Mr. Hennen was the first Warrant Officer within the U.S. Army and Department of Defense to have been selected as a member of a NASA Space Shuttle flight crew.

This assignment was in direct support to the office of the Deputy Chief of Staff for Intelligence, Headquarters United States Air Forces in Europe.

He was the project officer for the Imagery Intelligence (IMINT) Tactical Exploitation of National Space Capabilities Program (TENCAP), responsible for developing all training requirements, concepts and doctrine.

His efforts culminated in the production of multimillion-dollar training programs which in turn supported the fielding of a variety of new systems operating at both the tactical and national intelligence levels.

Additionally, he participated in various Army, DOD, and National Intelligence Community working groups and subcommittees involved in TENCAP program activities.

Hennen was personally responsible for managing the development and successful fielding of state-of-the-art IMINT systems to both the European and Pacific theaters of operations.

Chief Hennen's efforts at ASPO were instrumental in the efficient evolution of five major TENCAP systems with a Life Cycle Cost in excess of 2 billion US dollars.

Hennen was selected on numerous occasions as Soldier and Non-Commissioned Officer (NCO) of the Quarter/Year by the various commands and agencies to which he was assigned during his enlisted career.