Len Eastman was born in 1933 in Bernardston, Massachusetts. After graduating from Northeastern University in Boston, Massachusetts, he entered the Naval Aviation Officer Candidate School on October 23, 1957. Ens Eastman next completed flight school and Photographic Reconnaissance Officer School before serving as an RF-8A Crusader pilot with VFP-63, followed by service as a flight instructor at NAS Kingsville, Texas. After attending the U.S. Naval Postgraduate School, LT Eastman returned to VFP-63 at an RF-8A pilot, and served two combat tours in Southeast Asia from October to November 1965 while flying from the aircraft carrier USS Oriskany (CVA-34), and then aboard the aircraft carrier USS Hancock (CFA-19) from May 1966 until he was forced to eject over North Vietnam and was taken as a Prisoner of War on June 21, 1966. After spending 2,429 days in captivity, CDR Eastman was released during Operation Homecoming on February 12, 1973. He was briefly hospitalized to recover from his injuries, and then attended Navy Comptroller School. His final assignment was at Naval Station Annapolis, Maryland, where he retired from the Navy on November 1, 1983.

His Silver Star Citation reads:

For conspicuous gallantry and intrepidity while interned as a Prisoner of War in North Vietnam. In June 1966, his captors, completely ignoring international agreements, subjected him to extreme mental and physical cruelties in an attempt to obtain military information and false confessions for propaganda purposes. Through his resistance to those brutalities, he contributed significantly toward the eventual abandonment of harsh treatment by the North Vietnamese, which was attracting international attention. By his determination, courage, resourcefulness, and devotion to duty, he reflected great credit upon himself and upheld the highest traditions of the Naval Service and the United States Armed Forces.