Surface or Orbit Navball on launch

[rolinger56]

Hey Kerbal fans!

I have a newb question here.  I was playing KSP yesterday and I was practicing my Gravity Turn.  I noticed that whenever I launched my navball was set to surface mode.  Should I have it set to orbital mode instead? Also at some point during the ascent my navball switches to orbit and moves my prograde marker over many degrees which causes my rocket to move dramatically.  It is making me wonder if I should have the navball set to orbital mode in the first place.

 

Thanks and happy flying to you all!

[Vanamonde]

Those settings are merely intended to be guidance. You can switch it or not as is helpful to you. There is no "right" answer.

[antipro]

7 hours ago, rolinger56 said:

Should I have it set to orbital mode instead?

no, it switch automatically, like you said.

 

7 hours ago, rolinger56 said:

at some point during the ascent my navball switches to orbit and moves my prograde marker over many degrees which causes my rocket to move dramatically.

to avoid the rocket moving following prograde marker you can:
- stop point at prograde marker but use SAS only or
- use a mod like MJ or Gravity turn.


https://wiki.kerbalspaceprogram.com/wiki/Navball#Point_of_reference

As all movement in space is relative, the point of reference determines the object from which all distance measurements and velocity vectors are made. Clicking this area will toggle the point of reference between Surface, and Orbit, and Target. Target mode is only available if a target is selected.

To land on the surface of a planet or other celestial body, it is important to have the reference set to Surface to account for the rotation of the celestial body. For orbital maneuvers (i.e., not landing), the planet's rotation is unimportant, except in the case of a synchronous orbit, in which case the point of reference should be set to Orbit, which is like Surface but without accounting for the planet's rotation.

 

7 hours ago, rolinger56 said:

It is making me wonder if I should have the navball set to orbital mode in the first place.

no, don't switch to orbit, let the ship to follow the marker when it changes or just use SAS only.
The aerodynamics will keep you in the correct direction until you want to change.


again

On 3/13/2014 at 11:48 PM, adinfinitum said:

It just changes the frame of reference that your velocity is determined from. Surface mode shows you your velocity relative to the surface of the body you are orbiting, while orbit mode calculates it relative to the center of the body you are orbiting.

Because all the planets and moons rotate, you have a non-zero orbital velocity when you are stationary on the surface. On the surface of Kerbin, you are moving about 175 m/s relative to the center. If you switch the mode from surface to orbit while on the launch pad, it'll show you that velocity. Because that eastward motion shows up in orbit mode but not in surface mode, the markers showing your heading will change slightly when switching between the modes.

Target mode does something similar, it just sets your target as the reference point for calculating velocity. And if you forget to switch from orbit to surface when landing, you're gonna have a bad time.

Edited September 23, 2021 by antipro

[jimmymcgoochie]

If the navball switching from surface to orbit causes a large change in pitch when you’re following the prograde marker, you’re pitching too little and/or too slowly. Try pitching over a bit more steeply or at a lower speed/altitude; I tend to pitch 5-10 degrees at 50m/s depending on the TWR, with a higher TWR necessitating a faster pitch. Try to keep your time to apoapsis between 30 and 50 seconds, pitching up/down or adjusting throttle as necessary.

On the topic of TWR, it’s usually best to go for 1.4 to 1.8 on the launchpad- too low and gravity losses eat into your delta-V, too high and you’ll get more drag losses plus the extra weight of those high thrust engines reduced your delta-V too.

There are a few mods that can automate gravity turns and launches- GravityTurn is a pretty simple one to use but often requires multiple attempts to get the curve right, while MechJeb does many things besides just launches and can be very useful, but the options can be a bit bewildering. It might help to use one of them and watch what they do then copy them yourself to understand how to make a good gravity turn.

[AtomicTech]

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