Donald Brooks Longcope Jr. (Don) Don was born in Houston Texas on Monday, April 20, 1942 to Donald and Carolyn Longcope. He passed away at home on Friday, May 29, 2026. He attended Lamar High School where his dad was a basketball coach. Don was awarded All State in Basketball his senior year. He then attended Rice University, achieving a degree in Mechanical Engineering. From there he went to Stanford University for a masters degree. He took a position with Sandia Labs in Albuquerque in 1967. He took advantage of a program that Sandia offered to return to school for a PhD. He chose Stanford again, both for their excellent engineering department and for their famous golf course.

Don was an avid golfer and took advantage of the challenging course, where a misaligned shot might find you in raspberry brambles or scrub oak. On one occasion, after teeing off, he found his ball nestled in a herd of bright yellow banana slugs. Returning to Sandia Labs he researched, wrote and coauthored many scientific papers. His specialty was Computational Structural Mechanics.

Again, golf was a part of most weekends. He joined Tanoan Country Club when it opened and there he discovered the joy of playing tennis. Sports were to remain a large part of his life into his retirement. He is survived by his long time companion Linda Epstein, his son Travis (Sherry), granddaughter Kayla Polzun (Stephen), grandson Vincent, great grandchildren Robert, Christian, Riley, and Ethan. He is also survived by his ex wife and friend Karen Simmons.

A celebration of life will be held on Friday, June 5, 2026 - The Church of Jesus Christ of Latter Day Saints Eubank at 10:00am.