How do I get the autopilot to work?

[triscuits]

I purchased the game today and am still working on orbits. I've managed to get some successful circular orbits but they always seem to go off course and crash into kerbin. I'd like to get it so I can have it on windowed mode in the background just orbiting without my help. Is this possible?

Is the autopilot in game functional? If it is how do I get it to work?

[OdinYggd]

There isn't an autopilot in the manner you're probably thinking, at least not as part of the stock game. If your ship has an ASAS on board you can set it to maintain a heading, but that is about the extent of what it can do. The default hotkey for this is T, and should make the SAS indicator on the navball turn white.

Most likely you're looking for the kind of functionality that comes from MechJeb, which adds a great deal of intelligence to the ship's automation and is capable of guiding the ship through common tasks with only minimal input from you. It's a great learning tool in this regard, because you can learn how to do it manually by watching how mechjeb does it.

[Bunsen]

Once you're in a proper orbit the game will do exactly what you want, no piloting (auto- or otherwise) involved. If you're finding that the ship crashes into Kerbin, either you weren't in orbit (or were orbiting within the atmosphere), or you were orbiting so far out that an encounter with Mun or Minmus threw you into a reentry trajectory (unlikely). Hit http://wiki.kerbalspaceprogram.com/wiki/Tutorial:_How_to_Get_into_Orbit and pay particular attention to the bit about getting your whole orbit above 70km.

[Nibb31]

If you are crashing, then you are not in orbit. An orbit is an elliptical trajectory that circles Kerbin. Getting into orbit simply involves reaching orbital speed (2300m/s) with a periapsis (=the lowest point in your orbit) above the atmosphere (70000m). You should read the tutorials at the top of this forum.

Once you're in orbit, you can leave your spacecraft indefinitely, it won't fall down. One way of putting it is that it's going so fast that it falls beyond the horizon. That's the beauty of spaceflight.

There is no autopilot in KSP. There is a mod called MechJeb, but I strongly recommend that you get the basics of orbital mechanics ironed out before using it.

[Uberick]

What everyone else said; if you are crashing, you are not in an orbit. Check your map to see the shape of your orbit. Unless it circles the entire planet, never dropping below 70km at your lowest point(periapsis), you do not have a stable orbit.

As far as autopilot is concerned, MechJeb can automate certain functions, but that is a mod(check the spaceport). Stock KSP does not have any autopilot. The SAS and ASAS are only stabilizers, SAS will attempt to counteract roll and ASAS will attempt to hold your ship on its current heading, but they will only do this while SAS(to the top right of your NavBall) is activated. To activate or deactivate SAS, press T be default.

On another note; Welcome to Kerbal Space Program!

[airlynx99]

FWIW, I bought the game a week ago and spent just as much time watching videos on how to fly as I did actually flying. The nodes that you create in map view are very helpful, but they do not execute themselves. MechJeb was a great help, but a bit overwhelming at first. Before jumping into MechJeb I'd suggest being able to plot nodes and execute them successfully. Also, if you create a node with a long burn time (over a minute) it sometimes helps to start your burns a bit before your actual node. (something I learned from MechJeb)

Also, MechJeb is not a perfect autopilot, it requires some babysitting sometimes. My first attempt at leaving Kerbin's orbit for Moho I relied entirely on MechJeb and it started a 5 minute long retrograde burn on my periapsis, I never did figure out why. Naturally I just started plummeting back to Kerbin, and to fix it I had to burn up more fuel and was left with empty tanks circling the sun. I leave that flight there as a lesson to not trust the autopilot all the time.

[Merinsan]

Perhaps he is in an orbit, but below 70km? Either way, what the others have said. You need your orbit to be above 70km. I personally aim for about 80km just for some wriggle room.

If your orbit is below 70km, the atmosphere will slow you down slowly over time causing the orbit to decay until you crash. How long that takes depends on the height of your periapsis.

[astropapi1]

What's this autopilot he's talking about?

[SDIR]

They are talking about Mechjeb 2.0, a sort of autopilot mod

[astropapi1]

They are talking about Mechjeb 2.0, a sort of autopilot mod

Yeah, I know about mechjeb, I even use it sometimes; but I don't think he would go and install MJ right after getting KSP.

[triscuits]

No I wasn't talking about Mechjeb, though I have heard of it. I was talking about those buttons in map mode that pop up when you click on your trajectory. They seem to be some sort of AP system, maybe I'm reading it wrong.

But anyway I think I figured out orbiting (sort of) thanks for the help.

[KerbMav]

Why wouldnt he?

Perhaps he is using the nodes and thinks it is like plotting a course and "engage!", which it is not.

I personally like the manual flying - but I see some windows which are kinda interesting - does MJ mess with anything as long as you do not specifically ask it to?

[Strategia]

I personally like the manual flying - but I see some windows which are kinda interesting - does MJ mess with anything as long as you do not specifically ask it to?

MechJeb does absolutely nothing unless you tell it to. And like you've probably noticed, it also has a variety of useful passive information windows. Vessel Information does pretty much what KER does as well, to my knowledge, Orbital Information gives you a neat little readout of everything pertaining to your orbit, and Surface Information displays all sorts of useful stuff as well, including true altitude (as opposed to altitude above sea level (0), which is what the altimeter measures), which is extremely useful when performing a powered landing on higher ground. I use it a lot for these purposes.

[Bunsen]

No I wasn't talking about Mechjeb, though I have heard of it. I was talking about those buttons in map mode that pop up when you click on your trajectory. They seem to be some sort of AP system, maybe I'm reading it wrong.

Yeah, those are called "maneuver nodes" and they aren't an autopilot so much as a "what if?" and planning system -- it shows you where you'd go if you burned for a certain amount of delta-v at a certain time. It will also tell you (on and next to the nav ball, as long as you're not in cockpit view) the direction and magnitude of the delta-v, so you can accurately perform a planned burn. Pointing your ship the right way, firing the engines at the right time, and shutting them off at the right time are still up to you.

[Tiron]

MechJeb does absolutely nothing unless you tell it to. And like you've probably noticed, it also has a variety of useful passive information windows. Vessel Information does pretty much what KER does as well, to my knowledge, Orbital Information gives you a neat little readout of everything pertaining to your orbit, and Surface Information displays all sorts of useful stuff as well, including true altitude (as opposed to altitude above sea level (0), which is what the altimeter measures), which is extremely useful when performing a powered landing on higher ground. I use it a lot for these purposes.

The landing module also predicts orbits after aerobraking and estimated landing site including the effects of atmospheric drag, I'm not sure there's another mod out there that can do that.

[Mr Shifty]

Here's a great (and short) maneuver node tutorial: