  Quadrupedal landing is a complex process involving large impacts, elaborate
contact transitions, and is a crucial recovery behavior observed in many
biological animals. This work presents a real-time, optimal landing controller
that is free of pre-specified contact schedules. The controller determines
optimal touchdown postures and reaction force profiles and is able to recover
from a variety of falling configurations. The quadrupedal platform used, the
MIT Mini Cheetah, recovered safely from drops of up to 8 m in simulation, as
well as from a range of orientations and planar velocities. The controller is
also tested on hardware, successfully recovering from drops of up to 2 m.
