Which facility upgrade unlocks maneuver nodes in KSP

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.

Solution 1:

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.

Solution 2:

As of 0.90 maneuver nodes are unlocked by buying the first upgrade to the Tracking Station.

Solution 3:

Mission Control (the place where you get contracts) the upgrade is called "flight planning". The tracking station lets you unlock conics which I think are simply the predictions of intercepting celestial bodies, etc. I unlocked the tracking station first, which gave me the blue/purple lines etc. but no ability to place maneuver nodes.