Helmut Justus Karl Horn (June 24, 1912 - January 20, 1994)[2] was a German-American engineer and applied physicist who was employed at the early Marshall Space Flight Center.
Horn worked first at the Peenemünde Army Research Center and later, after the end of World War II, was hired by the U.S. through Operation Paperclip.
[2] As a member of von Braun's rocket team, Horn was one of the engineers scouted by Operation Paperclip.
After arriving Horn worked within the U.S. rocket program, first at Fort Bliss and then at White Sands.
He adapted the bilinear tangent steering law developed by mathematician Derek Frank Lawden, creating an algorithm that would improve upon existing software to calculate optimal in-flight trajectories.