Charles W. Haldeman III (Chuck), age 82, of Concord, died peacefully at his home at the Lincoln Commons on Friday, July 6, 2018. He was the devoted husband for 59 years of Louise (Stephenson) Haldeman, father of two sons, and grandfather to three granddaughters. Born in Philadelphia in 1936, he was the son and only child of Charles Waldo Haldeman, Jr. (Waldo) and Anna Douglass Haldeman. He spent part of his boyhood in Washington, DC where his father worked in a wartime government position, and where he and his family lived with his bachelor uncle, Paul Douglass, so that his mother could act as hostess while he served as president of American University. During that time, Chuck had a chance to meet many interesting people, and little "Chucky" was known to be a terror with the champagne bottles, corks, and dry ice that accumulated after parties at the University Presidents mansion. One person of interest was a visiting professor who was enlisted to give Chuck piano lessons, but ended up teaching him the chemistry of fireworks and explosives, instead. Despite his relative lack of aptitude for piano and continued interest in chemistry, pyrotechnics and all science, Chuck was an ardent lover of music and a BSO subscriber throughout his life. Following the end of the war, Chuck and his family returned to the Philadelphia area where he attended and graduated Lower Marion High School. During that time, he was an outstanding student and athlete, winning an athletic scholarship to Penn State for gymnastics, but opting to attend MIT to study engineering, instead. He enrolled at MIT in 1954, and received his B.S. and M.S. as part of the honors program in the Department of Aeronautics and Astronautics (Course 16). He then continued as a graduate student at the MIT Aero-Physics Laboratory where he worked at the hypersonic test facility and completed his Doctorate (ScD) in 1964. Chuck continued to work in hypersonic testing for the next 14 years, while also consulting at a small technology company, Megatech, initially based largely on his inventions. Eventually the demand for high-speed wind tunnel testing dried up, and in 1978 Chuck moved to MIT Lincoln Laboratory where he worked for 20 years in the Aerospace Engineering Group, ultimately as Senior Staff. Always interested in commercializing new technology, but unable to continue in his consulting roll at Megatech while working at Lincoln, Chuck took advantage of an early retirement opportunity in 1998 and went to work at a small startup, Supercritical Combustion, which developed novel energy technology based largely on his patented ideas. He finally returned to Lincoln in 2004 and worked until his final retirement in 2012. Chuck was a proud inventor over his career, patenting and developing a number of new technologies including a travelling wave vacuum pump, glass cylinder based transparent engine, electromagnetic dynamometer, one of the first ground-water based heat pump systems, a method for balancing RF inductive heating loads, and a supercritical diesel – water based combustion technology. Chuck also contributed many novel ideas and a lot of hard work to the less open, national security related projects he worked on over his career. In addition to hypersonics, he worked professionally in material technology development, energy system and battery development, and the study of anomalous energy phenomena. Most of all, Chuck enjoyed working with his colleagues at all levels in his professional career and took particular pleasure in getting to know and helping to train and mentor many young engineers, scientists, and technicians. In his family and home life, Chuck was a devoted husband, father, grandfather, teacher, mentor, and friend. He courted his wife during his final undergraduate and early graduate years at MIT and they were married in 1959. They lived briefly in Boston, moved to Lexington where they started their family and lived for 12 years, and finally moved to Concord in 1972 where they completed raising their family and continued to live together until Chuck's illness became too much to manage. Chuck was a lifelong tinkerer, woodsman, hunter, gardener, and farmer spending many childhood summer months and family weekends at his family farm in Granville, NY. As a father living in Concord, Chuck was the Scout Master of Troop 132 for a number of years partaking and then leading a great deal of hiking, camping, and canoeing activities. As a fairly experienced hunter and woodsman, hiking trips were relatively easy but he learned canoeing on the job by applying basic aeronautical principles. Chuck would also run an open neighborhood clinic for car, bicycle, and general repairs on weekends and evenings, and his garage was frequented by many neighborhood boys and a few fathers. He and Louise were longtime members of Hancock Church in Lexington where Chuck served on several committees. In Concord, he served on the Board of Health for two terms and was a member of the original town committee, appointed to consider the former Nuclear Metals site. In his later years, Chuck was devoted to his granddaughters, reading to them and bringing them out to learn about nature during some of his final trips to the family farm. He was also a devoted wild mushroom hunter throughout his life and battled to keep squirrels off of bird feeders for decades. Chuck owned, operated, and maintained the same snow blower for his entire, fifty three years as a home owner. In late 2011, Chuck was diagnosed with Parkinson's disease and retired from Lincoln Laboratory the following year. Due to the disease progression, he was hospitalized and finally moved to the Harbor Assisted Living community at the Lincoln Commons in 2016. While his short term memory had failed badly, his long term memories and personality were intact until just a few weeks before he passed away and his family and friends were able to see him and say goodbye. In addition to his wife, Louise, Chuck leaves behind his sons Charles W. Haldeman IV (Charlie) and George S. Haldeman, his daughters in law, Margaret T. Haldeman and Sioban M. Haldeman, and his granddaughters, Katharine E. Haldeman, Claire A. Haldeman, and Maeve C. Haldeman. Relatives and friends will gather for his memorial service on Saturday, August 18th at 2 pm in the Hancock United Church of Christ, 1912 Massachusetts Avenue, Lexington. A reception will immediately follow. Private interment will be at Sleepy Hollow Cemetery in Concord. In lieu of flowers, contributions in his memory may be made to the Concord-Carlisle Community Chest, 19 Main Street, Suite 2, Concord, MA 01742. Arrangements are under the care of Dee Funeral Home & Cremation Service of Concord.