Horst Rudolf Mellenberg, 78, of Stafford County passed away Friday, October 25, 2019 after a short illness at Mary Washington Hospital. Mr. Mellenberg was born on June 20, 1941 in Dramburg, Germany to Adele Janavicius and Rudolf Adolf Mellenberg. He graduated from Anacostia High School in 1959 and went on to earn his BS of Engineering from the University of Maryland and his Masters of Engineering from Virginia Tech. Mr. Mellenberg worked for 40 years as Program Manager for various projects with Computer Sciences Corporation. He was a member of the University of Maryland Alumni, University of Virginia Tech Alumni and IEEE. Mr. Mellenberg enjoyed fixing cars in his spare time. Survivors include his wife Kathleen Mellenberg of Stafford; children Erik Mellenberg of Seattle, Washington, Kevin Mellenberg of Columbus, Georgia, John Powers, Jr. of Pottsville, Pennsylvania; Kevin Powers of Ashburn, and Janet Powers of Pottsville, Pennsylvania; grandchildren Jackson, Michael, Hutch, Wesley, Carly, Davis, Patrick, Dylan, Jake, Anna, Leah, Emma, and Caitlin; and sisters Heidi Sanford, Adele Hoofnagle, Lilli Wray, and Rita Quigley. The family will receive friends from 4 to 6 p.m. on Sunday, November 3 and from 9 to 10 a.m. on Monday, November 4 at Covenant Funeral Service, Stafford. A Mass of Christian Burial will be held at 11 a.m. on Monday, November 4 at St. William of York. A reception will follow the service at Knights of Columbus. In lieu of flowers, donations may be made to Little Sisters of the Poor, 1503 Michaels Road, Henrico, Virginia 23229-4822. Online guestbook is available at covenantfuneralservice.com.