Eastlund attended MIT, receiving a B.S Physics degree in 1960. In 1965, he received a Ph.D. in plasma physics from Columbia University, and spent 3 years as a post-doc fellow there. Eastlund became a staff member at the fusion office at the U.S. Atomic Energy Commission (USAEC) in 1968. The USAEC recognized Eastlund's paper, "The Fusion Torch" co-authored with William C. Gough, with a Special Award in 1970. Scientific American magazine published a review of fusion programs by Eastland and Gough in 1971.