David A. Brennan

David A. Brennan, 42, of Maynard, Massachusetts, passed away peacefully on August 17, 2025, surrounded by the love of his family, after a courageous and hard-fought battle with cancer.

Born in Butler, Pennsylvania and raised in Dover-Foxcroft, Maine, David carried the warmth of small-town roots into every relationship and endeavor. He built an extraordinary and fulfilling career at Raytheon, where he worked for over 20 years, and left a lasting impact in the field of strategic and protected satellite communications. David was a beloved son and brother, but above all, a devoted husband and a loving father to his two daughters, whom he considered his greatest joy and proudest legacy.

David loved many things in life: the crisp sound of a well-struck golf ball, the salty air and crashing waves in York and Rye, a plate of fresh seafood shared with the people he loved, and a perfectly cooked piece of meat - especially if it came from his own smoker. He found deep peace on the waters of Sebec Lake and by a crackling fire under the stars. He felt fortunate to have remained close with many of his childhood friends. Their enduring presence brought laughter, comfort and meaningful connection throughout his life.

In his youth, David was an avid soccer and tennis player and spent countless winter days snowboarding with friends on the slopes. Later in life, he developed a love for ice hockey and embraced the challenge of learning something new with characteristic determination. He was fiercely competitive - whether playing a game, solving a complex problem at work, or facing his greatest adversary, cancer - he approached each with steady, relentless resolve.

David was a remarkable engineer and earned the distinguished rank of technical fellow at an early stage in his career. He was nationally recognized for his domain knowledge in survivable satellite communications terminals and his innovative algorithms for controlling aircraft and shipboard antennas under the worst-day conditions are implemented and working inside some of our nation’s most vital assets. David was a natural leader who led large, multi-disciplinary teams through complex engineering challenges with skill and integrity. Known for his straight-forward and pragmatic problem-solving and ability to explain complex topics to any audience, he earned the deep respect of colleagues, senior government leaders and the broader satellite communications community. Never one to boast - he let his work, and his quiet dedication, speak for itself.

Of all the roles David held in life, none brought him more meaning or joy than that of being a dad. He was a cherished husband to Chelsey Brennan (née Killam), and a proud, loving father to his two beautiful daughters, Caroline Emery Brennan (13) and Emily Adams Brennan (9), whose lives he shaped with quiet strength, curiosity, and endless affection. Though still young, David and Chelsey were fortunate to share 25 years of memories together, including 16 years of marriage. He poured his heart into creating a family life full of love and laughter, leaving behind a presence that will guide and inspire them always.

David is survived by his father, John “Jay” Brennan and wife Dorothy “Dottie”; his mother, Cindy Caldwell and husband Terry; his siblings John Brennan (Kerry), Jayme Chenoweth (Dave), Katie Essig (Daniel), Tim Caldwell (Meagan), Stephen Caldwell (Caitlin), Ellen Jacott (John), and Anne DeLuck (Todd), and their families.

David’s legacy is one of quiet integrity, deep loyalty, and enduring love. Though his absence leaves a space that cannot be filled, his spirit lives on in the lives he touched, and in every warm fire, crashing wave and perfectly smoked brisket.

A public visitation will be open to all who wish to pay their respects on Friday, September 5, 2025, from 5:00 p.m. - 8:00 p.m. at the Fowler-Kennedy Funeral Home, 42 Concord Street, Maynard. David’s Memorial Service will be celebrated on Saturday, September 6, 2025, at 11:00 a.m. at Mt. Calvary Lutheran Church 472 Massachusetts Ave, Acton, MA 01720. In lieu of flowers, the family asks that donations be made in David’s honor to a GoFundMe established to help provide his daughters with the experiences he dreamed of giving them throughout their lives. https://gofund.me/d24c510c 

Share your favorite photos and memories about David at www.mykeeper.com/DavidBrennan13 These treasured moments will be gathered and shared with his children so they can grow up surrounded by the love and memories that shaped who he was.