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Mechjeb autoland is REALLY WIERD.


Zuni

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So I was moving a test base to another spot on kerbin. I hyperedited it into orbit, targeted the place and set it to land their. First it deorbits so it would land ~700km away from my spot. Then it hauls itself into orbit again Then it changes inclination to a near polar orbit so it could actually land there, and raises the apoapsis OVER where I was. Turned it into a highly elliptical orbit, tunes the inclination a bit AWAY from the spot and... Leaves. Just leaves me in orbit and sits there doing nothing.

WTF mechjeb!

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You guys always talk about how MechJeb is weird and such, but for me it always worked. I even put a tiny marker on the Mun to serve as some kind of landing pad. I copied its coordinates and inserted the in the autoland. It landed ON TOP of it. I tried twice with 2 different landers and it worked fine. After I landed I used the translatron to hover and move myself to where I wanted to. But the only thing strange that happened to me was when I try to execute a maneuver node that has some tweaks in the pink markers (you know, the ones that change the inclination of the orbit) is spins a little bit and then points correctly. But again that is very minor.

P.S.: Maybe your spacecraft a too complex? Try making something more symmetric and linear :)

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I usually just try again and it lands when I get some weird behaviour, never gave it more importance, but I'll try to send feedback when I get the "I'm not in a mood to land now" issue, I must warn that my save is already a troubled child... xD

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So I was moving a test base to another spot on kerbin. I hyperedited it into orbit, targeted the place and set it to land their. First it deorbits so it would land ~700km away from my spot. Then it hauls itself into orbit again Then it changes inclination to a near polar orbit so it could actually land there, and raises the apoapsis OVER where I was. Turned it into a highly elliptical orbit, tunes the inclination a bit AWAY from the spot and... Leaves. Just leaves me in orbit and sits there doing nothing.

WTF mechjeb!

Make sure you have the correct control point selected. If you choose something that faces in the opposite direction of thrust you will get no-where fast.

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No idea what HAL is

Fascinating! You must have just arrived on this planet, so allow me to be the first to welcome you. I'd suggest you start your tour of humanity's cultural archives by watching 2001: A Space Odyssey.

Anyway, while I don't really use Mechjeb I did experiment with it for a bit several months ago just to see if it lived up to the hype. I was never able to get the landing autopilot to work except on airless bodies like the Mun. Additionally, it's orbits were messy and it's attempts at docking laughable. As the old saying goes, if you want something done right, do it yourself.

Good luck though.

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Make sure you have the correct control point selected. If you choose something that faces in the opposite direction of thrust you will get no-where fast.

Anytime I have weird behavior with mechjeb its caused by my 'control from' direction not being set relative to my engines. Usually this is because I was docking and was steering relative to the docking port. For the autoland system mechjeb wants to end up pointed 'nose' up and assumes the net thrust vector is pointed down. If your engines are at an off angle or your COM is off center the autopilot will get confused.

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and Seinfeld sucks.

WHAAAA?!.. these pretzels.. ARE MAKING ME THIRSTY!!

lol.. for the sake of the topic at hand. Yea I found out MJ is wacked when it comes to landings. Last night I designate a target from orbit. MJ then instantly deorbits.. no where near the target. My trajectory drops to WELL within the atmosphere and MJ then decides to hover its way a hundred km killing nearly all my fuel. I had to shut it down and land there and then before I ran out.

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MechJeb when landing does 2 things pretty much :

1) While trying to land on the Mun, from an orbit it will send you out the Kerbin's gravity.

2) Try if you Lander can resist to a 500m/s landing.

it needs a bit of space to work its magic. Don't try to land from a 10km orbit. I usually give it 100km and never had trouble.

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Mechjeb landing worked great for me on most ships, landing within 1 meter of the desired coordinates, except for some reason it didn't calculate the thrust / weight ratio correctly on my skyscrane rover delivery vehicle and attempted the suicide burn about 4,000meters below where it should have.

Buzzed Aldrin

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One of the things that impresses me with Mechjeb is how you're plummeting towards the surface at 300m/s just a few km above the surface. Then MJ goes va banque on the burner and brings your shuttle to a stop at about 1cm above the surface.

When I try that it's going to be either one of two scenarios:

  • Lithobraking at 50m/s
  • Coming to a stop 1km above the surface

I now print out tables with what velocity I need at what altitude. But my safety margins are a wee bit bigger than MJ's.

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