Dr. Zachary Smith (Jonathan Harris), Alpha Control’s doctor, is revealed to be a saboteur working on behalf of an unnamed nation. After disposing of a guard who catches him aboard the spacecraft, Smith reprograms the Jupiter 2’s B-9 environmental control robot (voiced by Dick Tufeld) to destroy critical systems on the spaceship eight hours after launch. Smith becomes trapped aboard at launch, however, and his extra weight throws the Jupiter 2 off course, causing it to encounter asteroids. This, plus the robot’s rampage, causes the ship to prematurely engage its hyperdrive, and the expedition becomes hopelessly lost in the infinite depths of outer space. Smith’s selfish actions and laziness frequently endanger the expedition, but his role assumes less sinister overtones in later parts of the series.