around each spin rate measurement, meaning that there was a 99.9% chance that the true spin rate was  within 0.6% of the value calculated.  

By summing the effects of these test ing error sources, the model spin  rate was reduced by 7.35%. This  reduced the average measurement vers us model discrepancy to 6.0%.  

Table 2.  Spin Rate Measurements in Zero-Grav ity versus Each Model for All Deploy ment Trials  

Trial Test Configuration Zero-G Spin Rates (RPM) Zero-G Spin Rates (RPM)     Using Original Model Using Corrected Model  Number Flip Temp Deploy Model % Diff Deploy Model % Diff            1 Back Ambient 29.07 32.37 -10.18 29.05 29.99 -3.13  2 Back Hot 27.77 32.37 -14.20 27.77 29.99 -7.40  3 Back Cold 27.83 32.37 -14.03 27.83 29.99 -7.21  4 Front Ambient 28.17 32.37 -12.97 28.17 29.99 -6.07  5 Front Hot 27.43 32.37 -15.25 27.43 29.99 -8.53  6 Front Cold 28.95 32.37 -10.55 28.95 29.99 -3.45 

The zero-g spin rates for each deploy are compared to the original model and the corrected model in  Table 2. After this model correcti on, all deploys had spin rates within 10% of expected values. Thus, the  primary goal of the qualification depl oyment testing was satisfied.  

For completeness, friction in the flight mechanism s was analyzed to try to explain the remaining 6%  discrepancy. Testing on the pusher showed that dimpli ng sustained during vibration testing (even on the  harder SS pusher tip) made it more difficult for the ro ller ball to turn and thus caused increased friction in  the pusher housing. This resulted in about a 2.5% lo ss of spin rate. Testing on the bushings in the XY  and XYZ mechanisms showed that friction there resulted in about a 0.5% loss of spin rate. Neither of  these friction sources was significant ly affected by the presence of grav ity and this 3% loss is likely to  occur during flight. The remaining 3% discrepancy c ould not be explained by friction and is most likely  due to additional modeling errors resulting from imperfect test conditions.  

Tip Off Angle Methods and Results.   The second goal of this qualification deployment testi ng was to show the spacecraft had a tip-off angle of  less than 10 deg when it moved beyond the deployer stanchions for all flip cases and temperature  conditions. Tip-off angles were calculated by compari ng the relative movement of photo targets on tabs  extending from the front and rear decks of the ETU.  

The camera parallax correction was extremely important  for this calculation because targets were located  at different distances from the camera. To account  for this, equations (4) and (5) had to be modified by  changing the 81 on top of the fraction to 92, which was t he distance in inches from the camera to the rear  deck.  This correct ion was much less dramat ic for the spin rate calculations, where correcting for parallax  changed the results by only 0.5%.  

The measured tip-off angles for each deployment are shown in Table 3. The average tip-off angle was  5.9 deg and the largest value was 7.7 deg. All of the measured tip-off angles were less than 10 deg and  therefore the second goal of depl oyment testing was met.   

Table 3.  Tip-Off Angle Measurements for all Trials   Test Configuration Tip-Off Angle Trial Flip Conditions      (Deg)       1 Back Ambient 3.6  2 Back Hot 4.4  3 Back Cold 7.7  70