Kerbin Landing Chart: Land at KSC consistently from your stations.

[alterbaron]

Update: New & Improved Chart!

Hi all,

Ever wanted to land at KSC reliably from low orbit? Then this is the chart for you!

NOTE: The x-axis is in units of 100,000 meters!

You must be more or less in a circular orbit before using the chart. Look up your orbital altitude on the x-axis. The corresponding y-coordinate gives you your "landing phase angle".

Basically, you want to burn so that your periapsis is at as close as possible to 0 meters, and at the given angle AHEAD of your target.

It's actually quite simple -- check out the example in the photo album.

Example Photo Album

Awesome Protip:

If you have a station in a fixed orbit, you could mark the relevant angles on a circle of paper, and use it again and again. That's really the way to go.

Let me know what you think!

Edited May 24, 2013 by alterbaron

[Scarecrow88]

Interesting chart, but most of my low orbits are below 200000m and the graph is difficult to read accurately from that distance and below.

[Francesco]

interesting, but could you do a scaled down version of this, covering just the 70-200 km range, so that we can see angles more accurately?

it's not like we're going to aerobrake from a 10000 km orbit that often

[alterbaron]

I updated the chart to cover the more useful range.

[Specialist290]

Nicely done This is one for the Drawing Board.

[Aviation Freak]

So as someone who is not very good at math, can this be broken down barney style please?

[Scarecrow88]

Thanks for making the changes, much more useful (for me anyway) at that range. All I need now is something that can measure the angles for me.

[Commander Zoom]

Much better (and quite useful), thanks!

[SpaceCowboy]

Yes, quite useful. If you can, I'd switch the x-axis to be logarithmic. That would make reading the values for low-altitude orbits way easier.

[Porspeler]

Thanks for your presentation! Very interesting, and a fun challenge.

I'm curious about the math behind the chart that you presented. How did you derive your graph? What equations did you use?

I'd like to be able to calculate reentries without relying upon a chart or mods.

[bwana]

thank you. i'm sorry for my curiosity but can you point me to the math that allowed you to derive this?

[Taki117]

So as someone who is not very good at math, can this be broken down barney style please?

Find your orbital altitude on the bottom of the graph (It's in multiples of 100,000m) then go to the part of the curve that is on the same line as your altitude. Then go Left to find the angle ahead of KSC that you need to put your periapsis.

[Behemoose]

Thanks for this! I've gotten pretty good at eyeballing it but it's nice to have exact numbers!

[StrandedonEarth]

I just use the Trajectories mod, great for pinpoint landings and aerobraking

[sewerbird]

Whoa, this is actually super handy! I've eyeballed for the longest time, but never quite pegged how much of a difference in phase angle is affected between a 75km station-to-KSC and a 100km station-KSC.

[THX1138]

Why not give the equations?

[Tank Buddy]

Very nice, but I just use the Trajectories mod.

[Superfluous J]

Cool graph. One suggestion, though: Change the horizontal labels to flat out km, and drop the "x10⁵m" part. "70km" is far more user friendly than "0.7x10⁵m"

[KerbMav]

Hm ... where would I put a keostationary space station and to which altitude would a undocking crew shuttle have to drop its PE to get into the vicinity of KSC?

[DocMoriarty]

Way too complicated for a Kerbal.

I use 2 simple return to KSC methods:

1. Fast (~200dV): do a burn above the desert part that comes before the continent where KSC is on so that the orbit line goes into water right where that big island East of KSC is. This will actually let you land close to if not at KSC.

2. Slow (~30-50dV): do a burn on opposite side of Kerbin of KSC and bring Pe down to 44000m just above KSC. This i use when my space plane's are nearly dry coming in.

Precise enough for my purposes, especially when using a space plane.