Kerbal Attachment System (KAS)

Allows linking separate vessels without cooking them for the purposes of towing, lifting or resources transfer.

License: Public Domain

Game Version: 1.12.3

Source code: ihsoft/KAS

Downloads: 301,160

Author: ihsoft

Mod Website: Forum Thread

Support this mod: Donate

Followers: 408

Outdated Mod

This mod is not known to work with the latest version of Kerbal Space Program. Proceed with caution.

Information Changelog Stats

Kerbal Attachment System (KAS)

This mod is another extension to the EVA duty of the kerbonauts. Now they can link different vessels together. Why linking? Well, how about transferring resources without docking? Or maybe two vessels need to stay together while not docked. Even more, this mod has active parts that can work as winches!

A great variety of links is supported:

  • Rigid. It's basically a simple strut, but kerbals can set it up or remove being EVA. Bring some of these things on your Mun base and reinforce the structure!
  • Rigid unlocked. It's still the same strut, but the joints are unlocked. It allows the vessels to move, while not getting too close or too far to/from each other.
  • Active rigid. Do you need to tow a vessel? If yes, then you need a tow bar. Only in KAS you can find advanced models of tow bars that can assist steering. Greater towing speed means more fun!
  • Flexible. It's an elastic cable that can stretch at some extent while still forcing the vessel to stay together.
  • Active flexible. It's still a cable, but now its distance can be changed either via an EVA kerbal, or via a remote control GUI. Basically, it's an electric winch.
  • Resource transfer. Zero structure force in exchange to an ability to have some free length. Link the vessels up to the maximum distance and move the resources via a convenient GUI (a way more convenient than the stock one!).

Almost any type allows remotely docking the vessels. Once docked, the vessels become a single base where the stock game functionality can work.

Demo media

* The videos above were created using the pre-release versions of KAS. Real appearance can differ.

Languages supported

Русский Русский

Italiano Italiano

Español Español

简体中文 简体中文

Português Português

Français Français


You can support this and the other of my mods on Patreon. This is where I post my ideas, prototypes and the features development progress.

Other useful mods for EVA

If you want doing EVA comfortably, you really should consider adding these mods as well:

How to install

  • Recommended:
    • Install and run CKAN.
    • Search for "Kerbal Attachment System" or just "KAS", then install the mod.
    • Occasionally run CKAN client to update KAS (and other mods) to the latest version.
    • If you follow this path, then all the KAS dependencies will be updated automatically. It may save you a lot of time during the update.
  • Manual:
    • Download the ZIP archive:
    • If you have an older version of the mod in your game, you must delete all the old files first! Do not just copy over, this will likely result in compatibility issues.
    • Unzip the release archive into the game's GameData folder.
      • Note, that names of the folders must be exactly like in the archive or the mod won't work.
      • The release archive contains the minimum versions of the required dependencies: ModuleManager and CommunityCatgeoryKit. If your game has better versions, do not overwrite!
    • Verify the installation: the mod's file must be located at <game root>/GameData/KAS/


Ask questions and propose suggestions on the forum.

Version 1.12 for Kerbal Space Program 1.12.3

Released on 2022-09-08

1.12 (September 7th, 2022):

  • [Fix] Set a proper normal texture to the RTS hose.

Download (3.07 MiB)

Version 1.11 for Kerbal Space Program 1.12.3

Released on 2022-06-04

1.11 (June 3rd, 2022):

  • [Enhancement #329] Bring back haroon and grapling hook.

Download (2.98 MiB)

Version 1.10 for Kerbal Space Program 1.12.2

Released on 2021-10-21

1.10 (October 20th, 2021):

  • [Fix #326] Error in the logs when an inactive vessel gets in range.

Download (2.82 MiB)

Version 1.9 for Kerbal Space Program 1.12.1

Released on 2021-07-02

1.9 (July 1st, 2021):

  • [Fix #324] Resources intermittently disappear from RTS transfer dialog.

Download (2.82 MiB)

Version 1.8 for Kerbal Space Program 1.12.0

Released on 2021-06-28

1.8 (June 27th, 2021):

  • [NOTICE] If a connected KAS part gets involved in a stock EVA construction operation, it will get immediately detached from the peer. To avoid unpexected behvior, it's recommended to manually break the link before using EVA construction mode.
  • [NOTICE] The interactive links (like in PCB) are now not possible in EVA construction mode.
  • [Compatibility] Drop AVC version check due to the KSP 1.12 duplicated mods handling bug.
  • [Change] Better detect if any of the peers in the KAS connection got destroyed for any reason. The link gets properly broken in this case.
  • [Enhancement] Allow attaching to the winches surface to let reinforcing them with struts.
  • [Enhancement] Don't show resources that cannot be transferred in the RTS GUI.
  • [Enhancement] Allow disabling the controls hints in the RTS resource transfer dialog. Use setting showTransferDialogHints.
  • [Enhancement] Allow disabling the controls hints in the winches remote control dialog. Use setting showRemoteControlDialogHints.
  • [Enhancement #248] Add ability to scale Transfer GUI.
  • [Enhancement #321] Scale the Winch GUI dialog.
  • [Fix #302] GUI does not respect hide/show function.
  • [Fix #306] Logs spam from the parts dropped on the ground.
  • [Fix #307] Interactive attach mode conflicts with construction mode.
  • [Fix #308] Linked parts can be dragged in construct mode.
  • [Fix #309] TJ parts cannot align when pulled out of cargo.
  • [Fix #311] Breaks the Asteroid Redirect Training Mission.
  • [Fix #313] Coupling vessels via the rigid link cause vessel breakage.
  • [Fix #314] Retract cable option is visible when the connector is locked.
  • [Fix #315] Attaching KAS links resets EVA editor parts highlighting.
  • [Fix #316] The detached physicsless parts stay physicsless.
  • [Fix #317] Coupling role delegation doesn't work.
  • [Fix #318] EVA construction mode highlighting stays on the KAS pipes after the mode is canceled.
  • [Fix #320] Renderer is active even on the locked winch connector.

Download (2.82 MiB)

Version 1.7 for Kerbal Space Program 1.10.1

Released on 2020-07-31

1.7 (July 30th, 2020):

  • [Change] Better react on the attached part(s) destruction to properly reset the link state.
  • [Change] Some performance improvement for the winch connector handling.
  • [Change] Update EN/RU localizations to version 6.
  • [Change] Update Chinese localization.
  • [Fix #295] Stop using MiniAVC.dll in favor of MiniAVC-V2.dll.
  • [Fix #297] Decoupling near winch connected in editor causes the winch to break in to two separate vessels.

Download (2.83 MiB)

Version 1.6 for Kerbal Space Program 1.9.1

Released on 2020-04-27

1.6 (April 26th, 2020):

  • [Fix #289] RTS-1 docking mode is not reset on decoupling.
  • [Change] Stop complaining about KSP minor version change.
  • [Enhancement] Add two new localization strings for the custom corridors: Corridor-1000 and Corridor-1500.
  • [Enhancement] Add an optional patch MM-LegacyKASPipesPart.txt to simulate the old KAS pipes. Use at your own risk!

Download (2.83 MiB)

Version 1.5 for Kerbal Space Program 1.8.1

Released on 2019-10-28

1.5 (October 27th, 2019):

  • [Change] KSP 1.8 compatibility. WARNING: the mod won't work with version lower than KSP 1.8!
  • [Enhancement] Add Chinese localization.
  • [Fix #279] Can't surface attach the hw-80 winch.

Download (2.83 MiB)

Version 1.4 for Kerbal Space Program 1.7.3

Released on 2019-06-08

1.4 (June 7th, 2019):

  • [Change] Update ES-ES localization.
  • [Enhancement] Use icon of better resolution in the editor to avoid bluring.
  • [Fix #271] KSP 1.7.1 breaks grabbing connectors from winch type parts.

Download (2.82 MiB)

Version 1.3 for Kerbal Space Program 1.7.0

Released on 2019-04-21

1.3 (April 21st, 2019):

  • [Change] KSP 1.7 compatibility.
  • [Fix #263] Missing files trying to compile locally.
  • [Fix #264] It's seems that KAS v1.2 do not support KSP v1.7.

Download (2.82 MiB)

Version 1.2 for Kerbal Space Program 1.6.1

Released on 2019-04-08

1.2 (Apr 8th, 2019):

  • [Change] ATTENTION! The lagacy parts are not provided in this verison!!! Read Wiki for more details.
  • [Enhancement] Add French localziation.
  • [Enhancement] Add Portuguese localziation.
  • [Enhancement #260] Add a setting to control the couple state on link.
  • [Change] Major update to the basic renderer module to increase UX experience.
  • [Fix #236] Support action groups in winches.
  • [Fix #252] NRE when entering the vessel from EVA.
  • [Fix #255] KAS link throws when loading save file.
  • [Fix #258] Connectors break on entering the physics bubble.
  • [Fix #260] Add a setting to control the couple state on link.

Download (2.82 MiB)

Version 1.1 for Kerbal Space Program 1.5.1

Released on 2018-10-30

1.1 (October 29th, 2018):

  • [Enhancement] Add ES-ES localization.
  • [Fix #249] Pylons are not get equipped when carried.

Download (5.60 MiB)

Version 1.0 for Kerbal Space Program 1.5.1

Released on 2018-10-23

1.0 (October 21st, 2018):

  • [Change] KSP 1.5 compatibility.
  • [Fix #238] Multiple RTS dialogs conflict with each other.
  • [Fix #239] RTS dialog cannot be moved.
  • [Fix #240] RTS-1 doesn't see all the resources on the vessel.
  • [Fix #241] RTS-1 doesn't allow passing fuel in the docked mode.
  • [Fix #242] Use resource definition to check if it can be transferred in RTS.
  • [Fix #244] GP-20 & BGP-400 are not in the KAS tab in VAB.
  • [Fix #246] Timewarp doesn't affect the RTS-1 transfer speed.

Download (5.59 MiB)

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