Discovered some faults in the way I operate my rockets...

[Tortoise]

Seeking help,

Well first of all, I can get into orbit with no problem. But when I try to send another rocket out to dock with one rocket, I just get into orbit then keep burning in the direction of the rocket until I arrive (Which never worked), I end up going all around the solar system, then escaping for some reason..

And when I try to return to earth while I'm escaping, I'm fully burning towards the earth but I'm still being sucked into an escape. Can you guys help me?

Edited April 15, 2014 by Tortoise

[wasmic]

Sounds weird. You should definitely watch some tutorials on rendesvouz, that'll probably help.

Also, if you're on an escape trajectory, don't burn towards Kerbin; burn retrograde to kill your velocity instead.

[brooklyn666]

Orbital Mechanics 101

[Superfluous J]

Seeking help,

Well first of all, I can get into orbit with no problem. But when I try to send another rocket out to dock with one rocket, I just get into orbit then keep burning in the direction of the rocket until I arrive (Which never worked), I end up going all around the solar system, then escaping for some reason..

And when I try to return to earth while I'm escaping, I'm fully burning towards the earth but I'm still being sucked into an escape. Can you guys help me?

It sounds like you're not waiting for the proper time to do your burns. You need to use maneuver nodes and the orbits in map mode to get your ships near each other. Once they're within a few km of each other, THAT is when you start worrying about if you're going towards it on the Navball.

It's very challenging, difficult, non-common-sensical, and rewarding to do. Keep up with it, peruse Scott Manley's tutorial videos, and keep up with it.

[psyper]

You're not in kansas anymore toto! Seriously though you need to forget everything you learned from movies like Gravity - pointing at an object in space and heading towards it will cause all kinds of problems if its far away and you're both orbiting a planet like Kerbin or that mythical planet you call earth. You need to learn a bit about prograde, retrograde, radial and antiradial maneuvers to be able to intercept the orbits of other craft or to land back on the planet. Rule of thumb for that is just to keep burning retrograde (backwards) until your orbit drops below 69 km and let gravity and the drag on the atmosphere bring you the rest of the way down.

To catch up with another ship you need to make your orbit lower that the target so that you are traveling faster - I tend to think of it as runners on a circular track - the inside lane will catch up with the outside lane as he has less distance to go - you're basically aiming for where he's going to be rather than where he is now.

You really need to watch scott manleys videos - if anyone else hasn't you need to do that now - I'd start with his 101 basics - taking off and rendezvous videos:

I believe his videos should be required watching before attempting anything on kerbal but thats just me! oh that and the 5thhorsemans ones (^^^up there) - too - his is awesome - Very much a kinda documentary on the history of kerbal space flight! and you go through all his problems and solutions with him - very good at getting a feel for the issues you'll encounter along the way.

Have fun, fly safe and talkatyou later

[JiWint]

^ One does not simply point an object and burn to it.

[Aphobius]

I was honestly feeling like beating the OP with a long stick (literally).

But I thought, what the hell is wrong with most of the people on this forum, my head always hurts when I read it.

So I've made a little research and found this:

Physics education

Physics education in American high schools

Physics is taught in high schools, college and graduate schools. In the US, it has traditionally not been introduced until junior or senior year (i.e. 12th grade), and then only as an elective or optional science course, which the majority of American high school students have not taken.

Really?

What I wanted to find was that they teach you the laws of motion in the forth grade or so. But a whole nation (I assume that most people here are from the US) that never heard at least about the laws of motion. What the hell?

Anyway, now everything that happens here makes sense.

[wasmic]

I was honestly feeling like beating the OP with a long stick (literally).

But I thought, what the hell is wrong with most of the people on this forum, my head always hurts when I read it.

So I've made a little research and found this:

Physics education

Really?

What I wanted to find was that they teach you the laws of motion in the forth grade or so. But a whole nation (I assume that most people here are from the US) that never heard at least about the laws of motion. What the hell?

Anyway, now everything that happens here makes sense.

Teaching the laws of motion in fourth grade? What the hell? Children at that age don't even know what algebra is!

[FREEFALL1984]

To the OP I dont want to sound harsh but I'm amazed you made it into an orbit to begin with.

anyway, remember these rules.

1- low is fast, to catch up on a target, fly lower than it.

2- High is slow, to allow something to catch up on you, fly higher than it.

3- if you match the targets orbit, then you match the speed.

4- if you match the targets speed then you match its orbit.

5- Every time you burn the engines or RCS, you change your orbit, your ship traveling towards something is the result of the orbit passing the targets orbit,

6- moving around in space doesn't work in straight lines, everything is always bendy.

7- Never burn "towards" something, unless you're on a close approach to a target in which case use small RCS burns and don't loose track of your relative velocity.

Also as mentioned before, just forget everything you ever saw on TV about travelling through space,

[MockKnizzle]

I'd argue that fundamental natural principles are far easier for a child to understand intuitively than how to move little symbols around on paper.

Look what happens when we push an object, it keeps moving!

Look at the dial on this spring scale, when I use it to pull this object with this much force for three seconds it ends up going this fast! But look what happens when I pull on this other, bigger object... it ends up going slower!

Okay, stand up and push on a partner's hands on the count of three... *kids go flying* Look, when you apply a push to something, it ends up pushing back on you!

[Superfluous J]

I was honestly feeling like beating the OP with a long stick (literally).

I feel the same only not towards the OP.

"I want to learn something I don't know!"

"I want to beat you with a stick!"

[Red Iron Crown]

I feel the same only not towards the OP.

"I want to learn something I don't know!"

"I want to beat you with a stick!"

Seriously. Orbital mechanics are counterintuitive when compared to the ground-based physics we're all accustomed to. There's no shame in being confused by them or asking for help.

Edited April 14, 2014 by Red Iron Crown
Removed superfluous word.

[MarvinKitFox]

Orbital Mechanics for Dummies.

Normal text is narrative: within (brackets) denotes a rule to remember.

When orbiting a mass...

The lower your orbit, the faster you are moving.

(slower=>down) To go down, slow down. this will cause your orbit to drop lower, which speeds you up even more than you slowed down, but leaves you at a lower height

(faster=>up) To go up, speed up.

(left and right change your angle)

left or right change your orbit angle, but bring you right back here after 1 loop

(Orbit has 2 sides), so change here only causes a change on the other side

No matter what you do, your orbit will always intersect your current position. You are only changing the *other side* of your orbit. This means most orbital actions are two-phase things.

One action to change the other side of the loop, and another action when you are on that other side, to change your originating side to match.

In your example, to get back to the planet that is rapidly dwindling in the distance. You want to go down, so use the rule (slower=>down)

Dont burn towards the planet, burn towards where you came from, i.e. retrograde. This will decrease the displayed orbital speed, which by the above rules (slower=> down) will take you back to your planet. Once you are close to the planet, you will want to slow down *again*, to again use both (slower=>down) and (orbit has 2 sides) to bring down the other side of your orbit from the lofty heights you came from.

With this in mind... How to intercept. For not-quite-dummies, but easy enough once you stop panicking. This guide assumes you are at least in the same sphere of influence, interplanetary transfers are a whole tougher bucket of crabs!

1) match your orbital plane with your target. Without this, life becomes complicated. To match orbital plane in KSp:

a) in map mode, look at your orbit from above. Select your taget. You will see two dotted lines joining the two orbits, with tiny scribbles AN an DN at the intersection with your orbit. Also a number showing the angle of error.

this AN and DN are the only places where you can change your orbit, where the end result could match your target in inclination. Use (left and right change your angle) by burning 90degrees to your orbit at the AN or DN, until the displayed angle is small enough. If your orbit is just rotating around without changing angle, you have the wriong 90 degrees!

with matched orbital planes, a simple burn prograde will stretch your orbit outwards, and a retrograde burn will stretch it inward. Use either (slower=>down) or (faster=>up) to make a maneuvering node that will change the other side of your orbit to touch your target's orbit. When it does, you get markers saying where you will be, and where target will be at closest match. Most likely it will not match right now. Cancel the node, orbit a bit, and repeat. You will soon enough either figure out the relation for when to shift your orbit, or after enough tries get a reasonable match. Execute this best match.

c) When you get to your target's orbit, and being reasonably close to it, make a new node to put yourself into the the same orbit your target has. only once your orbit looks virtually identical to your target, AND your target is quite close to you along the arc, do you regard your target in with normal eyes. You should be close enough, and moving slowly enough in relation to it, that you can use "normal" 3-d motion to get to it.

I hope this makes sense...

Orbital mechanics is very counter-intuitive, for us ground-dwelling flatlanders.

[Claw]

Seriously. Orbital mechanics are counterintuitive when compared to the ground-based physics we're all used accustomed to. There's no shame in being confused by them or asking for help.

Indeed.

The forum exists for people to ask questions. We should be proud that something like KSP creates enough interest that a person actually asks how real things work.

Plenty of others are posting good info about orbital mechanics. Perhaps also try putting down a maneuver node (left click on the blue orbit in map mode) and pulling on only one axis at a time. Watch what that does to the orbit. It might not make sense at first, but might help as you watch videos or read more.

Take your time and try not get too frustrated. It's a lot of learning and isn't always obvious what is going on. Orbital mechanics requires a bit of patience. Truthfully you can ignore nearly all of the math to start off with, so try not to let the equations scare you off.

[psyper]

I feel the same only not towards the OP.

"I want to learn something I don't know!"

"I want to beat you with a stick!"

This.

I used to think that I knew more than average about space and science - the amount I know since playing and learning from ksp has been 10 fold what I knew before! Its a great way to learn about orbital mechanics but everyone has to start somewhere. If you feel like you need to hit someone with a stick - hit them with the stick of knowledge.

[Ninjatsu]

Are you say....looking at Kerbin and making the rocket point towards it and then burn? Try not to do that, rather use the navball on the bottom middle of the screen.

Check out both the recommended guides from brooklyn666 and 5thHorseman.

After the tutorials try getting into an orbit (blue ring around Kerbin) then stop burning, doesnt have to be circular any type of oval will do. Press F5 to do a quicksave. From here now you can experiment with how the navball and orbits work.

Navball Basics :

1)Look at the ball, shift your craft around the ball so you see the 2 different green reticles. The green reticle that has horizontal and vertical lines means your current travel direction, the other reticle with the diagonal lines is opposite of your current travel (So pointing at the diagonal and burning until your m/s reaches 0 means you will be going nowhere until gravity pulls you again).

2)Solar Map view, click on a planet/moon (not the current SoI planet, so if you around Kerbin you can't target Kerbin) set as target. Shift around the navball again, 2 new reticles in pink. (Brainfade...Not 100% sure from here lol) Circle and dot is the current direction of planet/moon, with the other pink reticle being the direction away from the planet/moon.

3)Click on the blue orbit ring, set up a new manoeuvre node. A circle with X/Y/Z Reticles pops up (hey these look familiar!). The green reticles mean forwards and backwards as they did on the navball. The Purple/Pink ones are slightly different, these are used to move yourself vertically upwards or downwards. The last 2 blue reticles are there to shift your orbit slightly like a hoola-hoop, basically these try to keep the same circle/oval but try to shift it around you (gravity from planets/moons will alter your circle/oval, these are best for adjustments to vessels before getting close to docking). Right clicking will allow you to either delete the manoeuvre node or tell it to wait a full orbit and do the manoeuvre during the next orbit (well 2 buttons, add an orbit or minus an orbit). Holding the mouse delicately over 1 of the reticles and either dragging or scrolling will start to shift the amount of velocity/burn you want in that direction, this will slowly start adding an altered orbit in orange that shows what will happen if you correctly burn for the manoeuvre node.

4)Click on the m/s above the navball. There are 3 settings, Orbit - Surface - Target. Changing these will track your speed relative to the object being tracked, and will also change the green reticles based on what is targeted. (Targeting the Mun, then setting navball to target will display the m/s deifference between you and the Mun. Aiming at the diagonal green reticle and burning to 0m/s will have you moving at the same speed as the moon in the same direction. It will slowly change as gravity pulls you back. This is used heavily for rendezvous and docking).

Now that you have a quicksave to mess with, and a bit of jargon above you should be able to start messing with manouver nodes a bit and get a bit of understanding of which directions to burn.

Using your eyes and looking at the rocket and its direction is a bad habit, I still do it and I still get my directions wrong. Use the ball, be the ball, become one with the ball.

[Tortoise]

Thank you guys so much! I appreciate it.

[Starwhip]

How many times am I going to write the same exact post to everyone who asks?!?

Link. In sig. Go to it. Learn stuffs.

[Tortoise]

My main problem is orbital alignment!

[Starwhip]

Yes, that's there too. I think the section was called "Setting up the launch".

EDIT:

Yep, it's there. Scroll down quite a bit, there's a few pictures of the correct alignment.

[pizzaoverhead]

Seriously. Orbital mechanics are counterintuitive when compared to the ground-based physics we're all accustomed to. There's no shame in being confused by them or asking for help.

Not only is there no shame in having problems with understanding orbital rendezvous, NASA had the same issue.

[RW-1]

Seriously. Orbital mechanics are counterintuitive when compared to the ground-based physics we're all accustomed to. There's no shame in being confused by them or asking for help.

+1

I thought is more amusing to read the OP and think about all that fuel wasted in the direction of the first rocket, a chase that we all know would take him everywhere but where he wanted to go.

But that's half the battle, getting there, to the OP, then you have to dock ....

[RW-1]

Not only is there no shame in having problems with understanding orbital rendezvous, NASA had the same issue.

Yep, later on it was also because the orbits were not as aligned as could be, you know how bad SK can be as your paths diverge.

[cantab]

Yup, welcome to orbital mechanics! Don't worry, with a bit of practice it'll start feeling natural enough.

Most things have been covered very well by the other posters. I'll just add:

You'll do almost all your rocket flying on instruments - the navball and the map view, basically. You may want to make the UI larger, there's a slider in the Main Menu settings.

Keep these two Wiki pages handy: http://wiki.kerbalspaceprogram.com/wiki/Basic_maneuvers and http://wiki.kerbalspaceprogram.com/wiki/Key_bindings

[vetrox]

Definatley need new ingame tutorials asap

To align your orbits you will want to setup a maneuver node at the Ascending/descending node and play around until your inclinations match.

When i first started playing, i knew the very basics of getting to orbit but everything else I thought was a case of "point at it and burn!" oh How i've learned.

I was honestly feeling like beating the OP with a long stick (literally).

But I thought, what the hell is wrong with most of the people on this forum, my head always hurts when I read it.

So I've made a little research and found this:

Physics education

Really?

What I wanted to find was that they teach you the laws of motion in the forth grade or so. But a whole nation (I assume that most people here are from the US) that never heard at least about the laws of motion. What the hell?

Anyway, now everything that happens here makes sense.

Even if basic physics was taught earlier in life there is still a difference between "physics 101" and orbital mechanics. I was taught the real basic stuff when I was 14 at school but never was it mentioned how stuff in space worked. Is there really a need to teach orbital mechanics in highschool/preschool?