2 questions

[Cannon]

1.when i want to go to mun for example and it's on the left side of my ship, if i burn just vertically I'll get an encounter 100%.

Now my question is why is everyone making the orbit first, vertical flight seems much more easier and efficient?

2.how do i calculate the efficiency of rocket, i mean which engine will fit best with some barrels?

And btw, What's the difference between 0.24 and 0.24.2.

[Red Iron Crown]

1. It has to be timed perfectly for that to work.

2. The rocket equation. Learn how it works and your rockets get much better.

0.24.2 fixed some bugs from 0.24/0.24.1.

[Cannon]

1. It has to be timed perfectly for that to work.

2. The rocket equation. Learn how it works and your rockets get much better.

0.24.2 fixed some bugs from 0.24/0.24.1.

Thanks, can you tell me which bugs if you know

[Red Iron Crown]

0.24.1 release notes.

0.24.2 release notes.

[Taki117]

to answer your first question most people get into orbit first so that they can not only pick their landing spot, but also can control their descent better. Since the Mun is rotating underneath you (even if it is only 9m/s) if you just went straight for landing not only are you having to burn off hundreds (if not thousands) of m/s of dV, but also where you want to land is going to change as well.

This leads into your second question. Rocket efficiency is determined by the Rocket Equation. (Which Red Iron Crown was nice enough to link) the main determining factors are the weight of your ship that isn't fuel, and the efficiency of your engine. The more efficient the engine, or the more of your ship that is fuel, the more delta-V you have (commonly abbreviated dV) Now, dV is how much you can change your velocity. i.e it takes approximately 900m/s of dV to get to the Mun. This means that if you execute your maneuver at periapsis to raise your apoapsis out to Munar orbit you will add 900m/s to your orbital velocity.

This does not mean that you are always adding velocity. If you take the same example and reverse it, if you wanted to bring your apoapsis back down, you would subtract the 900m/s from your orbital velocity. Although, this too is an oversimplification in that if we wanted to change planes, or change both apoapsis and periapsis at the same time, our orbital velocity at the current point in our orbit might not change at all.

To put it in the simplest of terms dV is nothing more than how much you can change your ships orbit by.

[Javster]

My rule of thumb is that the Mun has to be 45 degrees ahead of my spacecraft.

[michaelhester07]

Going to orbit first lets you plan your burn to get to the Mun. This is a skill you need for farther away targets.

If you go to the map (M) and click on your path in blue you get an option "Add maneuver". This lets you plan a burn. Proper planning can save you fuel in the end. Orbiting Mun also lets you chose a landing spot so instead of hoping to get a flat spot where you won't roll your ship when you land on it you can land safely and get back to kerbin.

2: The rocket equation (see above posts for links). If you don't want to do all that math in your head or in Excel I suggest getting a mod like Kerbal Engineer or MechJeb. These will calculate your efficiency for you and relay the most important information you need: Delta V. They also give you other stats, like per-stage dV, Thrust to Weight ratio, the mass of your ship, the atmospheric drag it has, etc.

DeltaV is how much velocity change your craft can produce. When you plan a maneuver you see the maneuver's cost in this number. What you don't seein stock KSP is how much deltaV you have left on your ship. If there is any mod I want Squad to incorporate it's a deltaV calculator. It *is* rocket science after all. The higher you get your DeltaV the more efficient your rocket is (in layman's terms. there is more that effects efficiency, like Thrust to weight ratio).

[Redshift OTF]

I tend to use Kerbal Engineer or MechJeb to show what DeltaV and TWR ratio my stages have. I would hate to build something cool that wasn't functional.

[Cannon]

My rule of thumb is that the Mun has to be 45 degrees ahead of my spacecraft.

exactly ;D!

[mhoram]

i mean which engine will fit best with some barrels?

This thread is very helpful for your question:

Mass-optimal engine type vs delta-V, payload, and min TWR.

[KerikBalm]

They go to orbit first to reduce lost dV due to gravity drag.

It is more efficient to burn perpendicular to the force of gravity, than opposing it