Cant “find� Duna?

[Synapse]

Hey, first of all thanks for recommendations to use Mechjeb, but I prefer doing things manually.

I’ve built a sturdy lander and craft capable of landing on Duna, however I am struggling to intersect it’s orbit. My orbits are not perfect around Kerbin, they vary by a number of degrees. I can set up a manoeuvre node and drag it out to the orbit, but I have tried every slider and cannot find a “Duna encounter†anywhere! Zooming in the view around Duna helps a little, but no matter where I go I cannot encounter Duna. What am I doing wrong?

Edited July 2, 2013 by Synapse

[Flixxbeatz]

Planetary Phase Angles are your friend.

[Rune]

Yup. Your issue is that now you have to find those famous "launch windows" when the planets align and stuff. You could go with the angles like a pro, but you will have to either guesstimate them, hold a ruler to the screen, or install some navigational mod. Or if you want to do it even simpler, you can time things with the help of the launch calendar.

Rune. Which reminds me, I should timewarp more. The last 10 days before the first Jool window opens have been dragging along for a couple of game versions now in my savefile...

[Richy teh space man]

You could also use the protractor mod, that lets you know when launch windows are coming up, and when in your orbit you should begin your burn too.

[Synapse]

Is there a (rough) visual guide for this somewhere?

Also I find the time warp rather slow for some missions. I made a Voyager probe which was on a 36 year orbit of the Sun; even with time warp at maximum this took AGES.

[daveboy2000]

Or you could build overpowered rockets and just burn for it like me. Just get them into solar orbit and find a maneuver node that works.

[Flixxbeatz]

Or you could build overpowered rockets and just burn for it like me.

Going to any planet, using Orion NPP:

1- Wait until the target planet is a few degrees from the launchpad.

2- BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM BOOM

3- ????

4- PROFIT!

(carried over from a previous thread )

[SRV Ron]

Mun is easy because you can get an encounter window while in the first orbit around Kerbal. For Duna and the other planets, you will have to wait until the target planet has lined up to give you an encounter window. That, like real mission planning to Mars, could take years before that insertion window becomes available.

[Kimberly]

Because of the need to wait for launch windows, you might find it beneficial to prepare large missions in advance. By docking multiple craft together, you can create a single craft for travel to Duna that will launch probes, landers, rovers, etc. once you reach Duna orbit, and potentially split off some parts to send to Ike, as well. This will be easier than launching successive missions during the launch window and continually having to establish an orbit around Duna.

[Umlüx]

i recommend using the protractor mod. it's not an autopilot, it simply measures planetary alignments and shows you when to burn.

[AndreyATGB]

You don't have to use MJ's pilots if you don't want to. It's excellent for information (basically anything you could possibly want to know about your ship, orbit, phase angles etc.) and if you have a precise node that you struggled to get, it can execute them for you. Kerbal Engineering Redux has most of the same information, though I haven't personally tried it. As for doing it manually, use KSP olex and eyeball the angles. When you're in solar orbit, fix inclination if needed and wait until the nodes are relatively close (this may take a few solar orbits, depending on your eyeballing skills) then play with manuevre node until you have an encounter. Fine tune the Pe when closer to the intercept.

[Skorpychan]

i recommend using the protractor mod. it's not an autopilot, it simply measures planetary alignments and shows you when to burn.

That's incredibly useful-sounding. It'll make a find crutch until I can achieve my ambition of being able to eyeball things the whole way.

[Synapse]

Guys...I still don’t get it.

I’ve got a probe in orbit around Kerbol just outside of Kerbin’s orbit, with a full large tank and a nuclear engine. I’ve waited years and can’t encounter either Duna or Eve with manoeuvre nodes at either end of my orbit. Without using mods how is this possible?

[Crush]

Guys...I still don’t get it.

I’ve got a probe in orbit around Kerbol just outside of Kerbin’s orbit, with a full large tank and a nuclear engine. I’ve waited years and can’t encounter either Duna or Eve with manoeuvre nodes at either end of my orbit. Without using mods how is this possible?

First, set the planet as your target by clicking on it. Its orbit should now be colored green.

Remember that orbits are three-dimensional. So look for the ascending/descending node and get your inclination to the target planet as low as possible by accelerating north/south when exactly(!) on the node.

Then place a maneuver node and plan a burn which makes your orbit touch the orbit of the planet you want to encounter. Two "closest approach" markers should now appear on the orbit.

Drag the maneuver node around the orbit and watch how the "closest approach" marker moves. When your orbit is elliptical, you might have to adjust the burn duration of the maneuver node while you do that so it keeps touching the orbit. Get the "closest approach" markers as close as possible. Adding outwards and inwards acceleration to the maneuver node can also change where you encounter the planet. Playing a bit with it can help you to get a close approach even when far away from the ideal launch window.

A note about launch windows: Some people seem to have learned somewhere that an ideal launch window is required for a transfer to a specific planet. This is wrong. Yes, a transfer during the ideal launch window requires the least amount of fuel, but when you are willing to invest extra fuel, you can reach your destination at any time.

I never wait for a launch window when I do interplanetary travel. I just pack some more fuel.

When you feel like you need some practice: Learn how to dock, first. A rendevouz between two crafts in LKO is technically the same as a rendevouz between a craft and a planet in Kerbol orbit. Just with the difference that the scale is much larger and that you can only control one of the participants.

Edited July 3, 2013 by Crush

[Synapse]

Thanks Crush, that's very informative and I look forward to trying it out.

[Mr. Scruffy]

[...]Then place a maneuver node and plan a retrograde burn which makes your orbit touch the orbit of the planet you want to encounter. Two "closest approach" markers should now appear on the orbit.[emphasize added...]

For moving outwards from a kerbol orbit (like for reaching Duna from an orbit close to Kerbin´s) you will have to burn prograde.

[Synapse]

Hey Crush, thanks for the help. Last night I managed to crash my probe into the surface of Eve after getting the hang of those descent/ascent nodes. Tonight I hope to place a probe on the surface of Duna to collect surface samples.

[mellojoe]

I asked this once, as well: http://forum.kerbalspaceprogram.com/showthread.php/35465-How-to-eyeball-interplanetary-transfer

The answer I've come up with is using a website http://ksp.olex.biz

Read the info. Trust me, it helps. And it isn't a mod or a cheat or anything. It simply does the math for you, instead of you doing it by hand. And it gives you some basic pictures to follow. From there, I eyeball the angle instead of using a ruler or protractor or mod. Once you know what alignment the planets need to be, it simplifies things. And yes, sometimes this means time-warping for years and years to get a launch window for Duna or Jool. Go to the website, give it a read through.

[Mr Shifty]

Guys...I still don’t get it.

I’ve got a probe in orbit around Kerbol just outside of Kerbin’s orbit, with a full large tank and a nuclear engine. I’ve waited years and can’t encounter either Duna or Eve with manoeuvre nodes at either end of my orbit. Without using mods how is this possible?

1) Set your target planet as your target.

2) Set up a maneuvering node and add prograde or retrograde until the new orbit crosses the orbit of the planet you're trying to reach.

3) Add normal or anti-normal until the ascending or descending node of the new orbit is at the crossing point. This ensures that your new orbit touches the target planet's orbit in at least one place.

4) When you've got the AN or DN at the crossing point (or the inclination of the new orbit is close to the inclination of the target planet's orbit), you should see the "closest approach" markers. If the closest approach is close the crossing point, then adjust your maneuvering node to try to get intercept. You can look at the minimum approach distance and change each of the maneuvering node axes -- and the maneuvering node position -- to try to minimize it.

5) If the closest approach is not close to the crossing point, then place another maneuvering node just behind your vessel's position in your orbit. This allows you to "skip ahead" and see what the closest approach will be in the next orbit. You can keep adding maneuvering nodes, each one behind the other, to see successive orbits. Keep doing that until you get near your crossing point and then adjust your original maneuvering node for intercept.

[alexmun]

A note about launch windows: Some people seem to have learned somewhere that an ideal launch window is required for a transfer to a specific planet. This is wrong. Yes, a transfer during the ideal launch window requires the least amount of fuel, but when you are willing to invest extra fuel, you can reach your destination at any time.

Very true. If you want a visualization of what a launch window actually looks like, you can use my web app: http://alexmoon.github.io/ksp

[Dun Kirk]

I do the lazy option I get out of kerbin influence, then do a second burn to get an intercept by spinning the node around the orbit and adjusting. Getting an intercept on a planet is very delicate.

As others say there is a guide of the best time to launch.