In my current playthrough, I got anti gravity race track mission, as well as anti gravity time trial mission, but still have not gotten the introductory mission to anti gravity vehicles that allows you to purchase the "Bobblecraft". That mission should be available BEFORE the other ones. I'm quite far into the game and have explored a huge area of the map, and still cannot trigger that mission at any trading station.

Here's a screenshot of how far I've explored so far, trying to get this mission:
https://steamhost.cn/steamcommunity_com/sharedfiles/filedetails/?id=3255792862