form factor. The geometry of this antenna system is shown in Figure 1 with the four petals shown in the  deployed state. Here the co-planer petals are shown in green, and the desired stowage volume of 10x10x20  cm is shown in purple. The remaining 6U CubeSat volume is identified with a semi-transparent box.  Structurally, the deployed petals needed to maintain a stiffness requirement above 0.5 Hz, a lateral  precision of ±4 in (±10 cm) at the petal distal edge and a twist precision of 1 in (2.5 cm) measured with  respect to the top/bottom of the outer ends. It was found that the simplest approach was to wrap the four  petals around a central hub and utilize strain energy to deploy upon the release of a circumferential  restraining band. The petals, consisting primarily of a copper to enable RF performance, were reinforced  with high strain composite lamina to control the stowed strain energy and deployment dynamics. The added  lamina also protected the metallic RF element while stowed, assist the deployment and finally to improve  the deployed structural performance. In a recent publication [7], the end-to-end development process of the  petal design is discussed at length; this includes the architectural trades, laminate fabrication, early  challenges such as delamination and creep effects, and finally the integration efforts of this system into the  spacecraft deployment mechanism. This current paper focuses on the mechanism specific design aspects  of this system that secured, exposed and triggered the petal radial deployment within the CubeSat form  factor. Challenges in design as well as lessons learned during initial fabrication and flight qualification are  detailed at length as well as the challenges of integrating high strain composite deployables.   Figure 1. Basic geometry of deployed CubeSat antenna  Architectural Trade & Mechanical Design  The challenge of deploying a series of large, furled flat panels within a small CubeSat form factor was  broken down into several targeted areas for the Roccor team to work through. The first consisted of  designing a laminate that could withstand the high strains while stowed, ensure sufficient energy for a robust  deployment and finally provide adequate stiffness and precision once exposed. Important considerations  such as defining the furled geometry of the petals were a central focus, especially in the transition region  between the furled panels and the central petal supporting structure. The second category focused on the  mechanics for how to stow, package and protect the furled petals within the CubeSat volume during launch,  and upon activation, release the petals in the space environment. This area had the added complexity of  physically moving the stowed petals from the cocooned volume to the outside of the spacecraft prior to  petal unfurling. In addition, the deployment synchronization and analysis of the petal unfurling were prime  focus areas within this group. The final category consisted of the electrical considerations such as the  incorporation of the actuation device, integration of the RF electronics, wire harness management and  finally, providing sensory feedback indicating a successful deployment.  Petal Laminate Design  The first step in the design of the petal, was to define the key geometric constraints imparted by the CubeSat  envelope and central hub structure. This latter component, supplied by the payload provider, consisted of  two interlocking plates forming a cross, with each of the petals bonded to the exposed outboard surfaces.  NASA/CP—2018-219887 338