When to Use Apollo Free-Return Trajectory 3D Explorer - Best Sessions and Limits
Open the Apollo Free-Return Trajectory 3D Explorer when you need a lunar free-return vs hybrid path comparison - without a patched-conic mission designer.
A crew-safety trajectory lesson
A crew-safety lesson starts when you open the explorer on Free-return (early design PC ~110 km), scrub to the lunar flyby, then switch to Hybrid to show why Apollo 13 needed the 34.23 s DPS-1 burn at GET 61:29:43 after the oxygen-tank failure.
Apollo 13 distance and pericynthion figures
Apollo 13 distance and pericynthion figures land cleanly here: 400,171 km furthest from Earth at PC, ~250 km restored free-return lunar altitude, and the ~2,500 nmi hybrid Earth perigee that would not capture.
Sessions this explorer does not fit
Sessions this page does not fit are two-burn circular-orbit transfers or full mission design. Use the Hohmann Transfer 3D Explorer for delta-v ellipses between circular orbits. Walk the controls in the step-by-step guide.
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