The finished release of Kerbal Space Program will include official multiplayer modes, according to developer Squad. How exactly a multiplayer mode will work mechanically is undecided, but Squad says it's committed to building beyond the current singleplayer model.

“Multiplayer is something we had planned to do after it was all said and done, but it's time for us to start looking at it now,” developer Felipe Falanghe said at a team meeting in Mexico City today. Squad envisions four discrete game modes: the classic sandbox, the newly launched career mode, and multiplayer versions of both sandbox and career mode.

As Squad continues to work toward a scope-complete build of Kerbal Space Program, it will also begin placing the basic requirements for a multiplayer server architecture. A multiplayer mod built by the KSP community recently entered an early alpha build, and Squad credits modders with providing a solid proof-of-concept.

“Shaun [Esau, the developer of the multiplayer mod] has proven that multiplayer can be done, so Squad is committed to making multiplayer a part of the final release,” Squad PR manager Bob Holtzman said.

The big technical hurdle preventing multiplayer from being added to KSP is the problem of multiple timelines. Because space travel in the game sometimes takes days or months, a fast-forward function has been an essential mechanic since very early in the development process. With multiple players, a player fast-forwarding to travel to the moon would enter an alternate timeline several days ahead of other players.

To solve this issue, the multiplayer mod allows players in the past to catch up with players in the future. Syncing timelines will also be a solution that Squad will look for in their multiplayer modes. Developers will have access to more powerful tools than modders, however, so the solution will not be based on code from the mod. “It would be entirely our own implementation,” Falanghe confirmed.

The plan, for now, is that Squad will begin developing the multiplayer mode sometime next year. The modes will be officially announced during the closing hours of the Kerbal Kon livestream on Friday.