How can I disable atmosphere?

[Sharpy]

How can I disable atmosphere on Kerbin? (to test my Tylo lander)

I heard there were some hacks like this.

[Michael R]

Instead of suffocating all Kerbalkind, you could hyperedit your lander right to Tylo orbit for testing.

[GraviTykillz]

press alt f12 to bring up debug menu..they hack gravity

[Aaron Also]

press alt f12 to bring up debug menu..they hack gravity

This does not disable the atmosphere, while it does reduce gravity to, roughly, that of Gilly there is still atmospheric resistance. For a realistic testing scenario using Hyper Edit is probably the best approach, atleast that is what I do.

[TheDarkStar]

Aren't there atmosphere debug settings?

[Starwhip]

If you set all the drag sliders to zero it should "disable" the atmosphere.

Check the "Drag" section of the alt+f12 menu.

[Sharpy]

If you set all the drag sliders to zero it should "disable" the atmosphere.

Check the "Drag" section of the alt+f12 menu.

I'm much less concerned about drag, and much more about ISp of the engines. Achieving TWR>1 with the full payload, with the efficient, weak ones at the surface is my main purpose of this.

[Meithan]

I'm much less concerned about drag, and much more about ISp of the engines. Achieving TWR>1 with the full payload, with the efficient, weak ones at the surface is my main purpose of this.

If all you need is to make sure you can take off from Tylo, why not simply compute the Tylo-relative TWR? Tylo's surface gravity is 7.85 m/s². If you need to know if you have enough propellant to reach orbit, compute your ship's delta-v. Low Tylo orbit requires about 2300 m/s. You can just use your engines' listed vacuum values for thrust and Isp.

[Kuroki]

The very low-tech option is to put just enough SRBs on your lander to reach an apoapsis of about 15km on Kerbin and launch vertically.

Once your vertical velocity zeroes out at AP stage your lander normally. This should give you results within ~10% for ISP.