See Widnall's overview here which discusses some of the ground that crosses over with what has come to be known as backpropagation: The Minimum-Time Thrust-Vec

See Widnall's overview here which discusses some of the ground that crosses over with what has come to be known as backpropagation: The Minimum-Time Thrust-Vector Control Law in the Apollo Lunar-Module Autopilot (1970) https://www.sciencedirect.com/science/article/pii/S1474667017687731 https://www.sciencedirect.com/science/article/pii/S147466701...