325 the bearings was exonerated by measuring the hardness of a set of bearings from the same lot as the  bearings in the EM unit . Tests resulted in an  average hardness of 57.6 on the Rockwell Hardness Scale C  (HRC), which was considered in- family with the specified requirement of 58- 60 for the 440C stainless steel  bearings .   Bearing analysis via Orbis 3.0 indicated that an angular misalignment of 0.00028 in (7 µm) could introduce  localized Maximum Mean Hertzian Contact Stress (MMHCS) greater than 335 ksi  (2310 MPa) . Both a  coordinate measuring machine (CMM) and computed tomography  (CT) (Figure 11) scans were used to  evaluate this condition. CMM measurements showed a 0.0004- in (10-µm) difference across the bearing  diameter while computerized tomography ( CT) scans did not show any signs of misalignment. However,  the CT scans only had a voxel resolution of 0.002 in (51 µm) , which is not fine enough to detect the potential  misalignment. The CMM measurements could only be made on the SCS secondary mirror attached to the  output shaft. The ali gnment was only considered conditionally exonerated until the bearings could be  inspected after a tear -down procedure on the EM unit.   Quality issues with the bearing could include (but are not  limited to) poor workmanship, damaged components, or  out-of-specification material . A review was conducted of all  quality systems involved with the procurement, assembly,  and testing of the bearings . Contingent on future  disassembly and inspection, the bearing quality was  believed to be adequate.   Poorly designed clamp rings or uncontrolled tolerance  stack- ups between inner and outer bearing ring spacers  in  the output bearing assembly could result in Brinelling  behavior . Manufacturing errors on bearing ring spacers  could reduce preload  and result in gapping during test  events which could also damage the races . Either result  could create the observed torque spikes . All inspection  points and assembly measurements were review ed to  confirm that the as -built tolerance stack -up was nominal .  Shimming and grinding procedures were confirmed to  produce the desired preload, which was measured  indirectly (by measuring the gap between the clamp and  shaft/hub)  during assembly of the bear ings. Review of the  clamp design analysis with a high- fidelity  Finite Element  Analysis (FEA) model confirmed good correlation with the  load vs. deflection curves seen in in the as -built assembly.  Bearing set running torque was measured during assembly  and aligns closely with values predicted in Orbis . Axial  acceleration endured by the bearing set during Protoflight  vibration testing was measured to be 30% less than predicted, indicating additional overhead on bearing  design safety factors . Status  of manufac turing errors as the root  cause is labeled as Conditionally  Exonerated until the bearing set c an be disassembled,  allowing for closer inspection and more precise  measurement  (disassembly of the EM bearing assembly has not occurred at this time) .  Over -testing of the bearings could of course impart greater loads on the bearings than their design intended.  A detailed review of all test parameters and instrumentation was conducted in relation to the Environmental  Requirements Document (ERD). The review concluded that all parameters adhered correctly to the ERD  and all measurements were taken with calibrated instruments. This cause was exonerated.   The analysis performed to generate the bearing design was conditionally implicated in causing the bearing  torque spik es. Analysis was performed with three different suites of specialized bearing software (Bearings   Figure 11. CT scan of output bearing  assembly