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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…
F =0.98. The conditional probability of a Mode-5 response was assumed to be 0.08
(from the last line of Table 15), so the absolute probability was 0.031 x 0.08 = 0.0025.
For the remaining cases in Table 21, the same assumptions were made for the total
failure probability and for the probability of a Mode-5 response. •
a:,mgTable 21.Sh • Constants and R 1eaet d Risks for Atlas HAS
Ps
TB
(sec)
Breakup qa:·
(deg-lb/ft2) B A
Mode-5 Ee
(x 10-6)
0.005 118 14,000 * 1,000
(baseline)
3.00 227
0.0025 280 14,000 * 1,000 3.00 49.1
(new P. & T..)
0.0025 280 . none 1,000 1.90 139.8
20,000 2.75 73.7
10,000 3.20 33.4
5,000 3.45 19.8
0.0025 280 none 50,000 3.15 144;9
20,000 4.10 75.6
10,000 4.50 37.1
5,000 4.75 21.8
0.0025 280 none 100,000 3.40 144.8
20,000 4.30 79.8
10,000 4.75 36.1
5,000 5.00 21.1
0.0025 280 none 500,000 4.00 143.6
20,000 4.85 79.9
10,000 5.30 35.9
5,000 5.55 20.8
0.0025 280 none 5,000,000 4.75 144.8
20,000 5.65 77.7
10,000 6.10 34.2
5,000 6.30 22.0
* Interpolated from Figure 14
As seen from Table 21, the Mode-5 risks are highly dependent on A and insensitive to
the value chosen for B provided a proper choice is made for A. Even for values of B as
different as 1,000 and 5,000,000, the Mode-5 risks (qa =5,000) differ by only 12%. This
difference drops for all other values of B. In fact, the differences probably have more to
do with the choice of A than to any inherent difference in results due to the choice of B.
For Atlas IIAS, 24% of the total Mode-5 Ee in the launch area is due to one population
center, and 51 % of the total Ee to only five population centers (see page 49 of Ref [3]). If
values of A had been chosen so that theoretical distributions and random-attitude-turn
distributions more nearly matched for the radial directions to these population centers,
9/10/96 50 RTI

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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.