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. •

               Table 21 . Sha:,mg
                               • Constants and R 1 eaet d Risks for Atlas HAS
                       TB        Breakup qa:·                            Mode-5 Ee
            Ps       (sec)       (deg-lb/ft2)       B           A          (x 10-6)
         0.005        118          14,000 *       1,000       3.00          227
                                  (baseline)
         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