Orbit Perigee
"On an elliptical orbit path, the point where a satellite is closest to the Earth" (National Aeronautics and Space Administration, 2014)
Sources
"Perigee". NASA Glenn Research Center, National Aeronautics and Space Administration. Last modified June 12, 2014.
https://www.grc.nasa.gov/www/k-12/TRC/laefs/laefs_p.html#period.
Accessed February 1, 2019.