Mueller was born in St. Maries, Idaho. His father was a logger and wanted Mueller to be one as well. Mueller compares his story to that of Homer Hickam, growing up in a hard-working family and going off to be an engineer instead of following in his father's footsteps. As a kid, he would build and fly Estesmodel rockets. He continued to experiment with rockets, even building one out of his father's oxy-acetylene welder and discovering adding water would produce more thrust. Mueller eventually became a logger, working four summers to pay his way through school. He attended the University of Idaho where he earned a bachelor's degree in mechanical engineering. He moved to California upon graduating, turning down job offers in Idaho and Oregon. He attended a job fair upon his arrival in California and began working in satellite design and moved on to developing liquid rocket engines. Mueller went on to attend Loyola Marymount University where he obtained his master's degree in Mechanical Engineering in 1992 from the Frank R. Seaver College of Science and Engineering.
Career
For 15 years, Mueller worked for TRW Inc., a conglomerate corporation involved in aerospace, automotive, credit reporting, and electronics. He managed the propulsion and combustion products department where he was responsible for liquid rocket engine development. He worked as a lead engineer during the development of the TR-106, a thrust hydrogen engine that was one of the most powerful engines ever at the time it was constructed. During his time at TRW, Mueller felt that his ideas were being lost in a diverse corporation and as a hobby he began to build his own engines. He would attach them to airframes and launch them in the Mojave Desert along with other members of the Reaction Research Society. In late 2001, Mueller began developing a liquid-fueled rocket engine in his garage and later moved his project to a friend's warehouse in 2002. His design was the largest amateur liquid-fuel rocket engine, weighing and producing of thrust. His work caught the attention of Elon Musk, PayPal co-founder and CEO of Tesla Inc., and in 2002 Mueller joined Musk as a founding employee of SpaceX. As Vice President of Propulsion Engineering and subsequently CTO of Propulsion at SpaceX, Mueller led the team that developed the Merlin 1A and Kestrel engines for the Falcon 1, the first liquid fueled orbital rocket launched by a private company; the Merlin 1C, Merlin 1D and MVac engines for the early iterations of the Falcon 9 launch vehicle; as well as the Draco thrusters that provide the attitude control thrusters for the Dragon spacecraft, as well as the SuperDracostorable-propellant engines used to power the capsule launch escape system. Dragon was the first spacecraft launched by a private company to dock at the International Space Station. In 2014, Mueller transitioned engine development to the SpaceX Propulsion Engineering team and in 2016 he moved into the Propulsion CTO role. In January 2019 he became Senior Advisor. Outside his work at SpaceX, he was a commencement speaker for Loyola Marymount University graduate students in 2013, the year after SpaceX became the first private company to send a cargo payload to the International Space Station. He was also the feature of an article called "Rocket Man," published by LMU Magazine in 2011. In 2014, Mueller was nominated for the Wyld Award, presented by the American Institute of Aeronautics and Astronautics for outstanding achievement in the development or application of rocket propulsion systems.
