$Unique_ID{bob00971}
$Pretitle{}
$Title{Apollo Expeditions To The Moon
Chapter 7: 'This Is Mission Control'}
$Subtitle{}
$Author{Kraft, Christopher C., Jr.}
$Affiliation{NASA}
$Subject{apollo
flight
team
operations
spacecraft
landing
mission
moon
control
crew}
$Date{1975}
$Log{}
Title:       Apollo Expeditions To The Moon
Author:      Kraft, Christopher C., Jr.
Affiliation: NASA
Date:        1975

Chapter 7: "This Is Mission Control"

     The last Apollo flight to the Moon has been called "the end of the
beginning." It represented more than just the end of a program to me.  It
brought to a close a phase of my career.  Apollo had become intimately
interwoven in the fabric of the waking hours of my life and often caused the
remaining hours to be fewer than they should have been.  My first involvement
with the program had occurred at Langley Field, Va., 11 years before the
Apollo 17 flight.  During those formative years of the lunar program I was
faced with the challenge of flying Mercury, and of necessity my commitment to
Apollo could not assume the proportions it would in later years.  Only
twenty-three days before my first Apollo meeting at North American Aviation,
we were flying Friendship 7 and John Glenn on the country's first manned
orbital flight.

     In those naive early days I had no idea I would be charged with the
responsibility not only for flight operations but for managing the computer
software programs that would be used for landing two astronauts on the Moon
and returning them to Earth.  Although in 1962 we had decided we were going to
the Moon, we had yet to figure out how we were going to get there and return,
let alone determine the equipment, facilities, and personnel we would need.
Many difficult hours were yet to be spent in conference rooms, visiting
contractor plants and test sites, and waiting at airports.  I had yet to
experience the frightening experience of disarming an angry young man with a
gun on one of many flights to Cape Kennedy.  The future held both periods of
despair and frustration and those exciting and satisfying moments when we flew
that were to make it all seem worthwhile.  Now, with Apollo 17, it was coming
to an end.  I found it difficult to accept the finality of that landing on
December 19, 1972, near the USS Ticonderoga in the Pacific Ocean.  The
challenge would never again be quite the same.  Apollo was like an
intoxicating wine and certainly the last of the vintage.

Vigilance and Judgment

     "The accomplishments of this last Apollo mission and the successes of the
previous Apollo flights were the result of the dedicated efforts and the
sacrifices of thousands of individuals." I have difficulty recollecting how
many times I stood on the platform at Ellington Air Force Base welcoming the
returning flight crews and heard those words repeated.  But they are
nevertheless quite true.  The people in Houston were with their astronauts
each step of the way.  The interchange between Mike Collins, serving as the
CapCom (capsule communicator), and Bill Anders as Apollo 8 orbited the Moon
clearly demonstrated this feeling.  Mike called Apollo 8, saying "Milt says we
are in a period of relaxed vigilance." Bill came back with "Very good.  We
relax; you be vigilant." They came to rely on the controllers, as they well
knew their very lives depended on their vigilance and judgment.  Mike later
put it well in his book, "Carrying the Fire".  He writes of the Gemini 10
reentry and their reliance on "Super Retro" John Llewellyn.  Mike says that
they knew if they made a mistake John would be so angry that he would stick up
his strong Welsh arm and yank them out of the sky.  John's dominant
personality is illustrated by the time he was coming on duty for his shift in
the Control Center and, finding his parking space taken, he simply parked on
the walk next to the door rather than waste time looking.  Like his
compatriots, John was thoroughly dedicated.  His type is at its best when
fighting wars or flying missions.

     Many individuals were involved in the building and testing of the
spacecraft and its systems, but once given the spacecraft and the necessary
facilities and equipment, the Apollo Operations Team was charged with the
awesome responsibility for the accomplishment of the mission.  This team was
composed of hundreds of individuals - government and contractor personnel, as
well as representatives of the Department of Defense and of foreign nations
such as Australia and Spain.  Each team member had been carefully selected and
subjected to countless hours of training and simulations; each had also
participated in Mercury, Gemini, or Apollo testing and flight operations.
Time and time again, these young men had to rely on their technical knowledge
to assess the unexpected and determine the right course of action. The "luck"
the Operations Team had in overcoming adversity is exemplified by the words of
University of Texas football coach Darrell Royal: "Luck is what happens when
preparation meets with opportunity." The luck of the Operations Team was the
result of thorough and careful planning and training and the development of
both people and procedures.

     Thinking back over the events of the past years, I realize the Operations
Team was always prepared when the opportunity presented itself. I'll certainly
always remember their performance on Apollo 11.  It takes an awful lot of
events all going right to get you to the Moon, let alone return. It was our
first attempt at the landing and we had somehow, incredibly, reached the point
where we were starting the descent for the landing.  Thus far, all had gone
astonishingly well.  The first phase of the firing of the lunar module engine
went well as the descent started; and then, approximately five minutes after
ignition, the first of a series of computer alarms was received via telemetry
in the Mission Control Center and was also displayed to the crew onboard the
lunar module Eagle.  I was responsible for the software in that computer, the
logic that made it all work.  You can imagine the thoughts racing through my
mind: Had we come all this way for naught? What was wrong?  The flight
controller responsible for assessing the problem, 27-year-old Steve Bales, was
faced with an immediate decision: Should we continue the descent or initiate
an abort?  An abort meant there would be no landing for Apollo 11: we would
have to try again.  When Flight Director Gene Kranz pressed him for his
answer, young Mr. Bales' response was the loudest
and most emphatic "go" I have ever heard.

     But it wasn't over yet.  The lunar module was under automatic control as
it approached the surface.  Neil realized that the automatic descent would
terminate in a boulder field surrounding a large rim crater.  He took over
control of the spacecraft and steered the Eagle toward a smooth landing site.
The low-level fuel light for the engine came on, indicating about enough fuel
for only 116 seconds of firing time on the engine.  With 45 seconds of fuel
left, Eagle set down with a jolt and we were there.

A Lightning Strike

     I could recall any one of hundreds of incidents that have occurred over
the years as we flew Apollo.  Launch has always been an uneasy time for me,
and I always looked forward to successful separation from the booster.  When
one adds to this an apprehension caused by bad weather over the Cape, I become
even more concerned.  It turned out that all of the elements were present for
Apollo 12.  The launch was made into a threatening gray sky with ominous
cumulus clouds.  Pete Conrad's words 43 seconds after liftoff, electrified
everyone in the Control Center: "We had a whole bunch of buses drop out,"
followed by "Where are we going?" and "I just lost the platform."  The
spacecraft had been struck by lightning.  Warning lights were illuminated, and
the spacecraft guidance system lost its attitude reference.

     The spacecraft was still climbing outbound, accelerating on its way to
orbit.  There was not much time to decide what should be done.  The crew was
given a "go" for staging and separation from the first stage of the Saturn V
launch vehicle.  Within seconds, John Aaron, the SCM electrical and
environmental systems engineer, found what had happened.  Pete was asked to
switch to the secondary data system so that telemetry would show the status of
the electrical system.  The crew was then asked to reset the fuel cells, which
came back on line, and Apollo 12 continued on its way into orbit.  Additional
checks were made of the spacecraft electrical system and a guidance reference
was reestablished.  Apollo 12 went on to the Moon.

     A chapter of this book is devoted to Apollo 13.  As I moved up in the
organization, I reluctantly relinquished the job of flight director.  But
there were many well qualified young men to assume this responsibility.  My
faith in their abilities was confirmed by their actions during this epic
flight.  Following the successful return of the Apollo 13 crew, the
performance of the Operations Team was recognized with the presentation of the
Medal of Freedom by the President of the United States to Sig Sjoberg, my
colleague through all the tribulations of Mercury, Gemini, and Apollo.

     Docking was another major hurdle that had to be overcome if we were to
make it to the Moon.  Normally, it went well but I always breathed easier when
it was behind us.  There had been no major docking problems in the program
until Apollo 14.  After five unsuccessful attempts by Al Shepard and his crew,
we still had not made the initial docking with the lunar module.  Previously
we'd always had a docking probe and drogue available in the Control Center, as
well as experts on the system, but now there were frantic calls for assistance
and the absent docking system had to be hurriedly located to help understand
what might be going on thousands of miles out in space.  Procedures were
worked out and another attempt proved successful.

Reprogramming in Flight

     The next Apollo 14 problem occurred just prior to the final descent for
landing at Fra Mauro.  An abort command was received by the lunar module's
guidance computer.  Had the abort command been initiated, it would have
separated the ascent stage from the descent stage and terminated the landing.
The descent had to be delayed;  and, as Al Shepard and Ed Mitchell orbited the
Moon, the ground valiantly tried to determine the cause of the problem.  It
was isolated to one set of contacts of the abort switch on the instrument
panel.  Recycling the switch or tapping on the instrument panel removed the
signal from the computer.  A computer program was developed and verified
within two hours by the Operations Team and inserted manually into the
computer, allowing the computer to disregard the abort command.  The
unexpected came again within minutes.  As the crew started the descent to the
Moon, the altitude and velocity lights of the computer display indicated that
the landing radar data were not valid.  This information provided essential
updates to the computer.  Flight Controller Dick Thorson made a call to
recycle the landing radar circuit breaker.  The crew complied.  The lights
were extinguished and the necessary computer entry update was made at an
altitude of about 21,000 feet.  Apollo 14 and Al Shepard's and Ed Mitchell's
climb almost to the top of Cone Crater are now history.

     There were occasions when the problems that came up did not require an
instant decision but rather resulted in long hours in conference in Mission
Control.  For example, on Apollo 15, the flight of Endeavour and Falcon, as
the spacecraft traveled from the Earth to the Moon, the service propulsion
system developed a problem.  This is the system that is required to place the
spacecraft in orbit around the Moon and on its trajectory back to Earth.
Needless to say, this was a critical system.  A light had illuminated showing
that the engine was firing while it obviously was off.  This had to be caused
by a short in the ignition circuitry.  Had this circuit been armed while the
short was present, the service propulsion engine would have fired.  The
Operations Team, working with Don Arabian, a legend in his own time, and Gary
Johnson, an excellent young electrical engineer, isolated the short to one of
two systems.  A test firing was initiated by the crew to verify that the short
existed on the ground side of one of two sets of valves.  Procedures were then
developed by the ground, working with the flight crew, and the mission
continued.

Long-Distance Solutions

     Apollo 16 had its unique problems and one was a major one of the
instantaneous and serious variety.  Just after separation of the CSM from the
LM, prior to initiating final descent for the landing, a maneuver was to be
performed by the command and service module Casper to circularize its orbit
around the Moon.  Preparations for the burn went well until a check was made
of the secondary yaw gimbals.  These gimbals controlled the direction of
thrust in yaw plane for the service propulsion system, a system that was
essential to insuring that the astronauts could get out of lunar orbit.  The
gimbals appeared normal until the motor was started and then they exhibited
rapidly diverging oscillations.  The two spacecraft were asked to rendezvous;
and Jim McDivitt, the Apollo Spacecraft Program Manager, met with Bob Gilruth
and me to tell us that it appeared to him that the mission would have to be
terminated.  Another meeting in an hour was scheduled to review the bidding.
By the time we had the second meeting, the Operations Team, through extensive
testing and simulations, determined that the oscillations would have damped
and the secondary servo system was safe to use.  John Young and Charlie Duke
proceeded with the landing, as I reflected on the phenomenal capabilities of a
group of young engineers who had solved a problem of a spacecraft 240,000
miles away from Earth.

     Apollo 17, the final mission to the Moon, clearly demonstrated the
maturity of the Operations Team.  For the first time, a manned launch was made
at night.  A landing was made in the valley of Taurus-Littrow, the most
difficult of any of the Apollo landing sites.  The spacecraft performed in an
outstanding fashion, and there were no major problems.  Minor ones that did
occur were handled without difficulty.

     The problems encountered were all overcome due to the careful pre-mission
preparation, rigorous testing, planning, training, and hours and hours spent
simulating critical phases of the mission with the flight crew.  These
simulations prepared the controllers and the crew to respond to both normal
and abnormal situations.  Their record speaks for itself on the adequacy of
the training.  This was not brought together overnight, and in 1962 we were a
long way from Taurus-Littrow.

     The basic flight-control concepts used for Apollo were developed by a
small group of people on the Mercury Operations Team.  In 1958, under the
leadership of Robert R. Gilruth, the Space Task Group had been given the
fantastic responsibility of placing a man in orbit around the Earth.  Those
few young men who assumed this task did not have any previous experience on
which to rely.  It had never been done before.  What they did have was the
willingness to tackle any job, and a technical capability that they had
attained through an apprenticeship in what I consider to have been the
Nation's finest technical organization, the National Advisory Committee for
Aeronautics.  Other members of the Mercury Operations Team had experience with
aircraft development and flight testing with the Air Force and Navy or with
major aircraft companies, both within this country and in particular with AVRO
of Canada.  That country's cancellation of the CF-105 with its attendant
effect on the AVRO program proved to be a blessing to the United States space
program.  Many fine engineers came to work as members of the Space Task Group
at Langley: Jim Chamberlin, John Hodges, Tecwyn Roberts, Dennis Fielder, and
Rod Rose, to name a few.  The operational concepts that were developed by this
cadre on Mercury were improved as experience was gained on each flight.  As
the Operations Team assumed the responsibility for flying Gemini, the concepts
were further developed, expanded, and improved.  There were many essential
steps that had to be taken to get to the Moon.  For the Operations Team,
Gemini was one.

     Only a small group of people were involved in Mercury operations.  When
the team was given the responsibility for flying Gemini, and with the Mercury
flights continuing, the organization had to be expanded.  A conscious effort
was made to bring young people into the organization.  With an abundance of
recent college graduates, the team took on a young character.  The additions
brought with them the aggressiveness, initiative, and ingenuity that one finds
in the young engineer.  They did not all come from major colleges; there were
graduates of Southwestern State College in Oklahoma, Willamette University in
Oregon, San Diego State College, Texas Wesleyan College, and Northeastern
University in Boston, to name a few.  A large contingent of officers was also
made available by the U.S. Air Force and this group provided excellent
support.  I came to rely on these young people and I can honestly say they
never let me down.

An Advanced Computer Complex

     As the team was being built, the facilities and equipment were also being
defined, developed, constructed, and brought on line.  The Mercury flights
were directed from a control center at Cape Canaveral, Fla.  In 1962, the
Space Task Group moved to Houston to form the Manned Spacecraft Center. The
construction of the Mission Control Center in Houston, designed to accomplish
the lunar missions, was started in 1962.  Thirty-six months later it was to be
used to control Jim McDivitt's and Ed White's flight in the Gemini IV
spacecraft.  Its full capability was not used for Gemini, however, as much
work still had to be accomplished.  One of the most advanced computer
complexes in the world had to be integrated with a global tracking network.
Tracking and telemetry data had to be relayed from stations in Australia,
Spain, the Canary Islands, Guam, Ascension Island, California, Bermuda,
Hawaii, Tananarive, and Corpus Christi.  Tracking ships were built to provide
additional communication coverage in ocean areas.  Special Apollo Range and
Instrumentation Aircraft (modified Boeing KC-135 jets) were deployed around
the world.

     All this was being done concurrently with the evolution of operational
concepts.  During the Mercury and Gemini flight programs, teams of flight
controllers at the remote tracking stations were responsible for certain
operational duties somewhat independent of the main Control Center.  The
advantages of having one centralized operations team became more apparent, and
for Apollo, two high-speed 2.4-kilobit-per-second data lines connected each
remote site to the Mission Control Center in Houston.  This permitted the
centralization of the flight control team in Houston.  Provisions were also
made to tie into the Control Center, through a communications network, the
best engineering talent available at contractor and government facilities.

     As engineers from the Goddard Space Flight Center were intently
determining the requirements for this ground communications network, building
and installing equipment, and laboriously testing and verifying the network's
capabilities, engineers in Houston, led by a young Air Force officer, Pete
Clements, and a fine young engineer, Lynwood Dunseith, were feverishly working
to integrate the computer complex and Control Center displays with the
network.  The critical parameters and limits that had to be monitored in
flight needed to be defined; the necessary sensors for measuring the
parameters needed to be incorporated in the design of the spacecraft; and
rules for utilizing the measurements needed to be developed.  But it was not
only a question of ensuring that the right measurements were made.  Spacecraft
and subsystem design also had to have the redundancy and the flexibility
needed to overcome failures and contingencies as they arose.  And time was
relentlessly marching on.  Testing of the spacecraft revealed new problems,
and new techniques and procedures often had to be developed to avoid potential
difficulties in flight.  Programs had to be developed for operating the
spacecraft and Control Center computers, and the programs had to be verified,
tested, and incorporated in the computers.  The end of the decade moved closer
each day.  The complexity of the spacecraft and launch vehicle was exceeded
only by the complexity of a worldwide ground-control system.

     Then came January 27, 1967, and the AS-204 fire, a day I'll never forget.
I was at the console in Houston monitoring the test at the Cape, together with
a group of flight controllers.  We thought we had considered every
eventuality, and now we were struck down by an event that did not occur in
space but happened during a ground test.  There were no excuses that could be
offered but, out of the despair of the fire, there came a rededication to the
successful accomplishment of the goal and an intensified effort on the part of
every individual.

     The Operations Team had many functions not associated with testing and
checking out the spacecraft and controlling the mission.  These functions were
nevertheless essential to success.  One was recovery operations.  Recovery
techniques for the spacecraft and the crew had to be worked out in conjunction
with the Department of Defense and the U.S. Navy.  Bob Thompson organized and
led this effort during Mercury and Gemini.  The organizational team he
established provided the same excellent recovery support for Apollo as it had
for Mercury and Gemini.

Maneuver Targeting

     The team also developed the techniques for flying the spacecraft and
controlling its trajectory.  It had the primary responsibility for developing
the programs or logic used in the computers onboard the lunar module and the
command and service module as well as those in the Control Center.  Except for
rendezvous maneuvers, the Control Center was the only source of maneuver
targeting; that is, determining the exact magnitude, direction, and the time
for executing each flight maneuver.  Bill Tindall, a truly outstanding
engineer, contributed significantly to this effort.  Operations were planned
in detail before a flight.  Plans were based both on everything working
properly and on the "what if" situations that might occur.  The "what if"
situations could not be carried to the point of actually reducing reliability
by introducing confusion or complexity into the system.  This was quite often
a fine line to walk.  Techniques also had to be developed for monitoring all
essential systems during critical mission phases.  The procedures, the
techniques, the personnel, and an organization all had to be defined and
developed, a task of no small magnitude.  Each landing demonstrated how well
the task was performed.  Apollo 12 was a classic example, with an incredible
pinpoint landing some 600 feet from the Surveyor spacecraft that had
previously landed on the Ocean of Storms.

     To conduct operations for the flights, four complete flight-control teams
were organized and used for all Apollo missions.  Each team was headed by a
flight director; Gene Kranz, Cliff Charlesworth, Glynn Lunney, Gerry Griffin,
Pete Frank, Milt Windler, Neil Hutchinson, Phil Shaffer, and Chuck Lewis were
all assigned this responsibility during various phases of the program.  To
simplify the overall training program, each team was assigned different events
or activities.  The individuals on each team could thus devote their full
attention and energy to developing proficiency in accomplishing a few things,
as opposed to having to cover an impossible spectrum.

     The team was responsible for developing the mission plans to demonstrate
the capability of the spacecraft, the systems, and the team to land a crew on
the Moon.  A series of unmanned developmental flights was planned with well
defined objectives to be demonstrated on each flight.  Apollo 7, the first
manned flight, occurred in October 1968, and the first flight to the Moon,
Apollo 8, occurred two months later.  Even while Apollo 7 was flying, the
Operations Team was performing simulations and training for the Apollo 8
mission.  As Apollo 8 was flying, training and simulations were being
conducted for Apollo 9, the first Earth-orbital flight of the LM and CSM in
March 1969.  The next step, Apollo 10 - a dress rehearsal for the first
landing - was taken in May 1969.  On this flight, on the far side of the Moon,
a fuel cell was lost and taken off line.  The team had trained for this
contingency and reacted accordingly.

Training Crews and Controllers

     Astronaut training and development of the flight plans and crew
procedures were directed by Deke Slayton.  He accomplished these tasks in an
outstanding manner.  The training that Deke provided the crews, as well as the
training provided the flight controllers, gave them the capability to react to
the unexpected.  Quite often it resulted in unique training devices and
equipment.  The zero-gravity environment was simulated by using a modified
KC-135 aircraft that flew parabolas, thus creating 20 to 30 seconds of
weightlessness.  A neutral buoyancy water tank was also used to simulate the
weightless environment.  The unique Lunar Landing Training Vehicle (LLTV) was
developed to train the astronauts in controlling the lunar module during the
final phase of its descent and landing.  The test flights of the LLTV, for
example, saw the successful emergency ejection of three pilots - Joe Algranti
and Stu Present, research pilots, and Neil Armstrong, the commander of the
first lunar landing mission - because of vehicle failures.  Bob Gilruth and I
both believed that flying this craft was more hazardous than flying the actual
lunar module.

     Simulators also had to be developed to provide training for the flight
crew in the operation of the spacecraft.  These simulators were tied in with
the Mission Control Center so that an integrated training could be
accomplished with the flight controllers.  These simulations allowed the
flight crew to train realistically for all phases of the mission, including
the landing itself.  Unique display techniques were used with actual models of
each landing site.  The models allowed the crew to gain familiarity with the
terrain and recognizable landmarks.  Detailed lunar maps that were based
primarily on data provided by the NASA unmanned lunar orbit program were
prepared by the Air Force Information and Charting Service and by the U.S.
Geological Survey.

     As the system matured after Apollo 11, greater emphasis was placed on
scientific training and on ensuring that the astronauts were prepared to
perform scientific experiments when they arrived on the Moon.  Prominent
scientists both from within the government and from universities throughout
the country offered their time and talent to ensure that the crew and the
Operations Team were adequately trained to perform the demanding scientific
tasks.  During the mission, they also participated as members of the
Operations Team.  Apollo brought a new aspect to spaceflight as man on the
surface of the Moon worked in conjunction with a science team on Earth that
capitalized on his observations, judgments, and abilities.  They assessed his
comments and evaluations, and modified the science planning and objectives in
real time.  This was not accomplished, however, without moments of frustration
and anguish during the early flights, when the acceptability of the spacecraft
and its systems was yet to be proved.  During the later lunar missions, the
crew and the Operations Team were working with proven procedures and a proven
spacecraft, and the capabilities of the science organization were effectively
integrated in the performance of the missions.

     As a means of saying thanks, on March 5, 1973, this group of scientists
held a dinner for a number of the program and operations personnel they had
worked with over the years.  The events of that night clearly showed how well
this relationship had developed.  As late as 1969, there were very few that
would have been brave enough to predict such a dinner would have ever
occurred.

Contributions of Flight Surgeons

     Chuck Berry and Dick Johnston and their medical personnel also played an
important role as members of the Operations Team.  Working with engineering
personnel, they developed the monitoring techniques used to observe the
critical medical parameters of man in flight.  The flight surgeons' judgment
and ability to assess the astronauts' well-being in flight as well as their
confidence in the crew's readiness to undertake each of the missions were very
necessary to achieving success.  In the beginning, there were some who doubted
man's capability to even exist, let alone work, in the environment of space.
Chuck Berry had no such doubts and worked hard to alleviate such concerns.  I
do not believe that we could have gotten to the Moon without the contributions
of the flight surgeons.

     The Apollo Operations Team was a unique group brought together to
accomplish landing on the Moon and return to Earth.  I do not believe that the
dedication and the capabilities of these people have ever previously been
duplicated, and I doubt that such a group will ever be brought together again.
A great amount of preparation preceded the actual flying of an Apollo mission.
The spacecraft had to be designed, built, and tested, but the group that
actually flew the mission was faced with an awesome responsibility. President
Truman had a sign on his desk in the White House stating that "The buck stops
here." This comment could well be applied to the Apollo Operations Team.  For
these young men and women, the Apollo missions were their finest hour - the
truly great adventure of their lives as well as of mine.