Is my way of orbit efficient

[War Criminal]

when i get into orbit i usually launch straight up until my apoapsis is around 100k and then i create a manuever and burn in that dirrection until im in orbit. i know this is not a regular orbit i just want to know if its efficient.

[Jupiter3927]

It's not very efficient.
Most players go straight up until the rocket isn't fighting air resistance then start turning.
I generally go up to 7.5km then turn to 45 degrees until my apoapsis is 70km+ then burn at the horizon until my apoapsis is 100-500km then do my orbital insertion manuever.

[Chibbity]

Going straight up, then going straight sideways is like walking two sides of a large field instead of crossing it diagonally. It's not efficient at all.

[Enorats]

I typically go straight up for a couple thousand meters, at which point I'm starting to hit the 200 m/s mark and air resistance starts to built up. At that point I want to start slowly dragging that prograde marker down so that I'm not screwed later in the flight - if you don't start a slow turn early on you'll find that you're unable to turn at all until you're way too high. You'll start going too fast in the vertical direction without being able to gain any speed horizontally.

Gravity turns should start off as slow turns and build to quicker turns around the 25-30km mark before slowing down again.. a couple degrees, a couple more, a couple more, 5 more, 10 more, 20 more, 30 more, slowly drop nose a few degrees at a time to reach desired altitude. That's how I do it.

[PolecatEZ]

You should start your curve as soon as possible (3km for lighter rockets, up to 10km for heavier ones). At 35km you should be going at or nearly horizontal. All you have to do is get your craft to around 2200m/s without losing altitude. Inertia will do the rest of the work.

[RoofCat]

Originally posted by Jupiter3927:

It's not very efficient.
Most players go straight up until the rocket isn't fighting air resistance then start turning.
I generally go up to 7.5km then turn to 45 degrees until my apoapsis is 70km+ then burn at the horizon until my apoapsis is 100-500km then do my orbital insertion manuever.

Seriously.

do Training - Going to orbit for better approach. Make it even slightlly shallower, turn sooner once you get the skills for building and flying proper ships. Training mission still has some safety buffer. Which makes sense for training. You can go considerably more aggressive to save even more fuel. Your main target is reaching orbital speed. Not climbing something. You stay up not because you are high enough. But because you "fly" (fall in fact) fast enough around it.

[Zorlond]

The only situation where just going straight up might actually be preferable is when you're running a mod like Remote Tech and you're launching an un-kerbaled probe without even a basic comms network in place. (which is what you'd need to to in order to just get a basic ccomms network in place to begin with) In which case the only way you'd keep control of the rocket is making sure it doesn't go over the horizon and lose connection to KSC, hence going straight up kinda makes sense.

The vast majority of your launches aren't going to be under those specific circumstances, though.

[Elementus]

That is the least efficient way to orbit, the time you start your gravity turn is different for each ship but generally you should turn 10 degrees to the east by the time you reach a speed of 100ms

[Pembroke]

The most efficient way is to:

- Always burn at either 100% or 0%

- Always go as fast as possible if no or very sparse atmosphere, or if denser atmosphere then at the max speed that optimizes the time gravity pulls you down vs. air resistance hindering your acceleration. This "gravity vs. air resistance" part can't be optimized fully except with computer aids but a good rule-of-thumb is to avoid getting the visual atmospheric effects that start to creep in at about the speed of sound and above.

- Make your gravity turns gradually. Ideal is to always burn prograde although that may not be possible 100% but strive for it.

- When you're circularizing burn at the closest point before apoapsis where your acceleration still, barely and only just, keeps pushing the apoapsis forward so that you just-and-just never reach it. Impossible in practice to get correct 100% when doing it manually but it's enough to simply do short burns very close to apoapsis so that you keep pushing it forward but not so close that you go over it.

Specifically note: If your rocket is going too fast the wrong answer is to turn down your burn slider. The correct answer is to realize that your rocket going too fast implies that you are not lifting enough! Essentially, your stage where the problem occurs has unutilized lifting capacity that you're simply throwing away and wasting in fighting the air resistance. So, add more useful stuff to the stages above, like fuel, until you get a more reasonable speed. You still get to orbit but you get there with more stuff.

[invision2212]

i usually go straight up to about 50 m/s then start tapping D and time it so by the time i reach 200 m/s im at 45 degrees and continue to keep it there until 900 m/s.

then turn it to 25 degrees and pull up the map and when it reaches 60k ill tip the rocket to 90 degrees and hold it there until 75k.

you should be around 1900 m/s at this point or so

now timewarp to 74k and low thrust to full orbit which should only take 10 real seconds or less from that point.

[edorward]

If you really want to see what the most effective launch profile looks like, install MechJeb and set up ascent guidance (or something like that). As Pembroke points out, finding the optimum balance between air resistance and gravity isn't something you can really do on your own, but the computer can calculate it and then project an icon onto the navball to show you what the most efficient path looks like for the specifics you program into it. Personally, I don't like that kind of thing intruding into my game (and I sure don't want the computer to do it for me), but making one launch with the path turned on will show you what you should be doing so you can do it on your own in the future.

[Purplefairy22]

My typical launch is like this:

• Thrust/Weight Ratio 1.3
• 60m/s turn 80 degrees East
• 250m/s 70 degrees
• 60 Degrees by 4000m speed around mach 1 (368m/s)
• ditch SRB's
• 15000m 50 degrees
• 25000m 40 degrees
• 30000m 30 degrees
• 35000m 20 degrees
• burn till apoapsis is 75000m
• ditch 2nd stage
• 3/4 of the circumference of kerbin has been covered
• Blow bubble with final stage.

i can easily fly an 18t rocket in career mode to minimus and the moon and back and still have plenty of delta V left

[RoofCat]

Originally posted by Purplefairy22:

My typical launch is like this:

• Thrust/Weight Ratio 1.3
• 60m/s turn 80 degrees East
• 250m/s 70 degrees
• 60 Degrees by 4000m speed around mach 1 (368m/s)
• ditch SRB's
• 15000m 50 degrees
• 25000m 40 degrees
• 30000m 30 degrees
• 35000m 20 degrees
• burn till apoapsis is 75000m
• ditch 2nd stage
• 3/4 of the circumference of kerbin has been covered
• Blow bubble with final stage.

i can easily fly an 18t rocket in career mode to minimus and the moon and back and still have plenty of delta V left

18t with SRB starting at TWR 1.3 up to 400m/s?
TWR 1.3 means initial acceleration of 3m/s². Which means you would need 100 sec to reach 300m/s. Since your TWR grows burning down fuel and turning east, you actually reach more in a shorter time. Still, Kickback burns for just 62 sec on default settings. Single Kickback also weights 24t.

So I guess it is rather your upper stage that has 18t?


Just got curious, because it is rather hard to build Mun lander within the initial career weight limits in my experience. Kerbin Orbiter - easy. Mun lander - would love to see. Probably doable with tiny probe and advanced small engines. Rapier-Nuke plane maybe?

[Purplefairy22]

Oh i never said i landed! Just close fly-bys one after another.
The whole craft weights 17.985t I haven't upgraded my launch pad. still puchasing the 90 research techs. got two so far.

I used Hammers to just get me clear of Light blue atmosphere.
i built a spreadsheet to calculate loads of ♥♥♥♥ for me. those hammers are at something silly like 37% thrust. They burn for ages.
My TWR throughout kerbin launch never exceeds 2.5. once your past 35000m the Isp is basically maxed on any rocket. and then you go for full burns.

[RoofCat]

Originally posted by Purplefairy22:

Oh i never said i landed! Just close fly-bys one after another.
The whole craft weights 17.985t I haven't upgraded my launch pad. still puchasing the 90 research techs. got two so far.

I used Hammers to just get me clear of Light blue atmosphere.
i built a spreadsheet to calculate loads of ♥♥♥♥ for me. those hammers are at something silly like 37% thrust. They burn for ages.
My TWR throughout kerbin launch never exceeds 2.5. once your past 35000m the Isp is basically maxed on any rocket. and then you go for full burns.

have you tried to go for full crazy Hammer boost to get 300+m/s asap and then sail at those 300m/s with full Lf+Ox? Should save even more fuel in theory, but may need small launch curve adjustment because you will stall a bit at those 300m/s right after Hammer stage - be careful to avoid nosedive.

The weird thing about Hammer though - it has less kN than Reliant and weights a lot. So it is kind of useless looking for least weight or best delta v in this size class. If you add two as boosters and go for vacuum stage right away ... still not sure. Rather not. Solid fuel has very low Isp. Which is direct link to low delta v for ships with limited mass.

Out of curiosity I actually designed less than 18t Mun lander. It requires some not as early parts though. Small Spark engines are medium tech for some reason.
http://steamcommunity.com/sharedfiles/filedetails/?id=1270438602

[dogwalker1]

I'm glad to see there isn't 100% consensus on exactly the right way to do it - but like the OP I am usually guilty of overly vertical launches, in no small part it seems because I neglect adding enough finage to turn the rocket in atmosphere. The above is all welcome info - any tips regarding fins (where & how much?) For a tall rocket do you put any on the upper part or just the bottom?