to reasonable extremes that /g90/g82/g88/g79/g71/g3/g80/g76/g81/g76/g80/g76/g93/g72 clearance. For most of the 26 factors, those extremes were given by known tolerances. For the remaining factors, engineering judgment was used. This altered  baseline model would become our /g85/g72/g68/g86/g82/g81/g68/g69/g79/g72/g3 /g90/g82/g85/g86/g87/g16/g70/g68/g86/g72/g3 /g76/g81/g87/g72/g85/g73/g72/g85/g72/g81/g70/g72/g16/g69/g76/g68/g86/g72/g71/g3 /g80/g82/g71/g72/g79 , referred to  hereafter as the “worst case” model. /g3The team decided that a design solution was achieved if our ADAMS modeling efforts showed a minimum clearance of 6.4 mm (0.25 inch) between hard parts when running  the on-orbit version of this worst case model.   This approach was considered robust because it was highly improbable that all 26 factors would be  simultaneously biased towards minimum clearance in the actual flight hardware. Also, the HGAS ADAMS model had historically showed good correlation to the g-negated tests, especially in the first 15 degrees of  shoulder hinge rotation. As mentioned previously, the fidelity of the g-negation system to confidently test for interference of the gimbal with LRM C was insufficient due to the centering effect the gantry cable has on the HGAS during  ground testing. Therefore, this worst case ADAMS model represented the best tool available to vet this  issue. There is insufficient space to describe the kinematic role of all 26 factors in this worst case model, but the  three examples below demonstrate the typical methodologies used for biasing factors:  /g120/g54/g75/g82/g88/g79/g71/g72/g85/g3/g39/g72/g83/g79/g82/g92/g80/g72/g81/g87/g3/g54/g83/g85/g76/g81/g74/g3/g55/g82/g85/g84/g88/g72/g29 A higher value of the shoulder spring torque would lift the elbow  off the HGAS deck more quickly and thus further increase the interference of the gimbal assembly  with LRM C (see Figure 7). Since the model was already using spring torques measured off theactual flight shoulder spring, variances in those torques would be driven by the error in the torque transducer used to measure the springs. The claimed accuracy of said transducer was ±4%. Thus, it is possible for the measured torque to be up to 4% lower than the actual value. To be conservative on clearance in the worst case model, the torque vs. hinge angle curve for the shoulder deployment spring was multiplied by 1.04 (+4%) /g120/g40/g79/g69/g82/g90/g3/g39/g72/g83/g79/g82/g92/g80/g72/g81/g87/g3/g54/g83/g85/g76/g81/g74/g3/g55/g82/g85/g84/g88/g72/g29 Conversely, a lower value of elbow spring torque would result in a  slower lifting of the gimbal assembly off LRM C and thus reduce clearance/increase interference. As  with the shoulder, the model was already using spring torques measured off the actual flight elbow  spring. The same transducer was used to measure the flight elbow spring torque. In this case, we  wanted to minimize the spring torque in the worst case model to achieve the appropriate conservatism, so the elbow spring torque function was multiplied by 0.96 (-4%). /g120/g40/g79/g69/g82/g90/g3/g39/g68/g80/g83/g72/g85/g3/g55/g72/g80/g83/g72/g85/g68/g87/g88/g85/g72/g29  Viscous dampers are used at each of the hinges. Thus the damping  coefficients are functions of temperature. Decreasing temperature increases the damping. Heaters on  the dampers control there temperatures to 30 /g113C ± 2/g113C (86/g113F ± 3.6/g113F)  As previously noted, hindering  elbow rotation decreases clearance, thus the elbow damper temperature was set to 28 /g113C (82.4/g113F)  and the damping coefficient vs. hinge angular velocity curve in the model reflected the resulting  increase in damping. Both the baseline ADAMS model and the worst case model were used to determine the path forward.  Due to time constraints, the early runs that illuminated the potential issue were used to guide potential  hardware changes while the analysis team decided on the final conservative values for the aforementioned 26 critical factors of the worst case model. During this period, the baseline model was  used to study the effect of proposed hardware and flight operation changes. Model hinge angle results were incorporated into the CAD model to check actual clearances.  Issue Resolution The solution to the interference issue was a combination of adjusting the firing/release order of the three  launch restraint mechanisms (C then A/B became A/B then C) and trimming of non-deploying portions of the LRM C hardware to increase dynamic clearance. 55