Gaelen Roger Daum was born in Pensacola, Florida, on May 29, 1947, to Gordon Andrew Daum and Helen Louise Daum, n é e Destocki.  Gordon was a naval aviator and later a Safety Inspector with the Federal Aviation Administration.  The family moved often spending time in Florida, California, New Jersey, and Oklahoma, before settling in Ohio.  Gaelen excelled in math and science in school as well as participating in activities such as chess and wrestling at U. S. Grant High School in Oklahoma City where he graduated in 1965.  He attended Oklahoma City University where he earned Bachelor Degrees in Math and Physics.  At OCU he met Mea Ball, who was studying journalism.  Gaelen and Mea were married December 29, 1969.  The newlyweds moved to Charlottesville, Virginia, where Gaelen attended graduate school at the University of Virginia.  While in graduate school, he joined the U.S. Army Reserve Officers' Training Corps (ROTC) which allowed him to complete his Master's Degree in Theoretical Physics and complete his Army active duty service at the U.S. Army Ballistic Research Laboratory at Aberdeen Proving Ground, Maryland.  While living in Maryland their daughter, Arwen Emily, and son, Nathan Christopher, were born.  In 1982, Gaelen was offered a job in California's burgeoning aerospace industry and the family moved to Poway in San Diego County, where they have remained.  Gaelen worked for various companies in the aerospace and defense industries, including Global Analytics, Alcoa Defense Systems, and McDonnell Douglas Corporation.  He stayed busy with a variety of "retirement jobs" before finding his second calling working in the tool corral at the Home Depot in Mira Mesa, CA.  This gave him ample opportunity to learn about tools, talk about tools, and often buy more tools to the delight of some of his family and the chagrin of others.  Always interested in anything mechanical, Gaelen became a certified locksmith and would practice or try out new locks on the family home; sometimes without telling anyone he had changed the locks.  He was a devotee of crossword puzzles, which he always completed in pen.  He was an avid hiker and backpacker who especially enjoyed the Anza-Borrego Desert State Park.  He is survived by his brother Stephen Daum, his wife Mea Daum, and his children Arwen "Emily" Daum and Nathan Daum.  Donations in lieu of flowers are suggested to the following: La Jolla Symphony & Chorus , the Home Depot Homer Fund , or the California State Parks Foundation .  A memorial service will be held Friday, March 1, at 4:00 pm in Rancho Bernardo at Hope United Methodist Church, 16550 Bernardo Heights Parkway, San Diego, CA 92128.