Diane Marie (McManus) Mangel, lovingly known as "Mimi," 76, of Mechanicsville, Maryland, passed away peacefully on Saturday, February 28, 2026, at her home, surrounded by loved ones, after a courageous battle with cancer. Born on July 30, 1949, in Buffalo, New York, Diane was the cherished daughter of the late Captain Thomas McManus and Margaret (Mandly) McManus. She was preceded in death by her parents and her beloved brother, Gregory McManus.

The oldest of four children, Diane treasured her role as a big sister. She shared a lifetime of love and memories with her siblings, Maureen Wroblewski and Thomas McManus, Gregory McManus, and was deeply proud of her family roots.

A proud graduate of La Reine High School, Diane went on to build a remarkable 36-year career in federal service. As a dedicated member of the Public Affairs team at NASA Headquarters, she supported the Kennedy Space Center launches and the nation's space program with excellence and pride. She coordinated space shuttle launches, astronaut appearances, and countless significant events. Diane loved sharing stories of attending and organizing launches, meeting astronauts, and even crossing paths with well-known figures such as Leonardo DiCaprio.

Her career brought her extraordinary lifelong friendships. She was a proud member of the "Wise Women of NASA," and in recent years took over coordinating their cherished luncheons — a role she embraced with joy, gratitude, and her signature attention to detail. Diane's federal service was decorated with numerous awards recognizing her critical performance and key support throughout her tenure.

Diane's love for her community extended far beyond her professional life. She served as Director of Marketing for two years with the St. Mary's County Historical Society, where she was also actively involved among the directors and committee chairs. She was passionate about preserving local history and celebrating the stories that shaped her beloved county.

Diane is also a lifetime member of the Mechanicsville Volunteer Rescue Squad, serving as secretary for 12 years. She loved the Rescue Squad and every single member; they were family to her. Her volunteerism earned her many awards and accolades, including being named a Hometown Hero in 2023 — an honor that perfectly reflected her heart for service.

But above all else, Diane's pride and joy was her family. She was the devoted mother of Julie Kidwell (Robby), Albert Mangel (Brenda), and Tara Payne (Todd), and a loving foster mother to Devon Thomas. She was the proud grandmother of Christine Quade, Katelyn (Kidwell) Samblanet, Savannah Kidwell, Robby Kidwell, Andrew Mangel, Rachel Mangel, Catherine Payne, and Christopher Payne, and the adoring great-grandmother of Dylan Lumpkins, Brian Quade, Kevin Allshouse, Memphis Allshouse, Josie Allshouse, Ace Samblanet, Archer Samblanet, Gracelyn Kidwell and Lainey Kidwell.

Diane loved everything that sparkled and everything natural — fitting for a woman who sparkled so brightly herself. She found joy in dancing, laughing, fishing, gardening, traveling, and preparing traditional Hungarian meals that kept family traditions alive. Her home in Mechanicsville was one of her greatest accomplishments. If you walked the Three Notch Trail, you likely saw her tending her yard or working tirelessly on her latest home project. She beamed at compliments, not out of vanity, but out of pride in the life she built.

Diane was a confidant, a protector, a cheerleader, and a constant. She loved without bounds, gave without question, and lived with a compassion that was both fierce and tender. Her heart was her greatest gift, and she shared it freely with the world.

Her life was beautiful. Her love was immeasurable. And she was, and always will be, like no one else.

Funeral and Services:
A viewing will be held on Tuesday, March 10, 2026, from 5:00 p.m. to 7:00 p.m. at Brinsfield Funeral Home - in Charlotte Hall, MD. Prayers will be offered at 7:00 p.m.

The Funeral Mass will take place on Wednesday, March 11, 2026 at 10:00 a.m., at Immaculate Conception Church - in Mechanicsville, MD.

Burial will follow at Queen of Peace Cemetery - Mechanicsville, with a Celebration of Life gathering to follow the interment.

Pallbearers: Albert Mangel, Andrew Mangel, Brian Quade, Robby Kidwell, Devon Thomas and David Thorne

In lieu of flowers, please make a donation to the Mechanicsville Rescue Squad

Condolences may be made to the family at www.brinsfieldfuneral.com

Arrangements by Brinsfield Funeral Home & Crematory, P.A., Charlotte Hall, MD.