The topic of discussion is some real-life applications of Kepler's Third Law in space aviation. Please search the Internet to look for actual examples of spacecrafts or natural satellites orbiting the Earth, the Moon, and other planets in the solar system (Mars, Jupiter, etc). The JPL website is a good place to start.

(1) For a given spacecraft or satellite, find its orbital altitude (and, hence, the radius of its orbit), the period of the orbit, and use Kepler's 3rd law to find the mass of the celestial body it revolves about. Does your result agree with the published value of the mass? Post a paragraph with your calculation and the link to the websites from which you obtained the data.