In reality, the number of astronauts is pretty limited as is the number of princesses so it is just probabilistically unlikely that there is some combination.
In fact, I bet the percentage of princess astronauts vs. non-princess astronauts is pretty close.
Wouldn't surprise me if a princesses are more likely to become astronauts than an average person. If they really want to go to space they have things to offer in return.
In reality, the number of astronauts is pretty limited as is the number of princesses so it is just probabilistically unlikely that there is some combination.
In fact, I bet the percentage of princess astronauts vs. non-princess astronauts is pretty close.