Answer:
Mathematics, science, or technology.
Explanation:
For a person to work as an astronaut or an aspiring astronaut, there are certain fields of academic preferences that will help in ensuring one gets employed. These backgrounds will help in the future endeavors of the person to be a part of the space exploration team.
For an aspiring astronaut, having degrees in the fields of mathematics, astronomy, atmospheric sciences and physics are the main necessities. moreover, having knowledge and academic background in technology will also help save a spot for him/ her.
Thus, the correct answers are mathematics, science, or technology.