# [1.4+] BETA: Kerbal Attachment System (KAS) v1.0 Release Candidate 1

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6 hours ago, IgorZ said:

If you're talking about asteroids, then it's a "zero G situation", see above about the rules: winch only gives the initial momentum, it doesn't matter what it will do afterwards - something else has to negate the momentum. If you're talking about a real celestial body, then the vessel will be going towards the surface due to the G force of the celestial body, and you don't need a winch to make it happen

Just go to space, attach a winch to some vessel, start the motor and then immediately stop. You'll see that the vessel continues approaching, regardless to the fact that the winch motor is stopped. This is exactly what would happen if you were doing it in the real space.

Understood...once the the two vessels actually come in contact with each other and any slack is taken up the winch will encounter increased tension as it tries to pull the two craft even though they can't be pulled any further. Can you adjust the winch so it stops reeling in when the tension starts to increase?

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4 hours ago, Tyko said:

Understood...once the the two vessels actually come in contact with each other and any slack is taken up the winch will encounter increased tension as it tries to pull the two craft even though they can't be pulled any further. Can you adjust the winch so it stops reeling in when the tension starts to increase?

I'm afraid you understood it wrong. Again, the vessels collide not because of the winch pulls them together, but because of the object inertia. One vessel moves towards another vessel with some velocity, which, multiplied by its mass, gives the momentum. It doesn't matter how exactly the vessel got this velocity, what is important is the momentum which the vessel has when it touches another vessel. If the momentum is not zero, then you get a collision. The only way to prevent it is to apply a force in the opposite direction, but winch just cannot do that! I mean, it cannot do it in the physical world. In the game the winch, as a piece of code, can do anything.

Edited by IgorZ
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35 minutes ago, IgorZ said:

I'm afraid you understood it wrong. Again, the vessels collide not because of the winch pulls them together, but because of the object inertia. One vessel moves towards another vessel with some velocity, which, multiplied by its mass, gives the momentum. It doesn't matter how exactly the vessel got this velocity, what is important is the momentum which the vessel has when it touches another vessel. If the momentum is not zero, then you get a collision. The only way to prevent it is to apply a force in the opposite direction, but winch just cannot do that! I mean, it cannot do it in the physical world. In the game the winch, as a piece of code, can do anything.

LOL...thanks for the continued explanations...we are totally talking past each other. I understand how newtonian physics works and I know that the cable can only apply "thrust" in a pulling manner.

Challenge: Imagine you have a lander floating just a few meters above an asteroid. You're not using a Claw, but you want to make sure that lander doesn't move. You don't want a kerbal with a jetpack bumping your lander and sending it drifting off into space.

KAS Solution (I would think): You equip your lander with a couple of winches and harpoons. When you have the lander where you want it, you shoot the harpoons into the asteroid and then use the winches to pull the lander up against the asteroid. The winches give an initial tug and your craft descends under it's own momentum into contact with the asteroid. The winches are still running though, so once the craft touches the asteroid the tension on the winch cables is going to increase because it's trying to pull something that wont move any closer.

What I was trying to figure out is if there was a way to have the winches automatically stop when that tension on the cables increases.

Sorry if I'm not being clear. I hope this helps.

Edited by Tyko
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9 hours ago, Tyko said:

I understand how newtonian physics works and I know that the cable can only apply "thrust" in a pulling manner.

Phew! I started worrying at a moment. Glad we're on the same page here

9 hours ago, Tyko said:

Challenge: Imagine you have a lander floating just a few meters above an asteroid.

It a very good challenge. Not solved as of today IRL

9 hours ago, Tyko said:

KAS Solution (I would think): You equip your lander with a couple of winches and harpoons. When you have the lander where you want it, you shoot the harpoons into the asteroid and then use the winches to pull the lander up against the asteroid. The winches give an initial tug and your craft descends under it's own momentum into contact with the asteroid. The winches are still running though, so once the craft touches the asteroid the tension on the winch cables is going to increase because it's trying to pull something that wont move any closer.

Can be solved manually. Set the motor speed to the minimum (to reduce the impact energy), turn it on and wait till the vessel is almost touched the surface, then turn the motor off. Your vessel will hit the surface and bounce back, but due to the cable length is now shorter, it won't fly too far away. Then repeat this sequence until you have a full contact. What I also would suggest is having landing legs to damper the impact energy.

9 hours ago, Tyko said:

What I was trying to figure out is if there was a way to have the winches automatically stop when that tension on the cables increases.

With KSP 1.4 it's possible. They've updated the Unity version which now reports the force, that is applied to the joint (cable, in this case). In the previous versions I've tried to make something like this by calculating the force myself, but it worked ugly and unstable. My idea was (and still is) to achieve the following:

1. Change the electricity consumption depending on how much force the winch is applying. This is what happens IRL.
2. Limit the maximum power of the winch. Today it's limited by the cable strength, and it's awkward. Thу cable is usually by several orders of magnitude stronger than the motor power. I.e. it's far more likely that the winch will stuck than the cable get broken.

I never thought about your challenge, but having this feature implemented in general, it can be somehow controlled via the GUI. So that you could tell when the winch has to stop. However, I see a lot of caveats here. Due to descreete nature of the physics in Unity, many trivial things become very non-trivial. And cables is a very painful story. Note what happens with the winch head when you deploy it on Kerbin (vertically), that crazy twitching is a result of the discrete physics math.

Long story short, it can be done. But I decided to postpone this and some other cool features to the post-release improvements. The beta took too long already

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1 hour ago, IgorZ said:

Phew! I started worrying at a moment. Glad we're on the same page here

Long story short, it can be done. But I decided to postpone this and some other cool features to the post-release improvements. The beta took too long already

Thanks for working through that with me

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• 4 weeks later...

Just a short update. The next Beta version will be a release candidate. Which means, you'll be able to use it in your carrier games. The main upcoming changes are:

1. A new part: RTS (resource transfer station). It will allow you to do a flexible transfer of the the resources between the undocked vessels. It will also give you ability to dock the vessels, to achieve what the legacy winch was giving: a flexible link which allows moving the resources around. This part respects the "Resource Transfer Obeys Fuel Crossfeed" game settings, and you'll be able to transfer fuel when the game mode is enabled (in difference from the legacy 0.6.* version).
2. The harpoon, magnet and grapple hook will get their basic implementation. Do not expect them behaving in the same way as in the legacy KAS!
1. The harpoon will only be able to attach to an asteroid or  a celestial body. I won't be able to "hook" kerbals or parts anymore. And the harpoon will require an impact force to attach. It will require an EVA kerbal to detach. If you use it on an unmanned drone, the joint will be permanent.
2. The magnet will only attach to the parts. No impact momentum is needed, but the energy will be draining as long as the parts are kept together. The force of the attachment depends on the magnet strength, and the electricity consumption depends on the force that tries to pull the parts apart. On a good side: you can disable the link remotely by disabling the magnet electric power.
3. The grapple hook will attach on impact, and will allow the remote detachment. However, the attachment force will be much weaker, than for the other "hooks".
4. None of the parts will allow attaching to an EVA kerbal.
5. None of the parts will allow coupling with the target vessel.

The #1 feature will go live soon. The #2 will follow. Once all of them are tested, we'll go into the release.

Edited by IgorZ
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• 2 weeks later...

Guys, it's a free form poll. Below are 3 textured designs of a part. Some part. Don't ask me what it is and what's the purpose, vote for the look and make your guesses if you have an idea  Simple yes/no for the each version is what is needed. You can also vote for it on Patreon, where the voice has more weight and there are some details.

#1

#2

#3

Edited by IgorZ
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#3. Looks like a cable winch but weird to be textured that way and with gauges, so maybe instead some kind of flight data recorder thing? Can't see how that would apply to this mod tho so sticking with cable winch

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#3, too.
Perhaps it's a winch with integrated torque controller (smoothly accelerate, don't rip that cable) and scale.

Definitely #3

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#3!

Maybe the new RTS part that you mentioned earlier? Looks like a fuel hose to me...

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I like #3 because it has more gauges and they show different things.

I like #2 because gauge needles are bright blue (though both gauges seems to show the same measurement and there are only two of them).

I dislike the #1 because the colors are dull and the needle movement seems to be inverted (counter-clockwize).

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3 hours ago, snakeru said:

I like #3 because it has more gauges and they show different things.

I like #2 because gauge needles are bright blue (though both gauges seems to show the same measurement and there are only two of them).

I dislike the #1 because the colors are dull and the needle movement seems to be inverted (counter-clockwize).

Agreed.  #3 in #2's colours.  (I know, I know...this isn't one of the choices but I thought it'd be worth a try )

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I'd go for #3, but seriously consider whether whatever it is warrant high danger stripes. Still, no matter what it looks like, I'll love it.

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#3! Looks like a fueling system. Aren't those symbols the kind you see on fuel trucks?

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2 hours ago, Tyko said:

#3! Looks like a fueling system. Aren't those symbols the kind you see on fuel trucks?

actually, those are standard safety placards, the different numbers represent different types of danger and they can be used on any chemical container, although I think you're right, that looks like some sort of fuel hose reel to me.  I'm partial to the analogue gauges on #3.

Edited by Capt. Hunt
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The KSP 1.4.3 hold me back for a while, but I've finally completed the first release candidate!

# KAS v1.0.6713.41093

KAS v1.0 Beta 9 release:

• Add RTS-1 part - the resource transfer station.
• Many changes and improvements, incompatible to the beta8.
• This a release candidate! You can use it in the carrier games. Going forward, there will be a backwards compatibility between the beta builds.

YES! You can now use it in your main games. The future version will be backwards compatible, and your save files won't get broken. There are a lot of things to be fixed/changed/implemented before we can make the first release, but they all are either cosmetic or performance related.

Guys, I really hope you'll do an extensive testing of all the part in this build. It's too exhausted for me to manually click thru all the features in the every single part. To my best knowledge, they all should work fine (some questionable cases were checked). I'll let it be beta for another month, and then it'll become a release.

Edited by IgorZ
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I have been holding off upgrading while I finished my last mission in my current career game, and really hoped that I could use KAS 1 instead of 0.6 from the set out. Thank you for getting this up.

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I suspect that I need to remove KAS 0.6.4 before installing KAS RC 1.0.6713?

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I suspect that I need to remove KAS 0.6.4 before installing KAS RC 1.0.6713?

No, you don't have. They are independent. However, one day the old KAS will be deprecated, so the sooner you stop using it the better.

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@IgorZ I have 2 questions about the mod:

1. Does this have any parts from old KAS in it? When I use this I want to make sure that I don't have any parts on ships that will be deprecated.

2. Will this still work as a dependency (along with KIS) for mods like @Angel-125's Pathfinder mod?

Thanks

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On 5/22/2018 at 7:49 AM, RealKerbal3x said:

1. Does this have any parts from old KAS in it? When I use this I want to make sure that I don't have any parts on ships that will be deprecated.

The package named KAS-1.0 does't have any old parts. However, the models of many parts are the same between the old KAS and the new KAS, so it's easy to confuse. You have two options:

• Remove the old KAS altogether. It's not needed for the new KAS to work, and since you want only the new KAS, why would you keep the old one around?
• You can keep the both versions, but only use the parts from the "Kerbal Attachment Systmem" tab in the editor. This tabs is for the new KAs only.

Later, in the release,  all the old KAS parts will get prefix "OBSOLETE". This way you'll never confuse them.

On 5/22/2018 at 7:49 AM, RealKerbal3x said:

2. Will this still work as a dependency (along with KIS) for mods like @Angel-125's Pathfinder mod?

KIS is not affected in any way by this release. The mods that depend on the old KAS would need the old KAS installed in the game in order to work. There is no conflicts between the old and the new versions of KAS, so you can keep both to let the other mods working. However, in a long term, it would be highly desirable to migrate the other mods to the new version. I didn't push in this direction yet since I had no stable version.

Btw, to @all. It seems not many people tried to play with the new RTS1 part. Because I've figured out, the critical MM patch has missed the latest release, and the part is unusable   If you tried to use the part, failed, and chose to silently give up - don't! I'm making a new version (as promised, it will be compatible with the save files) which addresses this and several more issues.

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9 hours ago, IgorZ said:

The package named KAS-1.0 does't have any old parts. However, the models of many parts are the same between the old KAS and the new KAS, so it's easy to confuse. You have two options:

• Remove the old KAS altogether. It's not needed for the new KAS to work, and since you want only the new KAS, why would you keep the old one around?
• You can keep the both versions, but only use the parts from the "Kerbal Attachment Systmem" tab in the editor. This tabs is for the new KAs only.

Later, in the release,  all the old KAS parts will get prefix "OBSOLETE". This way you'll never confuse them.

KIS is not affected in any way by this release. The mods that depend on the old KAS would need the old KAS installed in the game in order to work. There is no conflicts between the old and the new versions of KAS, so you can keep both to let the other mods working. However, in a long term, it would be highly desirable to migrate the other mods to the new version. I didn't push in this direction yet since I had no stable version.

Btw, to @all. It seems not many people tried to play with the new RTS1 part. Because I've figured out, the critical MM patch has missed the latest release, and the part is unusable   If you tried to use the part, failed, and chose to silently give up - don't! I'm making a new version (as promised, it will be compatible with the save files) which addresses this and several more issues.

Ok, thanks! Great mod by the way!

OK, I have found a bug in this. If I try to attach two connector ports to each other with a tube the game stops allowing me to select any parts, or buildings if I return to the KSC. Additionally, many keybindings stop working. Weirdly, if I use the 'return to space centre' button above the altimeter, the ship still on the Island Airfield is reset. I have to restart KSP for it to work again.

Mods: 6 seat Mk3 Cockpit, DockRotate, Firespitter core, KER, KIS, KAS 1.0 (obviously), MM, Cormorant Aeronology, Trajectories.

Edited by RealKerbal3x
Bug!!!!!
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@IgorZ Congrats on the pre-release - I've finally decided to bite the bullet and update to 1.4.3 (from 1.3.1) and I might as well use this instead of the old KAS for the new career.

# Beta 10 (May 28th, 2018):

• [Fix] RTS-1 connector not being picked up by kerbal.
• [Fix] Multiple connectors of the different types are get focused at the same time.
• [Fix] On game load, the RTS-1 keeps a fixed hose length instead of the maximume allowed.
• [Fix] Winch could dock without creating a rigid joint between the port and the winch.
• [Fix] When winch docks with the attached vessel, it could be misaligned if the velocities are too different.
• [Change] New textures for RTS-1.
• [Change] Animate RTS-1 to make it more dynamic.
• [Change] Load restricted resources and fuel mixtures from the KAS settings. Can be adjusted by MM.
• [Change] Dramatically improve performance of the resource station GUI.