Miller was born in Newburgh, New York.^[1] His mother, a single mom, is a New York City school teacher. He originally planned to enter the United States Air Force Academy, but upon visiting the campus, he felt he preferred "a little more of the traditional 'college' experience." His sister, a sophomore at Lafayette College at Easton, Pennsylvania, convinced him to enter Lafayette.^[2]

Miller received a B.A. degree in anthropology and sociology in 1993 from Lafayette. He then earned an M.B.A. with honors in 1997 from Regis University at Denver, Colorado. He also received a Master of National Security and Strategic Studies in 2005 from the Naval War College, a Master of Airpower Arts and Science in 2006 from the School of Advanced Air and Space Studies, and an M.S. in national security strategy in 2013 from the National War College.^[3]

Miller also attended Squadron Officer School, Air Command and Staff College, USAF Weapons School, and Air War College. He also participated in leadership programs and seminars from the Center for Creative Leadership, Alan Freed Associates, and Institute for Defense Business.^[3]

Miller was commissioned into the United States Air Force on May 29, 1993. After commissioning he served as a Gold Bar Recruiter in Rutgers University at New Brunswick, New Jersey with the Air Force Reserve Officer Training Corps Detachment 48. After that, he went to undergraduate missile training at Vandenberg Air Force Base, California. He finished the training as an outstanding performer.^[3]

After undergraduate missile training, Miller was assigned to his first operational assignment at Francis E. Warren Air Force Base, Wyoming, as an Intercontinental Ballistic Missile (ICBM) operator, instructor, and senior standardization and evaluation crew commander with the 321st Missile Squadron. He stayed there for four years until he shifted to the space operations career field. From 1998 to 2000, he served as weapons and tactical flight commander of the 2nd Space Warning Squadron at Buckley Air Force Base, Colorado. After that, he was assigned as executive officer with the 21st Operations Group at Peterson Air Force Base, Colorado, for over a year.^[3]

After graduating from Weapons School, Miller was reassigned with the 21st Operations Group as chief of weapons and tactics. From 2002 to 2005, he was assigned at Hickam Air Force Base, Hawaii, as chief of strategy plans of the Pacific Air Forces (PACAF) Air Operations Center and legislative liaison with the PACAF commander's action group. After that tour, he went back to the United States to study for two years, first at the College of Naval Command and Staff and then at the School of Advanced Air and Space Studies.^[3]

From 2007 to 2008, Miller was stationed at the Pentagon as chief of the Space Control Division of the Air Force. Afterwards, he was assigned back to Vandenberg as chief of the Combat Operations Division at the 614th Air Operations Center and Joint Space Operations Center. He then went on to command 2nd Range Operations Squadron from 2009 to 2011, in charge of launch operations for the 30th Space Wing.^[3]

Miller was reassigned to the Pentagon in 2011 as a military assistant to Erin C. Conaton, who at that time was serving as the under secretary of the Air Force. After graduating from the National War College, he went back with the 21st Operations Group, now serving as commander. He commanded the 21st Operations Group from 2013 to 2015. After his second command tour, he was stationed to Iraq as a senior advisor to the Prime Minister’s Office and Ministry of Interior.^[3]

In 2016, Miller took command of the 460th Space Wing, where he was in charge of the Air Force's missile warning unit.^[4] He served as commander for two years, after which he was reassigned as director of plans, programs, and financial management with the Air Force Space Command (AFSPC) at Peterson Air Force Base. While at AFSPC, he was promoted to brigadier general in 2018. He was tapped by General John W. Raymond to lead a task force on conducting detailed planning and implementation for the reestablishment of the United States Space Command.^[5][3]

In January 2020, Miller was assigned as senior military assistant to the Secretary of the Air Force Barbara Barrett.^[6] He served in this position for a year, after which he was reassigned as the first assistant deputy chief of space operations for operations, cyber, and nuclear. Six months later, he moved back to Peterson Air Force Base as director of operations, training, and force development of the United States Air Force.^[3]

In April 2021, Miller was nominated for transfer to the United States Space Force and promotion to major general. He was one of the very first Air Force general officers who transferred to the Space Force. He was also one of the first three major generals in the service among, Major General DeAnna Burt and Major General Douglas Schiess.^[7][8]

In September 2023, Miller was nominated for promotion to lieutenant general and assignment as commander of Space Operations Command (SpOC). He would replace Lieutenant General Stephen Whiting who was selected to serve as commander of the United States Space Command. His nomination was among the hundreds of military nominations stalled by Senator Tommy Tuberville's hold over the Pentagon's abortion policy. While he waited for confirmation, he was temporarily assigned as special assistant to the vice chief of space operations while stationed at Peterson. His nomination was confirmed on December 5, 2023.^[9][10] On January 9, 2024, he was promoted to lieutenant general and took command of SpOC.^[11] As SpOC commander, he is responsible for the generation, presentation, and sustainment of Space Force operational forces.^[3]

Miller is the recipient of the following awards:^[3]

• With Kathryn M. G. Boehlefeld and James Wood Forsyth Jr. (Winter 2023). "Ten Propositions Regarding Nuclear Weapons Detterence" (PDF). Æther: A Journal of Strategic Airpower & Spacepower. 2 (4): 22–35.

• Appearances on C-SPAN