HISTORY - Page 50
and were especially preparing for the re-entry phase.
When the correct attitude was achieved, two spin
rockets the base of the body were activated to impart
a 60-rpm rotation to the body, and, upon attaining this
rate, nose cone separation occurred. No controls were
exercised on the nose cone after separation because
of the high Mach re-entry speed.
G&C was accomplished by an all-inertial system that
was based on the principle of constraining the missile
as closely as possible along a pre-calculated standard
trajectory. This work was done by a null-seeking
system that continuously compared actual expedience
data with that which had been precalculated. Then,
attempts were made to eliminate the errors by
gimballing the engine and signaling the main and
vernier cutoffs at the appropriate times. Total flight
time for the JUPITER for a maximum range firing was
1,016.9 seconds. At the end of 70 seconds from lift-off,
the missile experienced its maximum dynamic
pressure (13.69 G's) during the rise, and main engine
cutoff occurred at the end of 157.8 seconds at a speed
of Mach 13.04. Separation of the thrust unit and the
vernier start happened at 161.8 seconds, and vernier
cutoff was at 173.8 seconds. Nose cone separation
occurred at 339.3 seconds, and the nose cone reached
its zenith at 552 seconds. Re-entry began at 950
seconds (Mach 15.45) at about 100 km's in height, and
maximum dynamic pressure (44 G's) during the
descent was exerted at 980 seconds. Then, impact
occurred at the previously cited 1,016.9 seconds when
the aerodynamic drag had reduced the speed to Mach
0.49
64
.
_____________________________
64. Ibid.; See Appendix 5.