How to pick a landing spot on a planet with Atmosphere

[Elsig]

How do you land on a specific spot on a planet with atmosphere?

I can do it easily on any planet with no atmosphere since there's no drag. Where there's atmosphere however, it gets very difficult.

I've done it successfully on Duna (although I landed a few Km's away and had take off again to move closer to my base).

I've just tried to do it at Eve which was impossible. The dense atmosphere meant I either overshot or landed too early on all my attempts (i tried MANY times).

Any best practices on how to do it? Are there any tools/plug-ins to help with this?

[SiliconPyro]

I would really love to see the math to calculate that.

[Tiron]

How do you land on a specific spot on a planet with atmosphere?

I can do it easily on any planet with no atmosphere since there's no drag. Where there's atmosphere however, it gets very difficult.

I've done it successfully on Duna (although I landed a few Km's away and had take off again to move closer to my base).

I've just tried to do it at Eve which was impossible. The dense atmosphere meant I either overshot or landed too early on all my attempts (i tried MANY times).

Any best practices on how to do it? Are there any tools/plug-ins to help with this?

This is on the list of Mechjeb's many, many features. The landing module can calculate approximately where you'll come down based on your current course...or estimate your orbit after aerobraking if you're not coming down on the first pass. It's pretty accurate.

It also has an 'autoland' mode (it has autopilots for just about everything), but you can use just the prediction too.

[MBobrik]

No clue. On Duna, I can determine the landing spot by flying a few km above and triggering chutes, on Kerbin, I land on the KSP by repeating the same maneuver on the same from the same orbit that worked for me once. On Laythe or Eve I am just glad when I landed on the continent I intended to land on.

[Elsig]

This is on the list of Mechjeb's many, many features. The landing module can calculate approximately where you'll come down based on your current course...or estimate your orbit after aerobraking if you're not coming down on the first pass. It's pretty accurate.

It also has an 'autoland' mode (it has autopilots for just about everything), but you can use just the prediction too.

I didn't think of Mechjeb! I have it installed but only use it for Delta-V and for putting crafts in orbit around Kerbin (done that too many times now so happy to sit back and watch mechjeb do it).

Mechjeb worked a treat! I didn't use the autopilot but I picked a landing spot and burned manually. Had to do a few corrections on the way down but it worked! I hit my target almost spot on. I wanted to land on the ridge of a crater and it worked!

The developer of MechJeb is a genius, that must be some hefty maths going on in the background!

Cheers

PS! How do I change the post to [Answered]?

[stibbons]

I would really love to see the math to calculate that.

It's in the wiki! http://wiki.kerbalspaceprogram.com/wiki/Atmosphere#Drag

Although turning that in to a spreadsheet or incorporating it in to something like Kerbal Engineer would be pretty fantastic.

[durk]

I eyeball the approximate spot, come in steep and do a hard brake and follow up with chutes.

[SiliconPyro]

It's in the wiki! http://wiki.kerbalspaceprogram.com/wiki/Atmosphere#Drag

Although turning that in to a spreadsheet or incorporating it in to something like Kerbal Engineer would be pretty fantastic.

Yeah, that's going into my "KSP Math" spreadsheet, which I need to start organizing better. Or maybe I should just turn it into a Python script with a Tkinter GUI. That sounds like a fun project.

[haltux]

On Eve, I would suggest to try using a MK25 parachute. It is semi-deployed high and it does provide a very significant drag (4). My assumption (honestly, I have not actually tried it on Eve) is that with the thickness of Eve's atmosphere it should kill your horizontal velocity very quickly at a reasonably high altitude.

So you try to fly not too high (but no need to be very low either) over your target, and you open a MK25 a bit before reaching it.

Another option is to kill horizontal velocity with thrust, but of course it is a waste of fuel.

[bigmos]

eve is EVIL i have cratered many times. I finally am able to land but not take off

[Spyritdragon]

Should be possible. Are you comfortable working with integrals?