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SkyHook

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I am trying to build a shuttle using B9 parts and FAR, and I need help! I have managed to build a shuttle that lifts of well at 80% throttle, but the weight imbalance caused by draining fuel is too much, and it eventually tips over, overwhelmed by the weight of the shuttle on its back. I have found a plugin that dynamically controls thrust (which may or may not be enough to stop the imbalance), but before I edit the config files of ALL of my engines, I wanted to turn to the community for advice. Has anybody successfully built a space shuttle in the NASA configuration? if so, what are you tips? Pics would be appreciated :)

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CoM, CoT, and CoL Markers

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The complete shuttle.

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The involuntary tip of death :/

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Edited by SkyHook
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I've rather easily built nasa-style space shuttles in the past (though I did cheat a little by putting ullage engines on the other side to keep it from flipping when the SRBs come off). I think what you could be doing wrong is putting an engine on the bottom of the big orange tank. That tank fuels the shuttle. Not it's own engine.

I would get a picture of mine, but I don't have or the .craft anymore.

Edited by mushroomman
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The main problem with NASA shuttles is that the centre of thrust does not go through the centre of mass. You have a massive shuttle perched on the side of a rocket. Also, I believe that the lift from your wings is causing some of that problem, creating a torque about the CoM.

Some space shuttle mods either use massively gimballing engines (out unless you want to create a new part or use those mods), or else point the engines away from the External Tank & SRB's (what I would suggest).

Edit: This is what I mean:

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If you're going for a straight up NASA launch, I would suggest following mushroomman's suggestion; omit the central engine.

Another question, have you tried launching the shuttle with cargo? How much does it tip then?

Edited by CalculusWarrior
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I usually do a similar thing by using an even number of EFTs. It doesn't count as NASA configuration any more, but it stops the CoM imbalance completely.

It should be noted that the Energia used its own engines to propel the Buran, although I suppose that isn't NASA configuration either.

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The only shuttle like thing I've made uses a pair of tanks, one on each side, perpendicular to the wings.

It still turns a bit, but it's controllable, and it's just due to small problems with the orbiter design that need ironing out.

I'm uncertain of the benefits of th NASA shuttle design, it seems strange to waste some thrust steering like that. Unless someone can explain why they decided to make it work as it did?

Edited by Tw1
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Maybe actually BUILDING it "In NASA Configuration" would help. [i mean, this WAS the most complicated build NASA did... so following specifications should yield far better results]

(TWRs are also much higher than they should be, especially at second stage (should be around 0.8)... and I still am wondering if you should be throttling the liquid engine that high during launch or saving most of that for second stage. [which would help persevere balance])

Additionally, you need control surfaces on the Shuttle, to lean the rocket back rather than gimbal it around. (And the SRBs should be gimbaled which AGAIN hurts launch)

*Point is to look up the specs rather than 'building it by your gut.'... although I do need to check it... I still feel that the main engines shouldn't come strongly into play until you breach the lower atmosphere (solving most of the "tipping" problems)

Edited by Fel
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They look cool, but I have mod that I download other day. I don't remember where it come from. Hope you dont mind I post 8 picture...

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why there's no picture of land? .... I crashed :-p I sucks with landing plane.

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Try using Damned Robotics. Put a powered hinge with you engines on it and use it to gimbal them. That way, you could move the CoT to the right direction.

EDIT : Deaf, it's Tyberdine Aerospace ^^

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Try using Damned Robotics. Put a powered hinge with you engines on it and use it to gimbal them. That way, you could move the CoT to the right direction.

EDIT : Deaf, it's Tyberdine Aerospace ^^

You beat me to it! LOL

I've been successfully launching space shuttles for months, using the method Netris describes. It takes some practice to learn how to manually gimbal engines while flying the ship, but it works very well.

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You beat me to it! LOL

I've been successfully launching space shuttles for months, using the method Netris describes. It takes some practice to learn how to manually gimbal engines while flying the ship, but it works very well.

The great owl offers his advice! I am an avid fan of your videos, so I know of the method, but wanted to use a more elegant option, but you can't argue with what works. Downloading now! I will post in the forum when/if I have success.

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You beat me to it! LOL

I've been successfully launching space shuttles for months, using the method Netris describes. It takes some practice to learn how to manually gimbal engines while flying the ship, but it works very well.

In fact, you've teached me everything I know on assymetrical thrust ^^ And one of my 2 shuttles in devellopement in inspired by you Eagle :)

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In the front view seems like a whale XD

Congrats skyhook.

I wanna to do a thread to talk all about shuttles, reusable ships to carry crew and cargo, with different approaches in the design. can we use this thread? or I make another one?

Maybe a new one with a more general tittle will be better.

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In the front view seems like a whale XD

Congrats skyhook.

I wanna to do a thread to talk all about shuttles, reusable ships to carry crew and cargo, with different approaches in the design. can we use this thread? or I make another one?

Maybe a new one with a more general tittle will be better.

You have my permission to use this thread to continue, I will see about changing the title to suit things better. Cheers!

Edited by SkyHook
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I would love to be able to do a "real" shuttle without a tank booster or odd horizontal engine somewhere. Most of my shuttle-like spaceplanes end up center-stack lifted on a traditional rocket (like the DreamChaser/DynaSoar).

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I think this is the third or fourth time I've posted this in various places...

Get the Damned Robotics mod. Attach a powered hinge or rotatron where you want the engine to go, set up two keys to rotate it (I use 7 and 8, but I have a really weird keyboard, so you might want something else), attach the engine. It takes some practice to manually control the gimbal through launch, but I think the added flexibility in building assymetric launch vehicles is worth it.

IMO, the stock hinge and rotatron are too fast for this job. I edited mine to make them turn significantly slower, like so:

// toggle parameters
rotateJoint = True
rotateAxis = 1, 0, 0
keyRotateSpeed = 6.0
rotateLimits = True
rotateMin = -60.0
rotateMax = 60.0
rotateLimitsRevertKey = False
jointSpring = 0
jointDamping = 0
onActivate = False
rotateKey = up
revRotateKey = down
fixedMesh = Base
servoName = New Hinge

Hell, I'll just go ahead and post a link to my whole channel, since this kind of launch vehicle is what I use almost exclusively nowadays: http://www.youtube.com/user/TheWinterOwl

Really, I kind of feel bad that this technique isn't more well known. I've been showing people exactly how to make it work for months.

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I was told that plugin only works for one engine at a time. Is that correct? Has it been fixed, maybe?

I would love to know this. Damned robotics got me into orbit, but if a plugin could handle the gimbal for me, that would be awesome.

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I would love to know this. Damned robotics got me into orbit, but if a plugin could handle the gimbal for me, that would be awesome.

Same here. The hinges are good... but they're also prone to glitches and bugs at unexpected moments.

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