Theodore Eugene Fessler passed away peacefully at his home in Mount Dora, Florida, on February 17, 2026 at the age of 95. Born on March 22, 1930 in Cleveland, Ohio to Eleanor Louise (Joecken) and Carl Henry Herman Fessler, he attended Adelbert College of the Western Reserve University where he graduated with a BS degree in Chemistry.

He then attended the Graduate School at Western Reserve, earning an MS degree in Physics. His career at the NASA Lewis Center spanned research in nuclear physics and later computer programming. In 1954 he married Eleanor Richardson, then a student at the Frances Payne Bolton School of Nursing of WRU, and they had four daughters, whom they raised with love and kindness.

When their children were young, Ted and Eleanor took them on camping adventures across the country.Later they fell in love with sailing and spent every summer cruising the Great Lakes. After Ted retired from NASA, the two left the cold winters of Ohio to spend more than a decade living aboard their sailboat Canopus in the Caribbean Sea. They learned to scuba dive, and did so on an almost daily basis.

Ted's last decades were spent in Mount Dora Florida, where he and Eleanor welcomed visits from their children and grandchildren in between their own adventures traveling both domestically and internationally.

Ted will always be remembered as an excellent husband, father, and grandfather. His scientific mind drove his down-to-earth personality. He was unassuming despite having plenty of which to be proud.

Ted was predeceased by his wife Eleanor and daughter Patricia Ann. He is survived by his daughters Erika, Sarah, and Susanna, and grandchildren Jennifer, Max, and Kate.