Attention is given to the definition of the on-orbit dynamic testing that is currently being planned for the flight of a large solar array test article, the Solar Array Flight Experiment (SAFE 1), which consists of a coilable longeron mast that deploys a large solar array blanket. Also discussed is the design of an additional experiment employing this structure in conjunction with a two- or three-axis gimbal system, in order to demonstrate control techniques applicable to such large structures. SAFE 1 experiment objectives, hardware, software, and the experimental operations foreseen are discussed.