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FINAL PREPARATIONS: 1968
Mission Planning and Operations, 1968
Site evaluation continued throughout 1968, with considerable attention
given to reducing the number of potential landing sites being
considered. Keeping five sites as alternatives created problems in
providing the necessary maps, photographs, and terrain models for the
simulators. On the other hand, until the team at the Cape could be sure
of on-time launches, alternate sites had to be kept in the plans to
avoid a month's delay in launching a mission.80
Experience alone would answer many of the critical questions, and in the
last half of 1968 some very important experience was gained. By early
fall the reworked command and service module was ready for an
earth-orbital test. The 11-day flight of Apollo 7 (October
11-22) was successful in all respects, demonstrating the performance of
spacecraft, crew, and mission support facilities in extended
earth-orbital flight. Among other critical activities, the crew
simulated rendezvous with the S-IVB stage (which would carry the lunar
module on a lunar landing mission) and fired the service module engine
eight times without failure. That was especially gratifying, because if
that engine failed the spacecraft could neither enter lunar orbit for a
lunar landing nor return from lunar orbit after completing a landing
mission.81
Even before Apollo 7 flew, project officials made one of
the more daring decisions of the entire program: to send a crew to orbit
the moon on the first manned flight of the Saturn V. Planners had long
felt the need for such a mission to verify communications and navigation
at lunar distances. In the alphabetical scheme of flights. [see Chapter 7] the "E" (fifth)
mission was to approximate these conditions in high earth orbit. In
August, MSC Apollo manager George Low set his people to work plans to
extend the flight to lunar orbit. In a week of intensive discussions no
"show-stoppers" emerged, and neither Marshall nor Kennedy
Space Center officials expressed any reservations about it. By
mid-month, Houston had clearance from Headquarters to prepare for a
"C-prime" mission, contingent on successful qualification of
the spacecraft on Apollo 7. The lunar flight, to be designated Apollo 8,
would take a manned command and service module into orbit around the
moon, check out critical systems at lunar distances, and return.82
It had to be done sooner or later, and as more than one official
mentioned during the planning discussions, it was essential to assuring
a successful lunar landing by the end of 1969. Yet the decision to send
men to the moon on the Saturn V's third flight seems almost
breathtaking. The flight record of the big booster at the time (two
flights, one completely successful, the other plagued by malfunctions)
was enough to give managers pause; and the risks to be taken on a lunar
mission were far more serious than those of an earth-orbital mission.
Still, among NASA officials and Apollo contractor executives, no serious
doubts were raised about sending Apollo 8 to the moon at the end of
1968.83
The first men ever to see the moon at close range, Frank Borman, James
A. Lovell, Jr., and William A. Anders, left Launch Complex 39A at
Kennedy Space Center early in the morning of December 21, 1968, aboard
Apollo command module 103. Four days later they fired their main
propulsion engine and the spacecraft became a captive of the moon's
gravity, in an elliptical orbit which they later changed to a
near-circular orbit 60 nautical miles (111 kilometers) above the
surface. For the next 20 hours they took photographs, relayed their
visual observations and descriptions of the topography back to Mission
Control, and gave viewers on Earth spectacular television views of the
moon and of their home planet. On Christmas day in the early morning, at
the end of the 10th trip around the moon, they fired the service module
engine once more to return to Earth. The success of this maneuver
prompted Lovell to notify Houston, "Please be informed there is a
Santa Claus."84 Had it failed, he
and his crewmates would have remained where they were, circling the moon
until their oxygen ran out.
The space program was spared that grisly possibility, however, and the
propulsion burn was so accurate that only one of three planned
course-correction maneuvers had to be conducted on the way back - an
adjustment of 4.8 feet per second (1.5 meters per second). After an
uneventful return trip, they splashed down before dawn on December 27 in
the Pacific Ocean, less than three miles (4.8 kilometers) from the
recovery ship.85
As the climax of nearly two years of painful recovery from the tragedy
of AS-204, Apollo 8 was a triumph the American space program badly
needed. It not only restored the prestige of NASA and boosted the morale
of the entire Apollo work force, it provided the confidence in
spacecraft and ground-support systems that no other, less daring,
mission could have provided. About all that remained before the first
landing was to prove that the lunar module could carry out its part of
the mission; two flights in 1969 would test that last important link in
the system.
Besides its operational tasks, Apollo 8 had some photographic
assignments that would give flight planners additional information about
potential landing sites and settle important questions about the use of
landmarks to determine the spacecraft's position. Overlapping vertical
and oblique photographs were taken to determine the elevation and
geographical position of features on the far side, information needed
for accurate determination of the lunar module's position before it
descended for a landing. [see Chapter
6] The crew was also given a list of photographic targets of
opportunity, selected from sites of scientific interest, to supplement
the imagery from Lunar Orbiter IV. Although the
photographic objectives were not completely fulfilled, the pictures
returned by Apollo 8 added considerably to the store of knowledge about
lunar surface features.86
Equally valuable were the crew's visual observations of landmarks and
potential landing sites. Their reports on the sharpness of landmarks,
the ease of locating them, and the topographic details that could be
seen from 60 nautical miles, reduced many of the uncertainties about
what a lunar landing crew might be able to do by eye. Among other
things, Borman's crew determined that lighting constraints (the
allowable sun angle for optimum visibility) were on the conservative
side; they found no difficulty in observing surface details at sun
angles of 2 to 3 degrees, considerably less than the 6 degrees adopted
as a lower limit. They reported that the maps and photographs they
carried, together with last-minute instructions from the ground, were
adequate for locating surface features.87
80. Phillips, "Minutes of the
Apollo Site Selection Board Meeting of March 26, 1968," May 6,
1968.
81. Brooks, Grimwood, and Swenson,
Chariots, pp. 265-72.
82. Ibid., pp. 256-60, 272-74.
83. Ibid.
84. Ibid., pp. 274-84.
85. MSC PA-R-69-1, "Apollo 8
Mission Report," Feb. 1969, p. 3-2.
86. Ibid., pp. 4-1 to 4-9.
87. Ibid., pp. 4-8 to 4-9, 7-19 to 7-20.
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