 100 depending on how inaccurate you are) and patch conics will eventually tell you of an intercept.

i would perform the plane change after you've done your transfer burn. Just lay the map view horizontal so that your tranfer orbit looks like a flat line. Pivot your camera left or right until jool's orbit looks like a single straight line that intersect yours. At that point where they intersect is where you would perform the plane change so wait till your ship gets there. If jools orbit is heading down, burn on the 180 line at the equator of the navball. if jools orbit is up, burn on reverse side of the navball. It should be the N longitude at the equator. If you can't tell which direction jools orbit is heading, flip a coin and decide. Its easy to see the orbit change so you would know if you chose right or if you need to burn the opposite way.

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I managed to get to Jool without even a protractor, just eyeballing it. I used the calculator at http://ksp.olex.biz/ and used the "That Looks About Right" method to time my burn. Went from Kerbin SOI to Jool in one burn, made another to line up with Laythe, and parachuted down to the surface. So far it's the only planet I've successfully landed on, but the only challenging part for this mission was launching a ship with enough fuel. Was I just ridiculously lucky?

I did my Duna landing that way, but without the IIIG. Yes, that's insane luck or just a probability issue. :)

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, but I can never get the glorious conix-patch intercept.

In my experience it doesn't properly show the intercept until you are almost there. Probably because of the distance involved.

I managed to get to Jool without even a protractor, just eyeballing it. I used the calculator at http://ksp.olex.biz/ and used the "That Looks About Right" method to time my burn. Went from Kerbin SOI to Jool in one burn, made another to line up with Laythe, and parachuted down to the surface. So far it's the only planet I've successfully landed on, but the only challenging part for this mission was launching a ship with enough fuel. Was I just ridiculously lucky?

No, I think a lot of people like to make this all out to be harder than it is. I eyeball everything and also follow the "looks about right" method and I've managed to land everywhere I tried for. (Duna, Eve, Laythe, assorted moons.,)

Jool's soi is easy to get in to without any inclination changes etc, as are most of the planets.

Don't get me wrong, if you want to do all the math it is probably 10% more effecient, but if you build brute force ships and eyeball it well enough you can get all the same places and back with little planning.

Edited by _Aramchek_
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"No, I think a lot of people like to make this all out to be harder than it is. I eyeball everything and also follow the "looks about right" method and I've managed to land everywhere I tried for. (Duna, Eve, Laythe, assorted moons.,)"

I suppose it depends on whether you know what you're eyeballing. For instance, going to Eve efficiently needs a phase angle of 60 degrees(ish) which is easy enough to eyeball, but before I did the calculation I didn't know what I was looking for.

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