To remain consistent with prior NASA Goddard practice, torque resistances were updated using the more  conservative “Zero-Neutral” approach for characterization of the harnesses, wherein the net resistance is  the sum of the worst case deploying torque at beginning of rotation plus the worst-case stowing torque at  the end of rotation. The use of non-flight harness in tests also arose as an issue because of the natural  variability of wire geometry within their respective harnesses. Without photographic or other proof that the  original test harnesses were essentially the same, re-testing of freshly built flight-like harnesses was  mandated. This testing measured the actual harness route of the RDA and compared it to the test harness  that was built. The results of this testing showed that the test harness matched the behavior of the flight  harness. The “Zero-Neutral” approach changed the resistive torque of this harness from a resistive torque  value of 0.17 N-m (1.5 in-lb) used from the harness testing done in 2004 to 2.26 N-m (20 in-lb). The IPH1  hinge line harness resistance values were changed from 0.23 N-m (2.0 in-lb) to 0.76 N-m (6.7 in-lb), and  the IPH2 hinge line values were updated to 0.37 N-m (3.3 in-lb). The changes in these harness values and  applying the required factors of safety drove the torque margins to negative values reported in Table 2.  During the 2009 investigation on the characterization of the torque output of the hinges it was found that  the constant-torque springs were developing an unintended gap, shown in the right side of Figure 2. The  gap indicates excessive frictional loss in the spring stack. A wet lubricant, Braycote 601VB, was applied to  the both the roller and the spring stack to reduce friction and torque resistance. Additionally, the roller shaft  that should have been dry lubricated was found to be unprocessed, so a grease plate mixture of Braycote  601 VB and 30% molybdenum disulfide was applied to it. Despite the team’s best efforts, margins were still  negative, and it was too late to redesign, requiring the generation and processing of a waiver. In the waiver,  since the torque ratio was higher than 1.0, indicating there was driving torque above the minimum, the  negative margins were deemed acceptable based on the extensive and recent testing. This waiver was  presented to NASA in mid-August 2011 and the array was successfully integrated 2 days after the waiver  was approved, during final pre-shipment preparations.  Figure 2. Gapping in the Leaf Spring of the Main Deployment Hinge Testing the Solar Array  The testing flow for the components and assemblies in the S-NPP solar array was rigorous, starting at  component-level testing for mechanisms, release mechanisms, panel substrates and the solar cells prior  to and after attachment to the substrate. After these elements were assembled, the entire subassembly  went through pre-environmental testing, environmental testing, and then post-environmental testing. Preenvironmental testing included deployment testing, electrical testing, and Large Area Pulsed Solar  Simulator (LAPSS) testing. Environmental testing consisted of vibration testing and thermal vacuum testing  after which the pre-environmental testing sequence was repeated.  Figure 3 shows the S-NPP solar array when it was tested at the system level while attached to the satellite  and the arrangement of the gravity-negation ground support equipment (GSE)—also used for array testing  when not attached to the satellite. For hardware safety and GSE simplicity, all of the full deployment tests  of the S-NPP solar array were conducted on a separate test stand with the array removed from the RDA.  This subsystem-level deployment testing was a challenge throughout the S-NPP life cycle. The deployment  NASA/CP—2018-219887 392