Theresa Helen Spaeth, 46, passed away Wednesday, March 4, 2026, at Houston Methodist Clear Lake Hospital in Houston, Texas. She was born on September 1, 1979, in Houston, Texas to Leo Spaeth Jr. and Peggy Spaeth. She is preceded in death by her parents, Leo (Jr.) and Peggy, as well as her grandparents, Howard and Rose Proske, and Leo (Sr.) and Edith Spaeth. She is survived by her sister, Rebecca Spaeth Peters and her husband, Seth Peters; her niece and nephew, Juliana and Jacob; along with extended family of aunts, uncles, and cousins.

Theresa was an exceptional scholar, achieving at the highest levels throughout high school and college. She graduated co-valedictorian from Spring Woods High School in Houston in 1997. She then went on to attend Texas A&M University as a member of the Class of 2001 and graduated in May 2002 with a Bachelor of Science in Aerospace Engineering. At Texas A&M, she was one of only nine students in the College of Engineering to graduate with a perfect 4.0 GPA, maintaining the standard of excellence she had become known for throughout her academic career. Following her graduation, Theresa began her career with United Space Alliance, where she spent two years training astronauts in NASA’s Shuttle Program. In 2004, she chose to return to academia to pursue advanced studies in aerospace software. After being awarded a National Defense Science and Engineering Graduate Fellowship, she returned to Texas A&M University to work with Dr. John Valasek, focusing on simulation software and evaluating human factors and pilot workload. In December 2006 Theresa earned her Master of Science in Aerospace Engineering.

Theresa’s two degrees in Aerospace Engineering and her love of spaceflight led her to become NASA’s Orion Software Manager as part of the Artemis Program, a role she held until her unexpected and untimely passing. For almost 20 years, she dedicated her life to NASA and the quest to send astronauts to the Moon and beyond. Through her work on the Orion spacecraft, she built an extended family of NASA and Lockheed Martin colleagues. To Theresa, the people she worked with were not just coworkers; they were friends and family. She was known for always being available whether it was logging on late at night, answering messages at any hour, or stepping in whenever her extended work family needed her. She brought intelligence, dedication, and a special work ethic to everything she did, all grounded in a calmness that those around her deeply appreciated. Her efforts did not go unnoticed. In 2012, Theresa earned NASA’s Early Career Achievement Medal, a prestigious award recognizing government employees for unusual and significant performance during the first ten years of their career and recognizes individuals’ outstanding contributions to NASA’s mission.

Theresa loved to host, and she was truly great at it. Her gift for bringing people together started in high school, when she would spontaneously invite friends over to pack the living room and cheer on the Houston Rockets during the NBA Finals. That spirit only grew in college and beyond, where she became the goto host for postfootballgame gatherings, Friendsgiving celebrations, her much- awaited themed Halloween parties, trips to the family river house, and countless other gettogethers. And at every one of these events, no one ever left hungry or thirsty because food and drinks were always abundant. Everything she did reflected the warmth, generosity, and genuine goodness of who she was in life.

Much like her parents, Theresa also loved to travel. She enjoyed trips with friends to Europe and family vacations with her parents, sister, brother-in-law, niece, and nephew. In 2012, Theresa’s mother was diagnosed with an autoimmune disease, known as Primary Lateral Sclerosis (PLS). As the disease progressed and limited her mother’s mobility, Theresa began planning elaborate weeks- long road trips each year for her and her parents to visit National Parks and iconic destinations. These trips allowed her mother to continue experiencing the beauty of the world and gave Theresa cherished time with her family. After her mother passed away in February 2021 from Amyotrophic

Lateral Sclerosis (ALS), Theresa continued to plan and take trips with her dad, sister, and her sister’s family. Some of those trips included Thanksgivings in Mountain Home, Texas, Disney cruises to the Bahamas and Alaska, and a visit to the McDonald Observatory in Fort Davis, Texas.

Theresa was so much more than an academic scholar, career achiever, amazing host, and travel enthusiast. She was a kind soul, a supportive sister, an incredible gift-giver, a thoughtful friend, the best aunt, and someone everyone simply loved to know and be around.

The absence of her presence is felt deeply by her family and friends. Her sister misses texting her pictures of the kids and sharing their accomplishments. Her niece and nephew miss their craft buddy. Theresa’s two cats, Nox and Luna, miss their momma and her warmth. She may have briefly lost touch with some over the years, but her impact on the lives of those who knew her will last forever.

In the end, Theresa continued to give in the way she always had. She chose to be an organ donor, offering someone else the gift of life. It was a final, profound expression of the generosity and compassion that defined her.

A funeral Mass will be held on Saturday, March 21, 2026, at 10:30 AM at St. Catherine of Siena Catholic Church, located at 10688 Shadow Wood Dr., Houston, Texas 77043.

In lieu of flowers, the family requests that gifts be made to St. Catherine of Siena Catholic Church in Houston, Texas, or that donations be made in her name to Texas A&M University.