A good illustration of a Mode-5 failure response occurred during launch of Prospector
(Joust) on the Eastern Range in-June 1991. The Joust consists of a single-stage Castor IV-A
solid-propellant rocket motor and a payload module. The "vehicle made a radical pitch-up
maneuver due to· aft-skirt structural failure at approximately T+14 Seconds." 121 The
vacuum instantaneous impact trace from the RSO console is shown in Figure 1. If the
safety officer had taken destruct action during the time interval from 18 to 25 seconds,
impact would have been well away from the flight line.

                                                                                     CYIER A
                 UNCLRSSIFIED                                                        IP "AP 1                  JOUST1761-R
                                                                r20SEC.
     +          3 □ .a                                                                                                          +        3 □.□
               RLTEP.                                       ..                                                                       PP.rttE
               I. 17B                                                                                                           CNH!AVE53
                SKIN
          ON TRRCK                                                                                           ...
                                                                                             . . . ..... ..._._:,.--25SEC.          ON TRACK
      1. D DELAY                                      ~•                                                                        1 .II DELAY
                                                      ',•            r1BSEC.                                    .::---,---

     +· 12 CHEV                                         ..
                                                       \"·./
                                                        t            •
                                                                                                           .
                                                                                                 ~ - • • • •30SEC.
                                                                                                       •
                                                                                                                                    15 CHEV
                                                                                 ■

          19.7 5LO
                                                            \
                                                                '\
                                                                         •
                                                                                               ....
                                                                                     . . . . . . ~-.


                                                                                                                                    16.3 !iLO
          32.2 SltT                                                                                                                 !II .1 5HT
           a. 1 RGT                                                                                                    15SEC.        Q.7 LFT
               ~-2 LOIi                                                                                                              ~    1 LOU
                                                                             \
                                                                                 \                                                       78 HDG
                                                                                                                                     625 VEL
                                                                                                                                          2 ALT

                                                  l
                                                  !
                              ....... -- ..
            D. I 1l
                .    --/ . --, ·- --•-=--.-,,,•'                                                                                CNTRAVE'i!
            SKIN . i             ·;
                I
          ON TRRU
      0 5 DELAY I
           0                                  .
                                              I
                                              '
                                                                                                                                 ON TRACK
                                                                                                                                0.5 DELAY
                          I               f i
                          i

                                                            +                4 GREEN

                   Figure 1. Joust Impact Trace Showing a Mode-5 Failure Response

As still another example of a Mode-5 failure response, a guided Red Tigress sounding
rocket was launched from Pad 20 at Cape Canaveral on 20 Aug 91. Within a second or
two after clearing the launcher, the rocket made a near 90° right tum, and flew stably in
this direction until destroyed by the safety officer at 23.3 seconds. Pieces impacted
some two or three miles from the launch pad. This failure might have been classified
as a Mode-2 response if destruct action had been taken·shortly after launch.



9/10/96                                                                                 6                                                         RTI