He was assigned as a plumber at Shaw Air Force Base, South Carolina, where he was awarded as one of the 12 Outstanding Airmen of the Year for the Mission Support Group.

After commissioning, he underwent nine months of undergraduate space and missile training at Vandenberg Air Force Base, California.

From 1999 to 2002, he was assigned at Minot Air Force Base, North Dakota, where he moved back and forth from operational and instructor positions.

He then served a year as an ICBM senior instructor combat crew commander for the 91st Operations Support Squadron.

[1] In 2003, Middleton transferred to Alabama to serve as assistant professor of aerospace studies at AFROTC Detachment 015 at Tuskegee University.

He then served at the Office of the Secretary of the Air Force as deputy chief of the Senate liaison division.

[3] After serving as commander for two years, he was assigned to the Pentagon as a senior congressional advisor at the Office of the Chief of Space Operations.