I had the same question during my first (solo) playthrough. I ALMOST ended up leaving myself with no legal placements, and noticed it just in time to move an astronaut and avoid disaster! But I was still left wondering what happens in that case... and luckily, there's an answer in the FAQ:
What happens when I have no options to build any the blueprint tiles showing in the queue?
While this comes up VERY RARELY (theoretically never with decent planning), mistakes happen and this comes up once in a while. Our solution is to pay 5 points and move one of your astronauts to any tile in your base plan (just like the DRINK action of the expansion). That should do enough to find you a place to build. Note: this rule is not there to be abused, but as an escape valve for newer players.