Documents / Report

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…
the differences in calculated Mode-5 risks for the different values of B would surely
have been less.
Further understanding of why small differences in Ee exist can be gained by plotting
values of the Mode-5 density function computed from Eq. (3) This has been done in
Figure 15 for a range of three miles using values of A and B from Table 21 for
qa. =5,000 deg-lb/ft2. Since Eq. (3) does not include a factor to account for the
probability of a Mode-5 failure, the values plotted in the figure are conditional impact
probabilities per square mile. For the sector from 120° to 180°, which is where most
population centers are located, the density-function value for B =5,000,000 is largest
and for B =1,000 is smallest. Results consistent with this are shown in Table 21, where
the largest and smallest Ec's are for B =5,000,000 and B =1,000, respectively.
~ ~ 00 00 1001~1~100100
Theta (deg)
Figure 15. Mode-5 Density-Function Values at Three Miles
6.2.3 Effects of Mode-5 Constants on Ship-Hit Contours
In the preceding section, certain values were assigned to Band, by trial and error, best-
fit values of A were found. For every breakup qa. and every B, it was possible to find a
value of A that produced good agreement between theoretical and simulated impact
data over 5° sectors from ±100° to ±180° (see Figure 10 through Figure 13). In some
9/10/96 51 RTI

Not linked to a story yet.

About this file

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.