You don't have to include the boring bits of who paid for the research or the day to day lives of the researchers. That isn't science, and it doesn't help the student understand science. A mere description of the fact that Tycho Brahe kept meticulous records of the positions of the planets in the sky and a walkthrough of the math that shows this data matches elliptical orbits and the math that shows that Newton's laws lead to those elliptical orbits is sufficient. The fact that there is a discrepancy for Mercury motivates further developments.