added discussion of satellite conventions
added discussion of satellite conventions

mhvk/astropy,dhomeier/astropy,larrybradley/astropy,lpsinger/astropy,larrybradley/astropy,mhvk/astropy,pllim/astropy,astropy/astropy,StuartLittlefair/astropy,aleksandr-bakanov/astropy,mhvk/astropy,astropy/astropy,larrybradley/astropy,aleksandr-bakanov/astropy,lpsinger/astropy,pllim/astropy,dhomeier/astropy,dhomeier/astropy,lpsinger/astropy,StuartLittlefair/astropy,dhomeier/astropy,astropy/astropy,mhvk/astropy,pllim/astropy,aleksandr-bakanov/astropy,StuartLittlefair/astropy,saimn/astropy,saimn/astropy,StuartLittlefair/astropy,astropy/astropy,saimn/astropy,lpsinger/astropy,saimn/astropy,dhomeier/astropy,astropy/astropy,StuartLittlefair/astropy,larrybradley/astropy,pllim/astropy,lpsinger/astropy,pllim/astropy,mhvk/astropy,saimn/astropy,larrybradley/astropy,aleksandr-bakanov/astropy