Susan G. Finley has been an employee of NASA’s Jet Propulsion Laboratory (JPL) since January of 1958, making her the longest-serving woman in NASA. Two days before Explorer 1 was launched, Finley began her career with the laboratory as a human computer, calculating rocket launch trajectories by hand. She now serves as a subsystem engineer for NASA's Deep Space Network (DSN). At JPL, she has participated in the exploration of the Moon, the Sun, all the planets, and other bodies in the Solar System.