dartimos

You would need to make any prior missions invulnerable. Until they finish, any collision ends very badly for the current mission and inability to dock, etc. No interactions until that mission is / was finished (with some sort of proper notation of what you can interact with). Not elegant, but functional. I like some of the ideas floating around with reputation decay and such, especially as an option in career mode. However, I would be worried that it would be a limiting factor for large scale travel. How would a player"recover" from a mission that was long, hard and unsuccessful? Like AngelLestat said, there needs to be a balance of abusive mechanics of "free time" and the "time as a commodity" idea that limits freedom. The serial time along with time as commodity will punishing large scale failures (failed attempts that take lots of time naturally and not abusively). New players will suffer.

An option is to make the player able to go back forth in time post-mission. Once a mission is "finished" it is permanently locked into the system as an event that happened. The science is earned based on where the player is in the timeline. The player would, in effect, be controlling multiple ships easily in comparison to the one non-orbit mission that most players play. Any collision with a preexisting, non-finished part results catastrophically (down-side of this idea) and only affects the currently selected ship. This would make a Space-Race style possible as well as make a viable model for their future MP ideas. It also gives players the ability to race to a goal. ***However, I would shy from punishing the player for spending too much time doing what they want to do unless there is some purpose behind it other than arbitrarily increasing the difficulty.*** EXAMPLE I launch a mission (Operation Mun; OM) to the moon. Grab soil samples. Go home. Finish mission, locked in. I go back to an hour after I've launched OM. The science hasn't kicked in yet, so I can't unlock any new parts. As I blast into orbit on Operation Kerbal Orbit (OKO), I can see in where my last mission is in real time. I take observe some goo and radio it home. End the mission as I see OM landing. I go to my R&D, finally OM research has come home. In addition, OKO's research has been received. I pick up from this point and start with new shinies. I can go back in time if I want, but I won't have the shinies (I purchased them in the future).