Mich. Comp. Laws § 259.782

Sec. 2. This act does not apply to the design, construction, production, maintenance, launch, flight, test, operation or use of, or any other activity in connection with a model rocket or model rocket engine, when carried on or engaged in by (a) the United States or this state, (b) a college, university or other institution of higher education, or (c) an individual or an entity engaged in research, development or production of rockets, rocket engines or propellants, or components thereof, as a business.