Len Kasten has a B.A. degree from Cornell University, where he majored in psychology and minored in literature and philosophy. After graduating from Cornell he entered the U.S. Air Force Aviation Cadet program. While in the Air Force he experienced a UFO encounter that had a transformative effect on his life, although he didn't realize it until a few years later. After serving in the Air Force he moved to Richmond, Virginia. On frequent trips to Virginia Beach, he spent a lot of time in the extensive New Age library at the Association for Research and Enlightenment (A.R.E.), the organization founded by psychic Edgar Cayce, where he acquired a self-education in metaphysics. He then moved to Boston where he was introduced to Theosophy and joined the Boston Theosophical Society.
Then later, while working in Washington D.C. in the 1960s, he felt drawn to join the National Investigations Committee on Aerial Phenomena (NICAP). NICAP was the most prestigious organization in the country investigating UFO phenomena. At that time, in the mid-1960s, there was a wave of UFO sightings all across the country, and NICAP was precisely in the eye of the storm. It was swamped with inquiries from the public and the media, and was the major source of information nationally for UFO reports. Thanks to its thorough, careful field investigation program, NICAP was able to provide solid evidence to the press, which had the effect of embarrassing the government into beginning its own serious UFO investigation - the now infamous Project Blue Book.