the root due to the clearance trimming was calculated to be 13.3 mN-m. Deployment torque for the  untrimmed tape spring is approximately 48.5 mN-m.   Deployment Testing The assembled prototype unit is shown in the deployed and stowed configurations in Figure 12. The  membrane was cut from 50.8- /g80m (0.002-inch) thick Kapton using a Gerber ply cutting table. This  thickness is approximately 3x that of the anticipated operational material. The positioning lanyards were  constructed from braided Spectra cord. The ends were bonded to steel spheres with a hole drilled  through the centroid. The membrane was folded in a conical coffee-filter-type fold pattern and guided into the containment shroud located with the tape spring members. Minus the base plate, which was intentionally oversized for testing purposes, the assembled system mass was 113 g.  The initial functional deployment test of the fully assembled structure shown in Figure 12 did not finish in  the fully deployed configuration. High-speed video shows the booms would fully deploy, but the shock  loading at full deployment caused buckling in the members, at which there was insufficient torque from the boom tape spring members to overcome the compressive load and fully lock out. Manual assistance was given to fully deploy the boom tape springs, which confirmed the system’s integrity in the deployed configuration. The boom tape springs were then perturbed to induce buckling and observe the response quasi-statically. The booms did not have sufficient torque to return to the locked state. Original  deployment torque calculations did not include parasitic torques from bearing and side shroud friction, or  gravitational loading. Preliminary deployment testing without the position control lanyards was successful  with no failures observed. Gravity offload support to negate the top frame mechanism mass was included for subsequent testing. The relatively small mass of the corner fixture, coupled with the large vertical deployment distance of 0.26 m, presents a challenge to not overly influence the true dynamics of the deployable structure with a passive offload system. Each top frame fixture was connected to a series of  extensional springs with and effective stiffness of 0.28 N/m. The spring ends were connected to a common point approximately 12 m above the test article. Braided Spectra cord was used to connect the springs to the frame fixtures. This height resulted in a negligible parasitic lateral load of approximately 3% of the vertical offload force of 0.19 N. The deviation of vertical offload force from the stowed to the deployed state was roughly 0.07 N (37%). The top frame assembly was disconnected and supported by  the offload lines. The height of the upper offload point was adjusted until the top frame was offset at the nominal distance from the base plate. Therefore, the offload system provides additional deployment  assistance at the beginning of deployment. The high deployment rate observed in preliminary testing  showed sufficient deployment torque was present and the additional force from the offload system was not enabling a deployment that would otherwise fail. After assembly in the deployed state, the booms were manually buckled and returned to the locked state as desired. Eight deployment tests were performed on the updated test article to demonstrate the feasibility of the  novel structure design. Deployments were considered successful if all tape springs fully transitioned to the deployed state and lanyards tensioned as shown in Figure 12. Three attempts resulted in deployment  failure, which was due to lanyard snagging on the deployment mechanism. Lanyard control features were  not implemented during the first round of testing in order to minimize the effort required to demonstrate  deployment feasibility. The membrane containment shroud was redesigned with features to stow the lanyards and provide a more deterministic method to deploy without catching on the mechanism. Four additional deployments were performed with no failures observed. Selected captured images from a  successful deployment are presented in Figure 13. The deployment duration was approximately  0.65 second. Deployments were initiated immediately after stowage, such that any torque degradation due to stress relaxation was insignificant. Visual inspection of the tape springs did not reveal any noticeable damage.  507