How do I travel to other planets?

[CaptainApollo]

Hello everyone! I want to start travelling to other planets in KSP, as I have been to Mun and Minmus! I know there are some videos, but I prefer learning from text. If anyone could tell me how to get to other planets, it would be much appreciated! Thank you!

[jkool702]

MOAR BOOSTERS

Sorry I couldnt help myself...

I find that using the NERV engine on a large craft with a detachable lander is the way to go. Possibly launch a craft over a few launches and assemble in kerbin orbit. In a lot of ways the answer really is more boosters, since you have to launch more fuel into space for the voyage. After unlocking the ISRU converter it gets easier, since you can refuel in flight by mining ore.

EDIT: here is a screenshot of my craft which is in Jool orbit. While there are plenty of methods that work, maybe this will give you some ideas

http://imgur.com/e6GpR3D

Edited June 22, 2015 by jkool702

[CaptainApollo]

Nice rocket! Thanks for the rocket ideas, but I was also talking about how I actually travel there, as in intercept an orbit and such.

[jkool702]

Once you leave Kerbins SOI you will be in orbit around the sun. Select your target and you will see ascending / decending nodes appear.

First correct your course exactly at an ascending / descending node (you will either burn normal or anti-normal), and this will align your orbit with the planet's orbit (you can plan this with a maneuver node).

Second, after your orbit is aligned use another maneuver node to prograde/retrograde such that your orbit intercepts. You will see two arrows representing your relative position at closest approach. play around with the maneuver node until the arrows are at the same place, and you will see the path change color (indicating your orbit will take you into the planets SOI).

Third, after entering the planets SOI burn retrograde so that you will be in an orbital trajectory (rather than an escape trajectory). you will officially be in orbit around a new planet

[63Hayden]

Nice rocket! Thanks for the rocket ideas, but I was also talking about how I actually travel there, as in intercept an orbit and such.

First of all, put yourself in a nice parking orbit around Kerbin, at say, around 80KMs. Next, place a maneuver node somewhere along your orbit, and go prograde until you leave Kerbin's SOI (sphere of influence). From there, select your target - I recommend Duna, as it is easy to reach, land on, and take off again - and continue pulling on the prograde node until the apoapsis intercepts Duna's orbit around the sun. If you do not achieve an intercept, go back to the space centre and accelerate time until you find yourself in a good alignment. From there, it's essentially the same as intercepting and orbiting the Mun or Minimus, except the main orbiting body is the Sun, not Kerbin. I should also say that you should download an essential mod called 'Kerbal Engineer Redux', as this will give you the performance of your rocket and spacecraft, which is essential in knowing if your spacecraft will be able to even make it to a target, whether you'll have enough fuel to land, come back, etc. As I'm terrible at explaining things, I suggest you go to Youtube and watch Scott Manley, the god of all things KSP, as he's done countless videos on this nature of gameplay.

[CaptainApollo]

Thank you Jkool! I was trying to select it as my target while I was still in orbit of Kerbin! So ok, orbit around Kerbol first. Thank you, I will try this tomorrow!

Thank you as well, Hayden. I will follow your advice too!

[Mic_n]

Can you rendezvous with another craft in orbit of Kerbin?

Then you can rendezvous with another planet in orbit of the Sun. Exactly the same principles, you just need to escape Kerbin's SoI first.

Also.. strictly speaking, you don't need to establish an orbit of Kerbin first.. You can just point straight up and keep on firing, though in the end you're not saving a heap of dV. If it's a planet further out that you're aiming for, take off 'forward'.. ie launch right at sunrise and go straight "up", which equates to Kerbin's prograde path in its orbit around the Sun. When you accelerate out, this will mean you're going faster than Kerbin and therefore climbing into a higher orbit. For planets inside, the opposite. Wait until sunset so you're on Kerbin's retrograde and again head on straight so that you're slowing down and dropping closer in in the solar system.

Edited June 22, 2015 by Mic_n

[CaptainApollo]

Not exactly, I was having some trouble with that in the tutorial Mic.

[selfish_meme]

http://ksp.olex.biz/ phase angle calculator, tells you the best positions the planets should be in to make a transfer

[Wanderfound]

The post above provides the technical info you'll need, but for the basic concept:

You know how burning prograde raises the other side of your orbit, while burning retrograde lowers it? And when you go to the Mun or Minmus, you burn so as to place your apoapsis ahead of the target, at the place it's going to be when you get there instead of the place it's at right now? And how when you leave the Mun or Minmus, you want to burn backwards along the orbital path of that moon so as to bring your periapsis in towards Kerbin (because you're burning retrograde relative to Kerbin, even though it's prograde relative to the Mun)?

It's like that, just bigger, with one complication:

When you're figuring out which way to aim your initial burn, you want to think of it as if Kerbin itself was the ship. So, if the planet is closer to the Sun than Kerbin (e.g. Moho), you want to leave going backwards along Kerbin's orbital path. In other words, solar retrograde. If the target is higher than Kerbin (e.g. Jool), you want to exit Kerbin burning along its orbital path: solar prograde. Kinda like what you do when you're returning from a moon, just on a bigger scale.

That calculator linked above will give you phase angle and ejection angle. Phase angle is the "where it's going to be when I get there" bit. It tells you what day to do the burn on. Ejection angle is the bit that aims your escape to either solar prograde or retrograde; it tells you where in your orbit to light the rockets.

[Mic_n]

Not exactly, I was having some trouble with that in the tutorial Mic.

Then I'd suggest working on that first. Maybe not quite as exciting but the mechanics are exactly the same and it's not as huge an effort to "get going". Replace Kerbin with the Sun and the other satellite you're trying to meet with another planet, and the concepts are the same. It's also really useful if you're wanting to do anything like a return mission or drop a little lander down to the surface of a moon or something and bring it back before progressing onto another body.

* Establish an orbit in the same plane as your target. That means burning 'down' (purple down-pointing triangle in your navball) at the Ascending Node or vice versa until the angle is ideally at 0.0 (ideally ideally 'NaN', which is like SUPER zero, but "close enough")

* Extend one point of your orbit to touch (not cross) the orbit of your target. Ideally, start your burn opposite the nearest 'node' of your target's orbit, so you're either pushing your Ap up to its Pe or reducing your Pe down to its Ap (unlikely if you're coming up from the surface of Kerbin to dock with a satellite, but what you're going to be doing transferring to an inner planet.) This should give you a single set of red markers to indicate the location in your orbit where your closest approach is (it'll be at the intersect of the two orbits) and another to indicate where the other object will be at that point. Two sets of orange and brown markers means your orbits cross. Not a problem in itself, but it's easier to follow and learn if you're only dealing with a single intersection.

* If you're in a lower orbit, you're following a shorter path with a quicker orbital period, so you'll "catch up" to that object with each orbit. Orbiting higher will let it catch you.

* Once those two markers are close, create yourself a manoeuvre node just before that intercept and adjust your prograde to fine tune it... As you adjust faster and slower you should see that "target position" marker move closer or further to your closest approach. You want to push your orbit so that those two markers get as close as you can get them.

At that point if you're doing a planetary transfer, that's quite possibly going to be 'close enough' to put you into that system's SOI, and you should be able to do some aerobraking to get captured and go where you want inside the system. However for a 'docking' kinda meet-up, you still need to zero your relative velocity. You can either do that with another manoeuvre node just past that "meeting" intercept that speeds up or slows down to match orbits and keep that 'target position' indicator in the same spot, or by switching your navball to "target" mode, waiting until you hit your closest approach (when your distance to target starts increasing again), lining up your retrograde marker there and burning until your relative velocity with the target hits zero.

To dock from there you need to point back towards your target and creep up on it. Properly balanced RCS or at least strong SAS is invaluable here. Watch your target indicator and prograde indicator and keep them both aligned (preferably over your centre marker). Line up your docking port with the target and hope it doesn't bug out

It's a tricky concept to get your head around, but muck around with it and you'll get the hang of it with time and practice. Don't try to go too quickly, and just do one thing at a time. It's really easy to get things wrong in a hurry.

Basically, play with manoeuvre nodes and see how changing your orbit in particular directions at particular points in your orbit impacts your rendezvous.

[CaptainApollo]

Wow, what a cool calculator! Thanks!

And thank you too, Wanderfound! This little guide of your is very helpful, and it will help me greatly tomorrow when I attempt a journey! I love the community!

I almost missed your post, Mic! But it is very helpful! I will follow this too, and I will actually attempt a docking first, that is a good idea! Thanks!

[Mic_n]

If you can take off into a circular orbit around Kerbin and then plan a manoeuvre node to meet the Mun, then you can take off at dawn, fly straight up until you're out of Kerbin's SOI to establish a circular orbit around the Sun and then plan a manoeuvre node to meet Duna. Exactly the same thing. Just a whole lot more dV and, if you don't hit a proper launch window, time

[FancyMouse]

This is the in-game version of the calculator, whose core code (Lambert solver) is written by the same guy who wrote the web version.

EDIT: apparently I was reading too fast and thought the earlier link was this (but in fact not): http://alexmoon.github.io/ksp/

Edited June 22, 2015 by FancyMouse

[CaptainApollo]

Interesting idea, I will consider using both of these strategies!

[Kryxal]

Just so you know, the best transfer orbit is one where you have your apoapsis/periapsis at the planetary orbits, which puts you leaving planetary prograde/retrograde (your exit track ends up parallel to your orbit) ... but you probably won't be able to do that. If you need to get there sooner, try launching a bit towards the sun, and to get there later, a bit away.

[CaptainApollo]

I'd like to get there sooner, so towards the sun sounds good for my intentions.

[FancyMouse]

Sooner or not you still need a transfer planner - a Lambert solver solves the equation of something under inverse square law (gravity being one of them) and then some initial conditions. The planner above solves the equation of: given two orbits (which are grabbed from game itself) and the time you want to travel (specified as range), what's the ejection angle and velocity required.

[CaptainApollo]

Interesting, very interesting. I will need one! There is so much science to KSP, I love it!