The paper for it is readable - Fast Reconnaissance Missions to the Outer Solar System Derived from the Gravitational Field of Jupiter http://www.gravityassist.c

The paper for it is readable - Fast Reconnaissance Missions to the Outer Solar System Derived from the Gravitational Field of Jupiter http://www.gravityassist.com/IAF3-2/Ref.%203-143.pdf http://www.gravityassist.com/IAF3-2/Ref.%203-143.pdf (1966) Also fun to play with is: https://trajbrowser.arc.nasa.gov/index.php https://trajbrowser.arc.nasa.gov/index.php (example query with multiple flybys of outer planets - https://trajbrowser.arc.nasa.gov/traj_browser.php?NEAs=on&NECs=on&chk_maxMag=on&maxMag=25&chk_maxOCC=on&maxOCC=4&chk_target_list=on&target_list=Jupiter%0D%0ASaturn&mission_class=oneway&mission_type=flyby&LD1=2015&LD2=2030&maxDT=5&DTunit=yrs&maxDV=20&min=DV&wdw_width=365&submit=Search#a_load_results https://trajbrowser.arc.nasa.gov/traj_browser.php?NEAs=on&NE... )