Reversing the LRM release order improved the originally predicted 1.0-mm (0.04-inch) interference to 12  mm (0.46 inch) of clearance in the baseline model. With C firing first, followed by A/B four seconds later (i.e. the original firing order), the ADAMS model predicted that the retractor impact and kick-off spring energy at C was mostly absorbed by the x-axis gimbal actuator, contributing nothing to separating the HGAS from the surrounding structure. With the firing order reversed (A/B followed by C four seconds later), the model predicted that the firing of A and B does not change the hinge geometry significantly as  the structure is still held down at C. But when LRM C is finally fired, the retractor and kick-off spring  energy are efficiently used to rotate the HGAS away from the other structures about the elbow hinge axis. This operational change was implemented in the on-orbit deployment commands through the GPM engineering change request system. It was successfully utilized on all subsequent ground deployment tests. Although the baseline model predicted 12 mm (0.46 inch) of clearance, the criterion for a successful  design solution was 6.35 mm (0.25 inch) of predicted minimum clearance from the on-orbit version of the  worst case model. A quick model run, assuming only one of the 26 factors biased towards interference  (i.e. retractors transferring no impact energy to the booms), brought the predicted clearance back down to  4.8 mm (0.19 inch). A similar run with the worst case model was not done as the clearance was already  below the target minimum. This necessitated trimming LRM C’s tower assembly.  Figure 10 provides an overview of LRM C and the related constraint components. The spherical tower assembly of LRM C was nearest to the outboard actuator and was the locationof predicted interference.  The most direct solution was to remove  the corner material of each component in the tower assembly. At this stage of GPM testing and integration, HGAS had completed subsystem environmental  test verification and had been delivered and integrated to the flight spacecraft. Thus modifying the test-verified  hardware could create a programmatic risk by nullifying the test verification.  However, spacecraft environmental  testing had not yet begun and it was deemed that modification of constraint components would not violate previous verification so long as load path and contact stress were not compromised. Workmanship for reassembly would be verified through spacecraft-level environmental  testing. Removal of tower component corner material up, to but shy of, the constraint contact region meant the removal of two tower assembly fasteners. Sub-assembly finite element analysis was performed  with this change in place and yielded an acceptable margin.   Modification of the constraint tower assembly components required tower assembly removal from HGAS. As the tower was pinned to the HGAS deck and already qualified, the decision was made to modify the  installed components rather than flight spares. Positional relocation was not then a concern. Figure 11illustrates the component modifications performed to ensure the desired deployment clearances.Figure 10. LRM-C Constraint Component Assembly 56