r4m0n

[PART, 1.0.2] Anatid Robotics / MuMech - MechJeb - Autopilot - Historical thread

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Sure. Use the Ascent Autopilot to fly up to something in orbit. Once you get close (>10 km), use the rendezvous module to null out relative velocity (RVEL-), then burn towards the ship (TGT+). Rinse and repeat until you get close.

Btw, r4m0n, another bug report in this regard: MechJeb ascent autopilot's 'wait for LPe" thing does not work on the Mun. Regardless of which spacecraft I choose to rendezvous with in orbit, it consistently just fires me off as soon as I hit the Engage button. Any thoughts?

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Sure. Use the Ascent Autopilot to fly up to something in orbit. Once you get close (>10 km), use the rendezvous module to null out relative velocity (RVEL-), then burn towards the ship (TGT+). Rinse and repeat until you get close.

Btw, r4m0n, another bug report in this regard: MechJeb ascent autopilot's 'wait for LPe" thing does not work on the Mun. Regardless of which spacecraft I choose to rendezvous with in orbit, it consistently just fires me off as soon as I hit the Engage button. Any thoughts?

There's a rendezvous module? How do I access it, it's not on the mechjeb controls.

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There's a rendezvous module? How do I access it, it's not on the mechjeb controls.

If it's not, you aren't using the latest version (1.9.1). It was removed in 1.9 because KSP 0.16 broke it badly, and re-added in 1.9.1 after fixing.

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Sure. Use the Ascent Autopilot to fly up to something in orbit. Once you get close (>10 km), use the rendezvous module to null out relative velocity (RVEL-), then burn towards the ship (TGT+). Rinse and repeat until you get close.

Btw, r4m0n, another bug report in this regard: MechJeb ascent autopilot's 'wait for LPe" thing does not work on the Mun. Regardless of which spacecraft I choose to rendezvous with in orbit, it consistently just fires me off as soon as I hit the Engage button. Any thoughts?

I'm guessing the launch to rendezvous function only works in the initial launch, I'll take a look at it.

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I can confirm that TGT+ fails if you're close to target, it even shows that in the steering error.

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Yes, .13 doesn't have the plugin system. The Demo is great, but buy the full game before it gets more expensive. .17 will have new planets and you can use plugins if you buy today.

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Maybe a n00b-question, but is there a way to get into a POLAR Orbit around Mun, using Mechjeb? I can't figure it out...

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Sure. Get into any orbit around the mun, then use SmartA.S.S. to point you at NML+ or NML-, and burn until your inclination is as high as you want it. (90 degrees is exactly polar, but 89.9 is close enough for most applications)

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I can confirm that TGT+ fails if you're close to target, it even shows that in the steering error.

Luckily your navball is correct at this point. That's what I use.

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Yeah, it's good to know how to do it manually even if you have an autopilot, saved my mission so often already.

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i have suggested the idea of a flight director mode, so that you can see what the AP would have you do but still be in full authority to control the ship as you see most fit

it's somewhat unreasonable to expect any autopilot, no matter how advanced will be able to handle the most over-the-top behemoths we enjoy throwing so casually upon them - there are many cases (poor designs, i'll admit) where anything besides manual control is a death warrant for the brave few kerbals aboard and fleeing thousands below

so then, a flight director offers a best-of-both worlds solution - it tells you how to fly the beast as per the flight path defined for ascent/landing, or to point the ship when you select radial+/- (it's not always straight up/down) - but it leaves you up in command so you do what needs to be done in order to get there

of course, this is more critical when dealing with the ascent phase.... the unstable nature of lower stages makes AP a very skittish device more prone to killing you than not - but on the other side at many times, flying by hand is simply more fun, is it not? :)

cheers!

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@1of6billion

Just get into a regular munar orbit, then use the smartass and orient yourself to nml+ or nml- and thrust untill you've achieved polar orbit. There is a readout somewhere named "Orbital inclination" if that indicates +90 or -90 degrees you're in a perfect polar orbit. You could attempt to aim at the pole on your approach but this method is far simpler.

Edited by willow

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I'm trying to control debris with 1.9.1, but I can't get the mechjeb interface to show up or right click to control parts (although I can still burn). Is it normal or is my mechjeb buggy?

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... Because it doesn't matter which way 'up' the rocket is. It's probably more aerodynamically stable upside down or something, since the ascent autopilot just tries to keep it from rolling very much.

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@1of6billion

Just get into a regular munar orbit, then use the smartass and orient yourself to nml+ or nml- and thrust untill you've achieved polar orbit. There is a readout somewhere named "Orbital inclination" if that indicates +90 or -90 degrees you're in a perfect polar orbit. You could attempt to aim at the pole on your approach but this method is far simpler.

Thanks! Got it! Ran out of fuel @ 80° ;)

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Yeah, the fuel problem can be overcome by burning towards the Mun where you're basically going to stop in front of it (and have a collision course with the surface) and then when you're in the Mun's SoI you can burn north or south to get a Polar orbit.

I might jump into KSP real quick and grab some screenshots so you can see.

EDIT: here it is, my Polar Mun Orbit Guide: http://imgur.com/a/2kxRa#0 enjoy!

Edited by Ekku Zakku

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Alright, I hope somebody can help me with this. I know that the Rendezvous module is more of a gimmick than a major part of MechJeb, but...alright, here's the question:

Until recently, I could easily "dock" two small ships using the pro/retrograde, tgt and rvel functions of MechJeb. It wasn't actually docking, but I got the noses together. Now that a mod has implemented actual docking, it doesn't work anymore, for some reason.

When I use the tgt mode at a distance of about 20m, the nose of the active ship points god knows where but certainly not towards the target ship. So I try to just point the target in the retrograde orientation and the active vessel prograde. But as soon as I switch vessels, the target starts to slowly reel and seconds later doesn't point retrograde anymore.

I know for a fact that both of those functions worked fine a while ago. I used them. Does anyone have a clue why those two functions are suddenly acting up for me?

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TGT+ is bugged, and MechJeb only controls the active ship.

For docking it's better to use the ORDA computer, as it doesn't have these issues. You can use it with erkle's mod too (probably limited though).

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For docking it's better to use the ORDA computer, as it doesn't have these issues. You can use it with erkle's mod too (probably limited though).

The ORDA computer requires that the ORDA docking ports are attached to the craft. If you use it with Erkle's mod, you would have to put the Erkle docking ports over the ORDA ones. Not sure how that will go down...

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