Still struggling to get into orbit ...

[JackBush]

I think I'm getting closer; I'm understanding what I have to do. But it's the execution. Often as I'm ascending I find my ship is passing or overshooting the Apoapsis. I came close a couple of times but missed the timing for meeting the node. But how can I keep the Ap rising without catching it and passing it?

I know you're all way past this point but I've spent days trying to understand and get to it and it's very frustrating. I don't have Mechjeb and I don't want to get it, but it's beginning to whisper to me in the back of my head. I very much like Orb8Ter's tutorial and he's gotten me the closest but there's still these little problems I come up against. And I don't seem able to conserve my fuel as he does.

Sorry to babble on.

Edited October 2, 2015 by JackBush

[ghpstage]

But how can I keep the Ap rising without catching it and passing it?

Generally when trying to get to orbit you burn to the horizon, to push back the apoapsis all you have to do is turn upwards from the horizon.

The effect it has will depend on the angle between your heading and the horizon as well as your TWR.

[ForScience6686]

I would guess you're either launching too vertical and don't have timeto circulize, or you're not packing enough fuel. Your launch would be a gradual turn that lands you horizontal and in orbit. Need more specifics on the situation you're facing.

[Kryxal]

A ship with the delta-v readout from either KER or Mechjeb would help, and a general description of your ascent (such as initial turn of so much at some point, pointing so far at 10k, 15k, 20k...)

[GoSlash27]

Jack Bush,

If you burn more horizontal, it will extend your apopasis further prograde. This gives you more spacing in time while still adding velocity without raising it.

Check it out:

http://wikisend.com/download/969842/SRBLifter.craft

Download and install this simple rocket and observe the path it follows in the first stage.

Don't engage SAS or touch anything, just launch it watch what it does.

This rocket has been set up to execute a near- ideal gravity turn without any input from the user.

http://s52.photobucket.com/user/GoSlash27/slideshow/KSP/GravTurnBoosterDemo

If you mimic this flight path during your launch, it will drop you right into orbit without overshooting your altitude or passing your apoapsis.

Good luck!

-Slashy

[Superfluous J]

If you have the ability, a youtube video of your launch would do wonders.

Fly in map mode, with an eye on the navball. Never deviate from East, and only change your vertical aim from 90 (straight up) to 0 (straight sideways). One problem with being in map mode is you can't stage, so watch your staging in the lower left and when you must stage, hit M, then space to stage, and then M again to go back into map mode. Complain on the forums that this is bad, like we all do

When you get to about 50-100m/s, pitch over about 5 degrees, to 85. Hold that until your apoapsis (which you can click on in map mode to get it to stay up the whole time) gets up to about 2000m, and then pitch to 80degrees. Continue to pitch 5 degrees every 2000m until your apoapsis is at 20km and you should have pitched over 50 total degrees, so you're aiming at about the 40 line (still pointing East!). If your prograde marker tends to always be above you and you seem to be pulling it down, you've probably got too much thrust. If it sinks below you you've probably not got enough. A little difference is fine, but if you spend a lot of time outside the prograde circle you're not being super efficient, and (much worse) your rocket could become squirrely and/or flip uncontrollably.

Then hold that until your apoapsis gets to 30km, and pitch down to 30 degrees. 40km apoapsis, pitch to 20 degrees. 50km, 10 degrees. 60km and on, hug the horizon line.

Edited September 25, 2015 by 5thHorseman

[The_Rocketeer]

If you've passed your apoapsis, you're no longer ascending, you're falling. The apoapsis represents the highest point of your orbital path. If that point is behind you, you're on your way down, if it's in front then you're climbing towards it.

You can make your apoapsis higher by thrusting vertically upwards, but this will just mean you go steeply up and then steeply down. To reach orbit, you need to fly along the ground until you're travelling so fast across that when you fall, you miss the ground and just keep falling. So, apoapsis is important to be sure that you'll be high enough at some point to be in orbit, but much more important is to raise your periapsis to a similar altitude. To do this, thrusting up won't help at all, and you have to thrust sideways, usually along the equator.

If the problem is that you're unable to reach these speeds before you pass the apoapsis, the issue is probably either that you're not following a very good flight profile, or that you simply don't have enough thrust. The thrust issue is solved by using more engines or using bigger engines.

The ascent profile is more complicated. You need to be ascending quickly enough to get out of the draggy atmosphere, but at the same time you want to build up as much horizontal speed as possible as soon as you can. I usually start by tilting 5 degrees straight off the launch pad, and switch my speed display to 'orbital' instead of 'surface'. Watching the prograde marker on the navball, I steer gently to meet it at an attitude of about 60 degrees. Then it's a case of steering to bring the prograde marker down to about 10 degrees climb by the time the craft reaches about 25,000m. Then I switch to map view and try to bring my apoapsis up to orbit altitude (usually 75km to give a safe margin to atmo). Once the craft is in space, I boost the apoapsis back up to 75km (it will have dropped due to atmo drag), and then make another burn around the apoapsis to circularise, i.e. bring the periapsis up to the same altitude.

This is almost certainly not the most foolproof or efficient burn to orbit, but it's the seat-of-my-pants technique that I've settled into.

If this is no help at all, try to give us some more details of where the ascent is going wrong, what altitude you're meeting the apoapsis, whether you're reaching space, what your craft looks like, etc.

[G'th]

Welp, if you're passing up your apoapsis, then the problem is likely a combo of your rocket and your ascent path. Your rocket is likely too weak (or just plain not big enough) and your ascent path is likely too shallow to properly get up into orbit.

I know you don't want MechJEB, so what I recommend instead is to get VOID or KER. The reason being that they'll give you more readouts of what your rocket is doing, how fast its going, how high it is, etc etc. Using one of those mods will tell you what your apoapsis is only the fly without having fly in the map view or even switch views at all. Also tells you your Delta V and TWR both during construction and in flight, which will pretty much determine if your rocket can even get to orbit at all.

So, lets start with the ascent path. The way I generally fly my rockets has served me well, as it pretty much applies to any rocket that should reasonably be able to fly, so presuming you've put together a good rocket, you can go to orbit using this sort of path.

The idea is to gradually go from straight up to lying on your side by the time you're ready to establish your orbit. As for how fast you do this, that largely depends on your rocket. Weaker rockets with a low TWR (Thrust to weight) will want to go more slowly and start the turn a bit higher than 100m/s. The reason for this is because weaker rockets will have to gather more vertical speed during the early portions of the flight compared to a more powerful rocket, and by the time you've gathered enough to not just fall back down into the atmosphere, your TWR will have raised enough to easily build up the horizontal speed needed.

A stronger rocket, ones that might have a TWR above 1.8 or so, will want to keep a slightly faster turn going, as they'll be building up a lot of vertical speed which can easily eat too much into your horizontal gains.

So what does all that gobbledygook mean to you, the beginner? Well, presuming your rocket can in fact make it to orbit if flown right, all you have to do is launch, wait till around 100m/s, and start turning left slowly. Good standard goals to hit is to have your rocket pointed at around 45 degrees (IE, halfway to fully horizontal) at about 30km up. For a beginner, once you hit this mark you can actually just stop turning and only continue pushing your rocket more horizontal if your prograde marker (The green circle) starts to get away from where your rocket is pointed. Doing this will continue pushing your apoapsis up until it hits whatever height your orbit you want to be. From there, you can cut your engines and coast to apoapsis, at which point you can burn to raise your periapsis, and thus establish orbit.

As for the rocket itself, we'd need to see what your rocket looks like. From there we can start suggesting things that'll help out. However, installing VOID or KER will ultimately prove more beneficial (both to you and us) as it will tell us exactly how powerful your rocket actually is.

In the current version of KSP, the amount of delta V needed to establish orbit is somewhere around 3500km/s. If the total delta V of your rocket doesn't go over this number you'll never to to orbit unless you run into some physics shenanigans. You'll also want each stage of your rocket to be over 1.0, and the first stage definitely needs to be at least 1.4. If your rocket has these stats, then your problem is how you fly. If it doesn't, its the rocket (and possibly how you fly )

[match]

Once you are launched, started your turn and confidence is high, switch to map mode and mouseover your apoapsis marker and it will show you "Time to Apoapsis". Better yet, left click it so it remains in view and you don't have to chase it with your mousie thingie.

If this ever reaches -0-, you are in a pickle, because you are no longer an up-goer, you are now a down-goer. Try to keep this time somewhere between 40 and 60 seconds by increasing and decreasing pitch. (Pitching up increases TtA; Down will decrease it.)

Switching

One problem with being in map mode is you can't stage, so watch your staging in the lower left and when you must stage, hit M, then space to stage, and then M again to go back into map mode. Complain on the forums that this is bad, like we all do

This is true, except that I have never complained about it, although it does chafe me considerably in the nether regions when I need to switch back and forth, from map view to pretty rocket view and I need to find and reclick the apoapsis to get the info needed to remain an up-goer...

I think I just complained about it... OK, 5th was completely accurate.

[Vanamonde]

Want to try my guide and example rocket?

[Der Anfang]

I usually just go straight up to 10-12 km before pitching into a 45° turning angle, depending on the load weight. Still, I would keep on turning very slowly toward the horizon. By 45 km, your velocity vector should be be just above or on the horizon. I would get the apsis between 70-90 km and make a node at the apsis. Burn at half the time it takes you to make a full burn when approaching a node. If a burn will take you one minute, you should be firing 30 sec before you actually hit the node.

Mech jeb is really fun, but also sorta lazy. I stopped using it in place of kerbal engineer because the delta-v is calculated more correctly, and there is more 'human' interaction with KER, but you get all the information you need. I would highly recommend that addon over mech jeb if you like to do things yourself. Plus, MJs auto pilot is fun, but it's messed things up plenty of times for me.

[JackBush]

Thanks, guys. I set the game on Easy and then tried Gavamonde's ship and guide and still couldn't get it. I run out of gas every time. So I'm giving up. I may come back to the game in a while but it's just gotten way too frustrating.

[Superfluous J]

Thanks, guys. I set the game on Easy and then tried Gavamonde's ship and guide and still couldn't get it. I run out of gas every time. So I'm giving up. I may come back to the game in a while but it's just gotten way too frustrating.

I can totally understand. This game has a very steep learning curve. Note: Easy mod is not any easier or harder than Hard mode when it comes to launching a single ship to orbit. Hard Mode just means you have to do more work to be able to afford and launch that ship.

I would suggest if you're frustrated and want to leave, to come back when 1.1 launches (sadly no release date yet) because there are some strong hints that there will be a new in-game hints/tutorial system that could really help you out.

[JackBush]

Thanks for understanding 5thHorseman. I'll watch for 1.1

[nekogod]

I know you've said you're giving up, but if you do give it another try, record the attempt and upload it somewhere, we may be able to see from the video where you're going wrong.

[RCgothic]

Heck, even a picture of your rocket should be enough to point out any major flaws.

[JackBush]

I came back to the game and am getting very close. I can get the ship there all right; now I'm having trouble with my orbit timing. If I have an estimated burn time of 8 seconds, what or how do I do it? Or: what is the timing for hitting "Z" to get into orbit?

This is the ship I'm using to do it.

- - - Updated - - -

That didn't work so well. Let's try this:

http://i.imgur.com/lL1KdQy.jpg

[GoSlash27]

- - - Updated - - -

That didn't work so well. Let's try this:

Edited September 29, 2015 by GoSlash27

[RCgothic]

A couple of observations to begin with:

1. The materials bay is heavy. You'll find it a lot easier to get into orbit without it, at least to begin with.

2. You also have too many engines in there. Whenever an engine isn't firing it's dead weight. And the staging apparatus is also unnecessary weight. Delete the engines and decouplers from stages 6 and 7. Merge the tanks that remain with stage 8 by attaching the lower tanks and engines to them. Each of those engines is easily capable of lifting two tanks with sufficient thrust left over to boost the central stack.

3. That central engine needs to be doing some work earlier or it's just dead weight. Select it within stage 4 and drag it into stage 8. It'll only burn 50% longer than the side attached boosters in this config, so give it an extra tank below the stage 3 decoupler.

4. At present you have a fairly long delay between an engine burning out, staging, and then re-igniting the engine of the next stage. This is because there's an enforced delay between staging to protect against accidental activation of a later stage. You also lose the control authority of the engine gimbal whilst it's deactivated and you lose speed. If you drag the engine from stage 2 into stage 3 it'll activate the engine immediately on staging, controlled by the throttle position. Other unnecessary delays have been removed by the other alterations.

5. Try attaching the side boosters higher up, which moves the centre of mass further forward and increases the control authority of your fins. If you can spare the parts for aerodynamic cones for the boosters, that'll help them punch through the air a bit too.

Note: The staging numbers will update through all the updates above, but I've referred to them by their original numbers for clarity.

Edited September 29, 2015 by RCgothic

[JackBush]

- - - Updated - - -

I'm afraid I'm not following. Do you mean the circularization burn?

Yes, that's what I mean. (I still haven't picked up on the proper terms.)

- - - Updated - - -

Hi again, 5th. I just clicked on your "Fundamentals" link and it looks good. I'll be looking at those shortly. BUT when I clicked on "New Horizons" I got an "Oops, no such place" message. Tried it twice; failed both times. Just so you know.

- - - Updated - - -

When performing a burn, you want to time it so half the burn is before the node and half is after. So, for your 8-second burn, you want to start at about T- 4s to the node, and therefore finish at T+ 4s.

Is there an ideal burn time to strive for. Maybe that's a noobish kind of question but thought I'd ask it. For example, do you try for a 30-second burn? More? Less? Less burns less fuel, doesn't it, so I guess there's that to consider.

[StormKat]

Is there an ideal burn time to strive for. Maybe that's a noobish kind of question but thought I'd ask it. For example, do you try for a 30-second burn? More? Less? Less burns less fuel, doesn't it, so I guess there's that to consider.

The lower the burn time the better. Hopefully the burn time is less than the total fuel amount you have. Nothing is more annoying than having 20 seconds of fuel when trying to perform a 30 second burn.

[GoSlash27]

Yes, that's what I mean. (I still haven't picked up on the proper terms.)

Jack Bush,

No problem at all. We've all got to start somewhere and you're coming along just fine.

I usually work it so that I keep the apoapsis 5-10 seconds ahead and adjust it with thrust. That way the apoapsis doesn't rise too much while I'm dumping energy into the orbit. Gives me a nice circular orbit without too much effort.

Best,

-Slashy

[Superfluous J]

Hi again, 5th. I just clicked on your "Fundamentals" link and it looks good. I'll be looking at those shortly. BUT when I clicked on "New Horizons" I got an "Oops, no such place" message. Tried it twice; failed both times. Just so you know.

Thanks! YouTube seems to be feeding me the incorrect url when I copy the link. I found the correct link and updated my signature. Here, have some rep

[hugseverycat]

Is there an ideal burn time to strive for. Maybe that's a noobish kind of question but thought I'd ask it. For example, do you try for a 30-second burn? More? Less? Less burns less fuel, doesn't it, so I guess there's that to consider.

Hi JackBush, I'm a pretty new player too. "Ideal" would be zero I guess?? I saw a video where someone's burn time was 4 seconds. But you don't need to aim for that now. You're just trying to get into orbit and you can do it inefficiently. My burn times are usually between 30 seconds and 2 minutes depending on what sort of monstrously heavy ridiculous thing I've built.

Your rocket looks like a it is carrying a lot of dead weight. Although creating massive rockets is the Kerbal Way, one lesson I learned recently is that sometimes less is more. Sometimes if a rocket doesn't seem to get to orbit, it's because it has too much fuel, not too little. The rocket I usually take up to orbit (with plenty of fuel to spare these days) looks like your long center one, with only two solid boosters (the mid-size ones). Here's a picture:

Yeah it's not the world's fanciest or best designed. I can see a lot of things I'd do differently. But it gets me there. My fuel tanks are 4 FL-T400s, 3 on the initial stage and the 4th up above. The solid boosters and the "swivel" engine fire on the same stage. My upper stage engine is a "terrier".

Basically what I do is enable SAS, throttle to max with Z, then fly up, tilting over gradually with an aim to be at 45 degrees when I'm at about 10km. After that I do keep turning over gently, but not too much. Dump those solid rocket boosters as soon as they are empty (it will happen fast). When I'm around 30km I switch up to map view and look for my apoapsis. Mouse over it, and just keep staring at it until it is above 70km (I usually go for about 80km) and then cut the engines with X.

Once I've cut the engines, then I set up the maneuver mode at apoapsis. You need to do this kind of quickly! Just click at apoapsis and pull your prograde marker (the green one without the X through it) until the apoapsis and the periapsis switch. You should then have a time to apoapsis and an estimated burn time. You'll also have that blue marker on the nav ball telling you which way to burn. Once you are above 70km, turn towards that blue marker, even if you have some time before your burn.

Basically you want to do half your burn before apoapsis and half afterwards. If you have some time before then, zoom out and you'll notice that your orbit probably isn't perfectly circular. I always overshoot a bit! You can pull the retrograde marker a bit to bring yourself closer to a circle. Then burn when your time to apoapsis is half of your total burn time.

I almost always run out of fuel on my launch stage during this burn, so if that stage is almost out of fuel, give yourself some more time because the terrier engine is less powerful but more efficient.

I know this is not the best way to get into orbit but even noobs can do it! You don't have to be perfect. Good luck!!

[Champ]

Here's my advice : don't try to get in a perfect 70x70km orbit. You are still learning : try to go to orbit, whatever the carasteristics of your orbit. Use a very simple rocket with far more fuel than you would really need : when learning, you are going to waste a lot of fuel. It's a normal thing. Dump anything that is not needed on your rocket (science items, etc). Then, when you know how to get to orbit, you can learn how to get in a specific orbit, and then you can learn to send usefull payload (with science) to orbit.

Also, when in the process of learning, dont try carreer mode.