A study was made on a six-degree-of-freedom fixed-base simulator of the ability of a human pilot to modify hyperbolic ballistic trajectories of a space vehicle approaching the moon so as to establish a circular orbit 50 miles above the lunar surface. The pilot was given control of thrust along the vehicle's longitudinal axis and torques about all three body axes. The results showed that by using a hodograph presentation of rate of descent and circumferential velocity, an altimeter, and vehicle attitude and rate meters, the pilots could consistently establish final altitude and velocity combinations that result in orbits lying within an altitude range of 10 to 90 miles above the lunar surface with a fuel consumption from 1 to 3 percent of the initial vehicle mass more than that required by the two-impulse Hohmann maneuver. (Author).