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Department of the Air Force Report, 1996

U.S. Department of War · 1996-09-10 · 181 pages · text from the file's own layer

This final report, dated September 10, 1996, was prepared by the Research Triangle Institute for the Department of the Air Force's 45th and 30th Space Wing safety offices. Titled Modeling Unlikely Space-Booster Failures in Risk Calculations, it shows how rare Mode-5 failures, in which a rocket veers well off its intended flight line, are modeled in the DAMP risk-analysis program. An appendix lists Atlas, Delta, Titan and Thor launch and failure histories through August 1996.

From the source:Release of 2026-05-08 Incident: 9/10/96, N/A. This report describes the Modeling of Unlikely Space-Booster Failures in Risk Calculations, documenting historical launch failure modes and recommending corrective actions to address them using novel modelling techniques.

  • p. 88 …Vehicle loses control at or shortly after liftoff, with all flight directions equally likely. Destruct is…
  • p. 106 …121 (8) Missiles/Space Vehicle Files, 45th Space Wing, Wing Safety, Mission Flight Control and Analysis…
  • p. 111 …Such behavior did not necessarily prevent the attainment of some, or even all, mission objectives. 50…
  • p. 131 …Due to excess speed, spacecraft passed 22,000 miles in front of moon, and primary mission…
  • p. 132 …Although Atlas performance was satisfactory, the mission was apparently a failure. No other data available. 134…
  • p. 133 …A flight-control malfunction occurred at about 15 seconds at the start of the pitch program…
  • p. 137 …Vehicle became unstable when B2 pitch control was lost at 121 seconds. Loss of pitch control…
  • p. 138 …The missile then lost attitude control, executing a hard yaw rate tum throughout and beyond the…
  • p. 139 …of the rate gyro or an electrical failure in the pitch channel of the flight control…
  • p. 140 caused yaw and roll rates that the flight control system could not correct. As a result…
  • p. 151 …Attitude control lost during second stage coast period. Third stage spun up, but did not fire…
  • p. 153 …One solid-rocket motor carried to MECO, but mission was still a complete success. 102. SMS…
  • p. 169 …Missile tumbled out of control at 130 seconds, then broke up. 104. IHA (65-210), 1…
  • p. 170 …Nominal mission through transtage second burn shutdown. Attitude control system engine failed to shutdown following vernier…
  • p. 171 …However, satellite propulsion system malfunctioned putting satellite in uncontrollable position with no possibility of restoring mission…
  • p. 172 …control until propellant depletion. Trajectory inaccuracies were compensated for during Stage-2 burn, and the mission…
  • p. 180 …Missiles/Space Vehicle Files, 45th Space Wing, Wing Safety, Mission Flight Control and Analysis (SEO), 1957…
5.3 Relative Probability of Tumble for Response-Modes 3 and 4
Exponential filters with values of F from 0.98 to 0.999 have been used to- estimate the
percentage of Mode-3 and Mode-4 •responses that tenninate with a thrusting tumble.
Results are given· in Table 18 for flight phases 0 - 2 and 0 - 5. For launch-area risk
calculations, only flight phases O- 2 are of interest. The data sample was a
chronological composite of all Atlas, Delta, Titan, and Thor tests and configurations
shown in Appendix D. To several decimal places at least, the values in the table are
determined entirely from Mode-4 responses, since the last vehicle to experience a
Mode-3 response (4/25/61) is weighted out of the solution: The results in Table 18 are
based ona total sample size of 1,186 flight tests.
Table 18. Percent of Response Modes 3 and 4 That Tumble .
Filter Factor Flight Phases O- 2 Flie.:ht Phases 0 - 5
0.999 25.0 25.0
0.996 26.3 27.0
0.993 27.3 28.6
0.990 28.3 30.1
0.980 31.3 34.8
Through flight phase 2, there were 33 tumbles out of a total of 132 Mode-3 and Mode-4
responses. Through flight phase 5, there were 42 tumbles out of 168 Mode-3 and
Mode-4 responses.
As seen from Table 13, the smaller the filter factor, the greater the weight placed on
recent test data. In view of this, it is apparent from Table 18 that the percentage of
Mode-4 responses that end with a thrusting tumble has been increasing gradually. The
same conclusion is reached for flight phases 0 - 2 and 0 - 5. In recognition of this
gradual increase, in future studies RTI will assume that approximately one-third of
Mode-3 and Mode-4 failure responses end with a thrusting tumble.
9/10/96 30

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Report, from the pursue collection. The PDF is mirrored here; the original link is under it. 181 pages are in the text index: search them above, or from the library's search.