Hi, Current model of unlocking several parts given the number of research points provided by transmitting the scientific experiences seem a bit flawed. Because a player by simply taking a lab into kerbin's orbit would be enough to unlock entire tree in few days or hours. My suggestion goes for the unlock not of the group of items (node) on the tec tree as it is currently presented. - Each item could well remain assign to existing tech tree but the unlock is not made at node level but item (part) level... this would allow connections for example Rockomax Mark 55 radial can only be "researched" once Rockomax 24-77 is researched (unlocked) - Each part (item) could have a specific research time (based on hours/days/months) and a "variable of success (or chance of success - I'll explain this further) - The research lab could have 2 up to 5 research slots so this would mean only 2-5 parts could be researched at same time (you could well use the research points or economy to add more research slots) - Once a research slot available we could assign one or more kerbals into research (1-5), therefore forming (scientists/engineers rather than just "astronauts") the more kerbals assigned to researched project, that would reduce a fraction of time taken to research that part and increase the "variable of success" - Once the research of a part (item) is under way, the player can only cancel it but not changing it (so not adding more kerbals into the research project) - Variable of success is a percentage/chance of success. So after the research period it could be a success or a failure (if is a failure then the player could well set new research for the part) Example: To research the part "LV-T45 Liquid Fuel Engine" it would take about 175 days for one Kerbal to find it how it works... Now if we add up to 5 kerbals to that project, it would reduce a percentage of that time (from 175 days lets say down to 130 days) With a single kerbal researching, success rate is just 40% for that item. But with 5 on the team, the percentage of success raised up to 60%... this means there is 60% chance the player will get the part researched after those 130 days. Benefits What this would give to the player is the sense there is some research happening where the player will be able to fine tune the items he wants to unlock (by researching them) rather than unlocking groups of items in just one go after few hours play. It also allows the introduction of new kerbal classes (researchers/scientists/engineers) which could allow you to implement in the future a kerbal know-how (so to lower the dumb side of them) which would mean... a kerbal involved with one successful research would know a bit less dumb (so reducing research time and increasing success variable) compared with a brand new dumb kerbal that has done no research before. Be well