Which facility upgrade unlocks maneuver nodes in career mode in KSP?
The beta announcement hints that maneuver nodes are now unlocked with a facility upgrade:
Are there any perks for upgrading?
The building in question
will upgrade visually, both from the outside and the inside. More
gameplay mechanics will be also be unlocked as the player progresses
through the different building tiers. For example, allowing EVAs in
space or being able to use maneuver nodes in the map view.
Best Answer
You have to upgrade 2 buildings: the tracking station (to level 2) and the mission control (to level 2).
Just one by itself is not enough. If you upgrade mission control without the tracking station, you'll see a message telling you that "flight planning" is not available until the tracking station is upgraded.