He was born December 31, 1921 in Timewell, Illinois the son of William R. and Ruth Bell Heathman Mullen. On July 22, 1945 he married Bette J. Rossiter in Cheyenne, Wyoming. She survives.

He was a 1940 graduate of Quincy High School and served in the US Army Air Corps during WWII from 1940-1945 where he rose to the rank of Staff Sergeant . He received three bronze battle stars for campaigns in Northern France and Germany. He was a fighter aircraft mechanic and instructor. Robert was instrumental in the development of the P51 Mustang. After the service he became an aircraft mechanic for United Airlines in Cheyenne, Wyoming. He moved back to Illinois and attended Quincy College for two years before transferring to Bradley University in Peoria. He graduated with a B. S. in Mechanical Engineering, and then worked as a foreman for Burgess Norton in Geneva, Illinois. He then worked for Westinghouse Electric Corp. where he was employed for 28 years until his retirement in 1984. After retirement he stayed with Westinghouse as a consultant. During his years at Westinghouse he worked and traveled internationally including Mexico, Bermuda, Poland, Yugoslavia, Saudi Arabia, the Philippines, Taiwan and India.

Robert was on the Board of Trustees and was the Fire and Police Commissioner of Sauk Village, IL. He was also a Scout Leader. In Quincy he was a member of the Golden K. Kiwanis, Mississippi Valley Historical Car Museum, and the Antique Car Club. He volunteered for RSVP and at the Villa Kathrine where he provided information to tourists. He was a member of Melrose Chapel United Methodist Church.

Survivors also include 5 sons, James R. Mullen of Crete, IL, Patrick M. Mullen of Niles, MI, William R. Mullen of Steger, IL, Barry E. Mullen of Crete, IL, Christopher R. Mullen and wife Tammy of Enterprise, AL; 9 grandchildren; 4 great grandchildren; a sister, Edra Fusselman of Vidor, TX; a brother, Duane R. Mullen and wife Mary of Orange Park, FL, and several nieces and nephews. He was preceded in death by his parents, a brother Doyle and a sister Betty Ruth Pace.

Fuenral Services: Saturday, January 26, 2008, at 2:00 pm in Hansen-Spear Funeral Home with the Rev. Scott Swigart officiating Burial will be in Greenmount Cemetery.

Visitation: Friday from 4-7 pm. at Hansen-Spear Funeral Home

Memorials: Paralyzed Veterans of America.