Good tips for orbit

[leosefcik]

So basically... i’m not new to the game. I have a hefty 200 hours on it already. I may seem like i know most basics of the game, and i do, but one thing i never knew really was getting to orbit. I have a basic understanding of delta-v and thrust to weight ratios and aerodynamics in this game, but every rocket i design just doesnt get the 4300 delta v to get into orbit. And if it does its because the rocket is very fuel consuming and just plain bad or i use hyperedit. This sucks because i still cant get my stages of the mun lander to orbit in career. While i dont have many problems with stability and i also have a basic and a bit ineffecient way to get into orbit, i have problems with getting just enough fuel and the right engines to get there. Any help or tips?

image of most effecient rocket i made for career (for getting to mun):

https://pasteboard.co/IirFkL5.jpg

the specs of the modded engine on the bottom (Kiwi engine from SpaceY):

https://pasteboard.co/IirG3PE.jpg

 

Edit: wait guys i just reached orbit with that rocket! It took many tries but i did. Does anyone havy any tips to make it better (or get a way better design overall)?

Edit 2: For those who the pasteboard doesnt work

https://imgur.com/a/sA8gH8W

Edited June 8, 2019 by leosefcik

[Harry Rhodan]

13 minutes ago, leosefcik said:

https://pasteboard.co/IirFkL5.jpg

https://pasteboard.co/IirG3PE.jpg

"Image not found"

[leosefcik]

9 minutes ago, Harry Rhodan said:

"Image not found"

Hmm... it works just fine for me.

[Harry Rhodan]

4 minutes ago, leosefcik said:

Hmm... it works just fine for me.

Did you set them to be publically visible? Otherwise you're the only one who can see them. You could also try to host them on imgur.com instead, they don't even have privacy settings as far as I know.

 

Edit: Works in Chrome. But please don't use your phone to make screenshots. Just press the print key and then paste the picture in any picture editor you'd ike to use.

Edited June 8, 2019 by Harry Rhodan

[bewing]

1 hour ago, Harry Rhodan said:

But please don't use your phone to make screenshots.

If he's on a console, he doesn't have a choice.

 

[leosefcik]

Just now, bewing said:

If he's on a console, he doesn't have a choice.

 

But does anyone have some tips?

[mystifeid]

59 minutes ago, leosefcik said:

But does anyone have some tips?

Try using some asparagus staging.

[Harry Rhodan]

1 hour ago, bewing said:

If he's on a console, he doesn't have a choice.

SpaceY parts, Mechjeb and KER on a console?

1 hour ago, leosefcik said:

But does anyone have some tips?

Yeah. Remove those part mods and try to build a simple rocket. Don't try to aim for Mun if you still don't know how to go to orbit. Set your delta V readout to vacuum because otherwise all the vacuum engines will give you much smaller numbers. Don't rely too much on SRBs.

Did you ever play the tutorials or watched a video explaining how to go to orbit by using a gravity turn  or do you just launch straight up and then try to gain orbital speed when you're high enough?

[Superfluous J]

Make sure your dV readout is for Vacuum and then click where it says the total ship's dV in the lower right of the VAB, right above the "reset" button. This will expand the dV readings of each stage. Then take a new screenshot.

Also, you shouldn't need 4300 m/s to reach orbit. You should need 3300-3500. Describe your ascent profile (what angle - roughly - you're tilted over at certain milestones like velocity or altitude or your apoapsis height) and we can probably help there.

Just looking at the pic, it seems you have WAY too much beef on the first stage. Those 2 SRBs along with your center engine are probably getting you 3-5x more TWR than you want at launch. You want TWR to be 1.3-1.6 at launch and I expect you may have 5 or more.

I agree with @Harry Rhodan though... walk before you can run. I don't care how many hours you have in the game if you can't get to orbit consistently your ship should have ONE goal: Get to orbit.

[Vanamonde]

Sounds like the problem is your ascent profile, which is a fancy term for when you make your turns from vertical to horizontal during ascent. As a rough guide,

1) I launch and go straight up to 100m/s, then pitch about 5 degrees east. 
2) I then switch to map view and watch my apoapsis marker climb. When it gets to 20,000 I start turning until I'm heading 45 degrees east and I hold that until apo reaches 60kms.
3) I then gradually turn to burning fully horizontal and hold that until apo reaches 80kms, which is where I usually orbit.
4) I then coast to about 15 seconds before hitting apo and burn horizontally until I've circularized.

Other players may have different plans and it may vary by ship design, but this should work for most ships. 

[Aegolius13]

The two tips above (ascent profile and higher-than-necessary TWR) seem like the big ones.  But a few other things: but if you use the Kickbacks or some other radial booster that gives you a ton of thrust, you might consider throttling down the middle stage as the boosters burn out and your thrust goes through the roof.  This will let your core stage burn longer after the boosters drop off.  Can also help if you're having stability problems from going too fast, too low.

Since we can see landing legs, at the top, I'm assuming there's a kind of lander-y thing exposed.  You might consider putting that in a fairing, which can improve both efficiency and stability (drag at front = flippiness).  

If you want more range after you get to space, I think you could use a similar design, but add another stage before the Terrier (maybe the Poodle).  Your Kiwi+Kickback first stage is a pretty good combo in terms of tapering down thrust as your rocket burns down, but the stepdown from Kiwi to Terrier is pretty big.  If you need to burn the hypothetical Poodle stage a bit before reaching orbit, no big deal.
 

A write-up I did a while back that you might find some ideas in:

 

[Superfluous J]

1 hour ago, Vanamonde said:

I then switch to map view and watch my apoapsis marker climb. When it gets to 20,000 I start turning until I'm heading 45 degrees east and I hold that until apo reaches 60kms.

If you've upgraded your tracking station enough, you can also click the orbit parameters tab in the lower left box, and have the info on the flight screen. This is nice because you can see when you need to stage, and stage when you see you need to.

[Zhetaan]

23 hours ago, Aegolius13 said:

The two tips above (ascent profile and higher-than-necessary TWR) seem like the big ones.  But a few other things: but if you use the Kickbacks or some other radial booster that gives you a ton of thrust, you might consider throttling down the middle stage as the boosters burn out and your thrust goes through the roof.  This will let your core stage burn longer after the boosters drop off.  Can also help if you're having stability problems from going too fast, too low.

@leosefcik:  To the above I add that you can also use the thrust limiters on the Kickbacks to slow their burn rate.  If you have 4,300 m/s of delta-V, then fuel is not your problem.  Your choice of engine and ascent profile are the issue.

Be mindful, however, that if you do decide to change engines, then you may create a fuel problem:  A fuel load that lets a Terrier run for ten minutes will supply a Vector for a lot less time.

[Kryxal]

Consider using steerable winglets on the boosters and moving the first liquid stage off the initial part.  You may need a more aggressive gravity turn than advised above, I can't tell your TWR initially.  If you're passing 45 degrees at 10-12 km up, you're probably good.

[Socraticat]

I use the longer tanks to save parts count and stability. I also only put wings in a 4x symmetry around the center stage, near the bottom.

The last tip I heard, and love, is to tie your outer stages together at the bottom. If your center stage is burning when you decouple the kickers, you have a nice ICBM middle stage.

[Hoozemans]

Another tip that's been of much use when I first started:

Build your rockets top-down, starting at the last stage, and adding each prior stage to the bottom, keeping an eye on the total dV.

- For a simple 90km-orbit-and-return mission, start with the part that actually gets to orbit: give it just enough dV to return from orbit, say about 100 m/s. TWR doesn't matter at this stage, just dV.

- Then start building the stage below that: give it just enough oomph for a final kick into orbit, assuming you've gotten your apoapsis up to 90 km with a surface speed of some 2200m/s: the circularization burn. If you do your gravity turn right, that's somewhere around 1000 m/s. Again, TWR isn't really important at this stage, as long as you can apply the final 1000m/s before you re-enter atmosphere.

- Then you build the part that actually gets your apoapsis up to 90km, and delivers that first all-important 2200m/s surface speed. At this stage, TWR is, naturally very important. If you've got powerful engines (eg. Mainsails), use them. If you don't, keep strapping on boosters until you've got that 2200 m/s

And then it's just a matter of using all that dV in a more or less efficient way: start turning to the east as soon as your vertical speed exceeds 100m/s - but don't turn too fast: you're aiming for an angle of approx 45 degrees at 10000 metres. At 30000 metres you should be a few degrees from horizontal. Keep an eye on your apoapsis and periapsis while doing your turn: you don't want to reach your apoapsis too fast, not before you've gotten your periapsis as high as possible: that way, you can have a relatively short circularization burn, and aren't risking re-entry before you get to deliver the final m/s. O, and don't worry about details like max Q or friction: KSP is quite forgiving, and it's easier to just give your rocket a few more m/s of dV than to fine tune your ascent to deal with them.

Anyway, that's how I got started. Took me a few launches before I had anything that didn't simply fall apart before getting up to a decent speed, mind you.