Each Micro Propulsion Attitude Control System (MPACS) tube underwent testing prior to assembly and launch. The first tests for MPACS occurred on 10 and 13 May 2004. These tests involve firing each tube and documenting how many pulses are observed. However, there are no details to exactly which PPT was fired, so from this point in the analysis, the most conservative (longest) duration will be assumed to be for the PPT that shorted on 2 Nov 07 (PPT Cluster 2, Tube 2). Additionally, since there are no time records available, a frequency of 1 Hz will be assumed. This comes from long term testing on different tubes that showed a variation of frequency, with 1 Hz being the lower range.
On 10 May, the maximum number of pulses was 40. Assuming the conservative estimate of 1 Hz firing, this gives 40 seconds. Using the same logic, the maximum of 60 pulses on 13 May adds another 60 seconds. In total, all the documentation from the USAFA clean room shows a maximum time of 100 seconds.
The next series of tests occurred at Kirtland AFB, NM on 17-26 April 2006. This included the Hot Bake Out and Hot Start test and the Cold Soak and Cold Start test three times each for a total of 6 tests. The procedures called for firing each tube only 5 times, however the actual results varied. The total duration of these six tests was 120 seconds at most.
The last series of test occurred on 6 June 2006. This test involved testing MPACS in a cold environment (0 deg C). The documentation was much better with this test, having 12 pulses specifically counted for the tube of interest. However, there are no remarks as to a second part of the test in which one of the +X MPACS (Cluster 2) fired for an additional 42 pulses. Assuming this was tube 2, the maximum time tube two fired was 60 seconds.
Adding each series of the test campaign gives a total of 280 seconds. A summary is shown in Table 1 below.
The flight model was tested for functionality on 9 and 10 May 07. The test consisted on turning on each tube between 15 and 66 seconds and watching the telemetry in the current line to the MPACS clusters (satellite 9V current line) as well as the main and trigger capacitor values. Upon first glance, due to the sampling rate being set at 15 seconds and only one data point being observed for each point, the test seemed to show all tubes worked. This can be shown in Figure A-1 in Appendix A, where 5 tubes were tested. Additionally, the...