Exploring the Unknown: Selected Documents in ... - The Black Vault

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First Steps into Space: Projects Mercury and Gemini
point, acquired a very good star pattern to maintain a celestial line of sight. Very
little motion was discerned during this period. The target-centered coordinate
plot indicated a flight path that was forward of and nearly parallel to the nominal
trajectory. At one point, the pilot stated that it appeared as if the target were go ing
up; however, the command pilot decided not to make any changes at that time.
At a range of 2 miles it again appeared from the pilot’s plot that the target was
going up a small amount, but there was no apparent motion in relation to the star
background. At 5 hours 46 min utes g.e.t., no relative motion was observable. The
range rate was approximately 42 ft/sec, and at 05:48:11 g.e.t., the target appeared
to start moving down a small amount but this relative motion was stopped. At
this point, the START COMP button was pressed. This caused all subsequent
changes in velocity to be displayed in cumu lative totals. At 05:49:06 g.e.t., both
the command pilot and the pilot noted that the reentry control system (RCS)
heater light came on at the telelight panel. This was at a range of 1 mile. This indicates
that the panel was observable to the crew during this crit ical period. The
total pitch angle, from 1.30 nautical miles into station keeping at 120 feet, was
approximately 125°.
7.1.2.3.4 Braking maneuver: During the terminal phase a combina tion of
radar display and optical tracking was utilized by the command pilot with the platform
continually in orbital rate. The target held steady on the indicator throughout the
terminal phase maneuver. At 05:49:41 g.e.t., the command pilot remarked that the
docking light was quite bright, and the pilot noted the same thing.
At 0.74 mile range (05:49:58 g.e.t.), the pilot noted that the tar get
appeared to be moving down. This comment was prompted as a result of seeing
sunlight reflected off frost particles leaving spacecraft 6 and confusing them with
stars. Spacecraft 6 was approaching the BEF attitude (spacecraft 6 was 30° beyond
the local vertical). The bal listic number of these particles was such that they
trailed the space craft, tending to move upward toward the nose of the spacecraft.
As the crew observed the frost particles, they appeared to go up in rela tion to
this apparent star field. There were stars still visible beyond these bright particles
and these stars confirmed that the target was not moving in relation to the stars.
This illusion for the pilot developed from the lighting conditions in the right
crew station. This side of the cockpit was lighted sufficiently to permit the pilot to
record data and work with the computer throughout this period. As a result, when
[7-24] he made an out-the-window observation, he could not see the stars, and
the particles appeared as stars to him. (This could have resulted in additional fuel
expenditures if both the command pilot and the pilot had reacted identically.)
At 0.48 mile range, the crew started decelerating spacecraft 6 from a closing
range rate of approximately 42 ft/sec. Dur ing this period, there appeared to be
no out-of-plane motion. As the braking continued, the velocity was reduced in a
continuous thrust. The command pilot peered behind the black shield on the
vernier scale until the pointer for range rate just appeared, having determined in
the train ing simulator that this represented approximately 7 ft/sec. At this point,
thrust was terminated and the range was approximately 1200 feet. The target had
dropped slightly and a downward thrust was also added. At 800 feet range, 32
minutes after the translation maneuver, the clos ing velocity was approximately 6
ft/sec and the IVI’s were cleared. The cumulative velocity changes at this point
read 27 ft/sec aft, 14 ft/sec left, and 7 ft/sec down.