NASA Johnson Space Center
Oral History Project
Edited Oral History Transcript
Interviewed by Carol Butler
Houston, Texas – 26 April 2001
Today is April 26th, 2001. This oral history with Ed Pavelka is being
conducted for the Johnson Space Center Oral History Project, in the
office of the Signal Corporation in Houston, Texas. Carol Butler is
the interviewer, and is assisted by Kevin Rusnak and Tim Farrell.
Thank you very much for joining us this morning.
It's my pleasure.
To begin with, if you could just tell us about how you became interested
in aviation aerospace, what kind of guided your career and led you
As a very young boy, my father always encouraged me to get into engineering.
At that point in my life I had no idea what engineering was, but I
always remembered that he encouraged me to do that. He was a very
mechanically inclined person, so he, my father, was my main encourager
to go in that direction. As it turned out, when I got older, my interests
in math and through high school and into college, math and science
So when I graduated from high school, I looked for a college that
I could go to where I could study aerospace engineering. It was called
aeronautical engineering when I began, but as I went through school,
the curriculum changed and they added courses and it became aerospace
engineering. So my father was really my main supporter and inspiration.
It's good to have that family support.
How did you then learn about the opportunity at NASA? Did you move
right into that after college?
It was my first job straight out of college, and I guess, you know,
President [John F.] Kennedy had inspired the country, and that was
sort of like a star that was shining. I was not smart enough to know
at the time that that's exactly what I wanted to do, but it was like
a dream. When I came to time for graduation from college, it really
was a seller's market at that time. I received like thirteen job offers,
and the very last one I got, very late, was from NASA, and it was
very lowest paying. I didn't hesitate, I accepted it, because, for
one, I'm a native Houstonian. I sort of liked to come back to the
Houston area. But number two, I was, of course, interested in NASA.
Again, it was like a dream that I wanted to fulfill. So it all worked
Certainly seems to have.
It was wonderful, and it was such a right time, too. I could not have
known it at the time, but it was a very glorious time to get into
the space business. It was my first job, so I had nothing to compare
it with, and I would go to work every day and do things that people
would say, "Wow! What are you doing out there?" And I just
thought that's what everybody did. I didn't know any better.
That certainly seems to—It's a similar story to what we've heard
before, even though it was a low offer and didn't know the extent
of how challenging it was, or was going to get over time. What was
then your first job that you moved into when you came to them?
I came in early 1964. Glynn [S.] Lunney was my first supervisor, and
my first assignment was in the flight dynamics. I was a flight dynamics
officer. They called us FIDOs. That was a fairly small group of people
when I first joined the organization. There were only three or four
people that were doing that type work. Glynn Lunney, Cliff [Clifford
E.] Charlesworth were doing Gemini work at that time. We had another
couple of people that were beginning to work more in the systems area,
the telemetry part.
But our area was trajectory, where we would learn how to determine
the trajectory of a spacecraft from launch on into orbit. There were
orbiting satellites, and so there was a little bit known about Earth
orbit at that time, but the technology for the radars and how you
could put various radar data together to make a good solid trajectory
was still being developed. So that was a challenge for us to make
sure we knew where the vehicle was, because our job was to create
the maneuvers that would do whatever you needed to do, whether that
was raise the orbit, lower the orbit, get it ready for landing, provide
a maneuver that would land you at a certain point.
Of course, in Gemini we landed in the water with a parachute, so there
was a boat out there that wanted you to be close to them. Most of
the time we did pretty good. But my first job then was in the trajectory
How did you learn all of these techniques, the procedures, how to
plot these trajectories? What was the process that you went through?
It was very much what you'd call on-the-job training. Our mentors,
I guess, were Lunney and Charlesworth. They were the guys that had
been doing it, and Chris [Christopher C.] Kraft [Jr.] before them
a little bit, and then Carl [R.] Huss was in the trajectory area,
also from the retrofire standpoint. He was a retrofire officer.
It was that you studied books. The first book that I studied was one
on the Mercury launch trajectory data system. You had to learn about
how the data flowed so that you knew how to tell the people to switch
trajectory sources, because we had the traffic sites for the launch
all the way out to Bermuda. We knew things about—some of them
got noisy under these conditions. We had to know that.
So we also would get memos that would come through the office. In
those days, there wasn't so much paperwork as there is today. You
could fill many rooms like this with paper. In those days, there was
precious little paper. The people that got it were the guys like Cliff
Charlesworth and Glynn Lunney. So it was our job to watch for when
new paper came in and we would try to get a copy of it.
Ken [Kenneth W.] Russell, a friend of mine, that had just entered
the workplace before me, he and I shared this one book that we had
on the trajectory data system, and we would find memos and stuff and
get to work early in the morning, copy the memo, because nobody thought
of, "Let's make copies of this and give it to all the people
so they'll know what's going on." You had to look out for yourself.
It wasn't that they were keeping it from you, although to us it kind
of seemed that way, but it was that they were so busy carving new
ways to go.
So Russell and I, and then several years later, Steve [Stephen G.]
Bales joined us. We were the first wave of new-hire people out of
college that had joined the space program. I guess I was really the
first new hire, or fresh out, from University of Texas that joined
Lunney's organization. We studied and studied, and then we began in
the, like for the Gemini II mission, that was pretty well set up and
planned before I joined NASA. Although it had not occurred yet. So
I was able to watch the Gemini II mission from the Mercury Control
Center at the Cape [Canaveral, Florida].
But then for Gemini III and IV, we were bringing the new control center
along here in Houston, so I was on the blue team with John [D.] Hodge,
and so we simulated and simulated and simulated, and the group of
people who put the training on, and we call it simulations, their
job was to make it look as lifelike as possible. And it really did,
although in the beginning we didn't know it was going to be looking
lifelike, because we didn't know what a real one looked like. But
they did an excellent job. So a few pieces of paper, a lot of training
and simulations, and a lot of conversations with folks like Lunney,
Charlesworth and Kraft.
Then, of course, in those days before we opened up the control center
here, everyone would gather together, pack their bag, go off to the
control center at the Cape, and you sort of lived together down there
in a motel. You'd get together in the evening and you'd swap ideas
and stories and they would debrief problems. Then you'd all go out
to eat. And so a lot of it rubbed off on you by osmosis, that here
were the guys that knew what you were supposed to do.
For the Gemini III we were at the Cape, and Lunney and Charlesworth
and [John S.] Llewellyn [Jr.] and Charlie [Charles B.] Parker were
running the consoles and they were going to be the main controllers.
I was a trainee, you know, and so then they said, "Ed, get over
on the console." I'd watched them for a few simulations, but
I had never sat at the console. "Ed, get over to the console
and you take the next run." Well, this terrified me, because
Kraft was the flight director, and of course, in those days I really
felt like he walked on water. In fact, I still kind of feel that way
about him. One of my favorite people.
But we had the simulation, and it was a fairly gentle one, if you
can imagine that. They didn't really throw the book at us. But in
those days our data was all controlled from Goddard Space Flight Center,
so like tracking data would come in from Bermuda, but it would go
to Greenbelt, Maryland, and then it would ship down to the Cape. So
we had all these delays, but you needed to know how to talk to these
people and tell them, "Let's switch over to this data source
if this one is getting noisy."
There was that, plus there was monitoring the trajectory. We had the
big plot boards where we had the nominal line, and, of course, the
vehicle was supposed to follow the nominal line. If it didn't, you
needed to know what to do. So the seat I sat in was one of very few
in the control center that had an abort switch. If you flipped that
abort switch, it lit a little light in the spacecraft and it told
the astronauts to abort the mission, to fire the rockets, whatever
they had to do in that particular stage of the mission. So there was
a lot of responsibility and it was a lot of pressure for me, but they
didn't tell me that they were going to do this, so I had sweaty palms.
I can certainly understand why you would. I take it the simulation
went okay then.
It was okay. It wasn't perfect, but I guess it was their way of just
throwing me in the water. After it was over, I felt a lot of better
and I felt a little more confident. So I guess that's probably as
good a way. It was a little fun for them, I'm sure, to see me squirm,
as I didn't know what was going to go on.
As you mentioned, it was a lot of on-the-job training, and that's
one example of that. How many simulations would you go through approximately
before the mission came up?
Typically, I think we would have maybe two to three months of sims
where you had them pretty much every other day at least. A day of
sims, if it were an on-orbit sim, there might only be two or three
runs. If they were launch sims, you might have fifteen runs in one
day. So it was pretty tiring.
We did have a backup person in those days, so we would have the prime
person and we'd trade off. Maybe not every other run, but some of
the runs the backup person would get, because it didn't happen very
often, but periodically you would have a person that would be ill,
or the classic problem on the freeway where they would be in an accident
or whatever, and you would need to have a backup. So we, the flight
crews had that in those days, and we had backups in the control center.
Not 100 percent, but it's the best we could do it.
What then was the first mission that you worked completely on console
instead of watching?
It would have been the Gemini IV mission. That was where we had the
blue team, and we actually trained here in parallel with the prime
team that trained at the Mercury Control Center at Cape Canaveral.
We, under John Hodge, we had just one ship and we trained with as
many simulations as they did and, of course, we had a unique control
center. We were getting the benefit of learning how all the new digital
TV displays worked, how all the controls worked. We had new positions
down in the—we called it the RTCC. It was the real-time computing
Today, the controllers do things with a keyboard. In those days we
had a position that we would call like computer supervisor or computer
dynamic, and we would ask them to input certain parameters to computer
maneuver, or configure the computers for launch or whatever. So we
were learning all that protocol here.
Then for Gemini III, we paralleled what they were doing, but it was
not really a full-up backup of the control center here. For Gemini
IV, it was really our first time when we were on line. If they had
asked, we could have switched over and controlled the flight from
here. It turns out that the control center at the Cape had a power
problem during that flight. I didn't know, and I think most of the
people in our control center here did not know that they were experiencing
Of course, Kraft had his prime team at the Cape, and I think it would
have been a pretty cold day before he was going to turn his control
over to this other control center. I don't know what was going through
his mind, but our data and our information on telemetry for the systems
was all perfectly good here. From my position, we didn't really know
there was a problem at the Cape until after they debriefed the flight.
They were fairly miffed that we had good data and they didn't. Of
course, they were in real hot seat, but just like this, they could
have said, "Houston, you're in control." That didn't happen.
But we would have had a good mission had they done it. The mission
turned out just fine as it was, but they were very fortunate. There
were no anomalies during the period when they had their power problem.
That certainly shows the value of having that backup there when needed.
It was. Of course, NASA, from the very beginning, have always been
very conscious of having backup systems and plans to control every
anomaly that might happen, every failure that they could think up.
You have to take your hat off to the simulation people for really
doing a good job on keeping our feet to the flames on training for
When it did come time for the missions, as you're participating in
the actual ones now, you've gone through the simulations and the training,
what then would your duties be as a FIDO? What were you watching for?
What would you, obviously working on trajectory, if you could tell
us a little bit about how that would go during a mission.
Let me start before the mission and say that we had a big part in
the maneuver planning. We worked with a group called Mission Planning
and Analysis, whose charter was to formally document all the plans
for the flight. But in the process of doing that, we had to have a
very strong operational input into the plans for launch, the plans
for the on-orbit maneuvers, the plans for the de-orbit and entry.
We called it retrofire in those days. And the placement of the ships,
and there was a lot of strategy that was operational that was our
job in mission control.
So we worked to put together the plans that we would follow and then
those were what we rehearsed in the simulations. So then when it came
time for the flight, my main responsibility was that whole envelope
of trajectory-related items that have to do with from the launch of
the vehicle through the powered flight into orbit. That's one very
large segment there. I'm going to put that aside for just a minute,
though. Then the on-orbit would be when you would separate from the
boosters and the spacecraft would be in free flight for on-orbit.
There your job was to determine with the tracking data how accurately
did the booster place the vehicle in orbit, the spacecraft. What is
your tracking data telling you? What is the next planned maneuver
that is going to occur? Our area, the trench, let me introduce that
part of it. The trench was the front row of consoles in the control
center and the FIDO was sort of the team lead for the trench. The
FIDO was responsible for computing maneuvers, establishing a tracking
data, and he was sort of in control of the real-time computing complex,
but with him were the guidance officer and the retrofire officer.
In those days they called him the retrofire controller, but John Llewellyn
decided that he should really be called an officer, and it became
the retrofire officer. But in the beginning it was the guidance officer,
the flight dynamics officer, and the retrofire controller. John, if
you ever see this.
Anyway, so the guidance officer would be in charge of the inertial
guidance system on board the spacecraft. There was also a radio guidance
system on the ground that controlled the booster from a place called
GE Burroughs [Corporation], and they had a radio guidance system that
basically gave all the controls from the ground to the Titan booster.
So the guidance officer had that control and then also he was responsible
for updating all the parameters in the on-board computer.
My job was then to compute the maneuvers that would, for example,
if you had an off-nominal orbital parameter where the booster didn't
put you—maybe you had an underspeed, where it should be in—in
those days we wanted an 87 nautical-mile perigee by 161 apogee. That
was the orbit that we inserted into. If you had an underspeed, your
high point might be 140 miles instead of 160 miles. So if you didn't
correct that, when it came time to land, you were going to be in the
wrong place in the orbit to retrofire. So we tried to optimize the
shape of the orbit for when you would go ahead to the point where
you needed to retrofire, because in those days we didn't have very
much propellant on board.
So if you had your maneuver at the wrong point in the orbit, it could
be that you would have not quite enough propellant to do what you
needed to do, or you'd have to revise the attitudes to the point where
it was an optimum reentry. So that was our job. It all wrapped up.
Then the retrofire officer, who was also under FIDOs task force in
the trench, he was responsible for mass properties. That's the weight,
the CG [center of gravity], the consumables, and, of course, he worked
with the systems operators to find out how much water you had, how
much propellant you had, how much oxygen you had. We knew where all
those were located, so he computed where the center of gravity was,
because when it came time to fire the engines, you need to know where
the center of gravity is or you get in an incorrect response from
the engine. The autopilot doesn't know where to point the engine.
So our job together were to keep the vehicle, know where it is, know
where it's supposed to go, compute the maneuvers that take it where
it's supposed to go, and then track it after you did the maneuver
to see if the maneuver was correct. So it was an iterative process
that never ended, and you always had a bad batch of radar data coming
in that you had to determine that was a bad batch of data and there
wasn't something different happening to the spacecraft. Because when
you first see it, you believe this is real data, but in some cases
those radar stations would have biases or a different problem.
So the team, including the controllers, we had a person that was called
Track, who would work with us for the tracking data down in the computer
complex, and he would analyze this tracking data and make recommendations
to the FIDO of what he thought, how it fit the other data, because
our job was to know is there anything that's happened on board? Are
we venting? Have we had an unusual attitude control maneuver that
may have had a propulsive component? Because that would change the
orbit. The tracking data would pick that up. If the tracking data
said something happened, but we knew nothing had happened, then we
had to edit that data out. So that was another part of our job.
Then when you did the maneuver, the retrofire maneuver to land, all
you had after that point—see, this vehicle had an off-center
center of gravity, the Gemini did, so depending on the attitude that
you roll to the lift vector, didn't have much lift because it was
just, you know how the vehicle—wish I'd have brought my model.
I have a model. But we could roll the lift vector around to control
whether the vehicle would go to the left of the ground track or the
right of the ground track.
That was mainly the retro controller's job to do that, but the FIDO
and the retro worked together, because he's wanting to know how good
is our tracking data and he's wanting to know from the systems people,
are we venting or is our attitude control system working properly.
He's wanting to know from the guidance officer, is the on-board computer
working properly, does your data look correct. We had comparisons
that we were making about how the onboard computer worked.
So it all sort of fit together in the trench there, and that's why
we called it a trench, because we really stuck together and we depended
on each other as a unit to stick together.
Certainly teamwork is a huge part of all of this.
That's a great overview of how all of that works together. Thank you.
You had mentioned the launch portion that you were going to come back
to that. Was there anything further you wanted to say on that?
In the launch, it's a set of trajectory mechanics all its own, but
the part that I dwell on mostly is the on-orbit part, and that's the
orbital mechanics, Kepler's laws of motion, and we had little rules
of thumb about how maneuvers would affect the trajectory and how much
propellant it would take. We knew all this in our head, and we had
little notes on the console. But the launch, the launch was the place
where people could get killed, where you had to call aborts, where
things were happening so quickly that you had to have enough simulations
that you knew exactly what you had to do if you had a certain problem.
So every FIDO, when he was prime for a mission, he would have the
launch phase and then certain other on-orbit shifts, because we had
three teams in those days, eight-hour shifts plus the overlap. But
the prime FIDO for that mission was responsible for the overall pre-mission
planning. He also did the launch, the powered flight part.
Remind me a little later on, I think that this will come up when I
talk about memorable things, but there was a first apogee rendezvous
that we did on Pete [Charles] Conrad's [Jr.] flight that was very
much involved with how the launch phase monitoring and that we pretty
much had to have an absolutely perfect flight with the booster to
be able to accomplish.
But for the launch, it was an animal all unto itself. The data was
high-speed data. Your displays would update every half second. You
had telemetry data coming in, in addition to the radar data. So the
FIDO was looking at two or three sources of radar data and telemetry
data all at the same time, trying to decide which ones are the most
accurate, best represent what's going on, because the FIDO has the
potential of making this abort call that I mentioned.
So at all times what you're protecting is, I have to keep the very
best trajectory here in the control center for everyone to use, but
most especially for the FIDO and the flight director, who either one
of them could send the abort light if there were a trajectory deviation.
Now, other people in the control center could ask for an abort if,
for example, their system were beginning to have a severe problem,
they would call that directly to the flight director.
The FIDO, because of the time-critical environment that he was in,
looking at data every half second changing, watching trends on the
big plot boards and the telemetry, sometimes what we would do is if
the trajectory would begin to deviate, and you know it's going to
be a problem, but we had limit lines on our plot boards that we helped
develop, those limit lines would protect things like the G forces
that the astronauts would have to go through if they performed an
abort. In those days we used like sixteen Gs. That's a lot of pull.
That's about as much as they could handle without having a severe
For example, if the trajectory were deviating and went into this sixteen
and a half G line, then the FIDO would send the abort light, which
was sort of a bat handle-looking thing that you had to pull up. I
mean, it had all kinds of safety precautions. But ours were really
the main time-critical ones in the control center.
We had mission rules that we went by. Let me just touch on that. That
was a big part of our pre-flight planning. Basically we thought through,
if this happens, this is what we will do. So in this case, if the
trajectory deviated and went to the sixteen and a half G abort line,
the FIDO will send the abort light. That's the condition and the ruling.
So the FIDO and all the team, the flight directors, go through many,
many hours of reviews of these mission rules. Then we exercised them
in a simulation.
So then on flight day, here you're sitting in the hot seat, you know
your mission rules up here. You've got your abort light, you've got
your data coming in. So if on a real launch day the trajectory deviated
there, we would call the abort.
In the Gemini Program, they would have done an abort where they fired
the retro rocket. The retro rockets were on the bottom of the heat
shield, which was up against the booster. For this abort mode they
would fire the retro rockets, they called in salvo, meaning all together.
That would lift and then the explosive bolts would fire, the whole
spacecraft would come off the booster…. So we would have these
different abort modes depending on what flight regime you were in.
Let's see. I'm not sure I want to get ahead of myself here, but there
were a lot of new things that we were coming up with. For example,
for certain types of launch deviations, if you cut off with a low
velocity, the right answer could be, "Don't make a maneuver right
now. Coast around a half an orbit up to apogee, and apply some energy
there." That was a brand-new technique that, I guess, Lunney,
Charlesworth, and I came up with, and I plotted out using a lot of
parametric data, plotted out where we would have this line on our
plot board. So that if your trajectory deviated around and hit this
line for cutoff, it meant "We do not have a correct orbit, but
don't try to fix it right now. Wait for it."
Now, this was tough for people to think about. Your orbit is not going
to make it around, but hold tight and just wait until you coast up
to apogee, which is the high point. At that point if you apply your
maneuver, that's the most efficient place to raise this low perigee.
So if we were looking for 87-mile perigee by 161-mile apogee, and
if we had an underspeed, and our vehicle perhaps would intersect with
a flight path angle, if it were a positive flight path angle, we could
coast, because we were headed toward the high point. If it were a
negative flight path angle, it means we're going down, we need to
do something now. We need to change our attitude and fire the thrusters.
But if you're coasting up, you just rest easy, coast around to your
apogee point and apply some maneuver.
We had to come up with the processors and the computers that would
compute what would that maneuver be, and we had to know it real quick,
because most of the time we had to voice that up to the astronauts
before they left voice contact at the last down-range station. We
couldn't wait until just before they—we don't have satellites
like we have today for complete coverage. We had ground stations.
So you were tied to this little tracking area, this little tracking
area, where we also had voice.
So you hurried and you got your maneuver computer and you voiced it
up to the crew, and then the crew wrote that down on what we called
a pad message. Then at the right time they fired the thrusters. We
gave them the attitude to go to, how long to fire the thrusters, and
we even gave them backup things like, if your computer has failed,
because this was a very serious, if you didn't perform this maneuver
you were going to die. So we gave them even backup ways that you could
look through the sextant on board, look at a certain star, that will
put you in the right attitude and burn the thrusters.
So we had all kinds of what you might call back-of-the-envelope ways
to give them backups, because in those days we had the computer and
then we had the out-the-window, where they could look either for stars,
or we had a line scribed on the window for the backup for reentry.
It was a 31.7-degree angle where they would turn. If they didn't have
any computer at all, they could look at the horizon and roll the vehicle
until that line was on the horizon and they were in the right attitude
to reenter, so that they wouldn't burn up.
So that's some of the stuff that we kind of did in the planning stages
before the flight occurred. Probably more than you want to hear about.
Oh, no, not at all. It shows the complexities of all of it, everything
that has to be taken into account, and it all did work so well.
Throughout the whole program. Mentioning that it was a different thought
process for people, as to maybe it's not time to react right away,
maybe wait until you come up for the apogee, ties into the whole orbital
mechanics idea with rendezvous. As you were building in, obviously,
the Gemini missions, that was a key point to be able to make Apollo
possible. At first some of that wasn't as well understood when they
started with it. I think it was on Gemini IV, Jim McDivitt tried to
do a rendezvous with the booster, but wasn't able to, because some
of the processes hadn't been entirely—
That was a situation where the instincts of the pilot were to drive
straight at the target, we'll call it, the booster. It turns out that
Kepler's laws say that if I apply energy at this part of the orbit,
it's going to raise the orbit over here. If he were firing in a horizontal
mode, what he would begin to do, he should stay in the same orbit
with the booster, if he wants to rendezvous with it. But to move over
there to it, what we didn't know in those days was, a radial maneuver
rather than a horizontal maneuver thrusting at the target would be
the way to go, because that would bring you back right to the target
one orbit later. Again, you have to be patient.
In those days, a lot of the astronauts were test pilots, silk-scarf
guys, we called them. They were excellent stick and rudder men. In
this case, I think what happened was that the pilot instincts took
over and he would thrust toward the vehicle. Well, initially, he would
move that way, but then orbital mechanics would take over and he would
begin to realize that velocity that he'd put in with his thrusters,
180 degrees around there, it's raising his orbit. So he's getting
over there and he's going away from the target, rather than to it,
because the Kepler laws of orbital mechanics are taking effect. So
then he would thrust some more, just made it worse.
So after a while they called it off because of the use of the propellant.
Those types of rendezvous were studied, because when you're very close
to something, the strategy for a rendezvous, it's almost proximity
operations and it's a little different strategy than if I launch and
my target vehicle is 1,200 miles in front of me and I have three days
to plan maneuvers between now and then to get there, which was the
classical way that we planned rendezvous.
We sort of invented the book on the rendezvous in the Gemini Program,
and as you said, it was to make sure that we had that capability for
the Apollo lunar program, because it was absolutely mandatory that
we know how to rendezvous in a routine and predictable and comfortable
way, repeatable way, because the lives depended on it. That was their
way to get back.
So for Gemini we start out with very simple sets of maneuvers where
we would have maybe sixteen orbits, sixteen orbits times an hour and
a half would be how long you would have for this rendezvous. In the
course of that, we would plan maneuvers that would adjust height,
if we needed to change the phasing. What our computers would do is
our computers would propagate out sixteen orbits, tell us where we
were going to be, and then we would know how to make small corrections
in either the height or phasing maneuver to correct phasing.
Then at some point we would have phasing maneuvers, height adjust
maneuvers, and then finally we would have, for the later rendezvous,
we had what we called a co-elliptic maneuver, where we would go at
some constant distance, maybe ten miles below. So that would give
us a very slow catch-up to the target, that would give us a good opportunity
to track both the target vehicle and our maneuvering vehicle, make
other small corrections, so that we would have a perfect condition
when we did what we call terminal phase initiation, TPI, is what we
called that maneuver. That maneuver would be the last maneuver that
you do before you would intercept the target.
So we had, I guess, the first real structured rendezvous like that
was supposed to be the Gemini VI, and because we had problems with
the target vehicle it became the Gemini 76. That was unique. It was
supposed to be our first real taste of rendezvous, and yet in our
computing complex down in the first floor of the control center, it
was looking for an Agena to be the target vehicle. The Agena was a
big stage that had big rocket engines on it, and certain kinds of
thrusters and certain kinds of mass properties. We had certain formats
of the tables that we used to control that.
Now, what we have in there is a second Gemini is the target, and it
has different thrusters, it has different characteristics, different
weight, etc. So one of our challenges was very quickly to come up
with a way that we could package the Gemini characteristics in a target
vehicle slot in our computing complex to where we could treat it just
as we treated the Agena target vehicle and it would be passive. But
to do that, we really had to go in and modify some of the code in
the computers to accommodate a different characteristic, a different
set of characteristics for the target vehicle.
So that was a little bit of a surprise, but again, we had worked with
the people building the code and, of course, they were the programmers.
We weren't programmers, but what we knew was in English language we
knew what needed to be done and we knew the capabilities in the English
language, not in the ones and zero's code. So we would get with the
programmers and the people that were the computer controllers and
figure out how we would modify the codes. Some of us went over to
the IBM [International Business Machines] Building and worked with
them to talk about how the changes would be made, what kind of testing
we needed to have.
In those days, it's really almost funny, but we had IBM 7094s, which
would do 1 million instruction per second. Your home computers do
hundreds and thousands of times faster than that today. It's incredible.
But in those days, that was pretty spiffy, and of course there were
no home computers in those days.
So the first rendezvous. Then we built on everything. Once we had
that mission behind us, we debriefed, we talked about what was our
next step. We wanted to become more and more—our operational
capabilities, we wanted to be more failure-tolerant so that if we
had anomalies at any point in the flight, the rendezvous technique
would be forgiving and it could accommodate those things. Later I'll
talk about this similar thing in Apollo.
So then we went through the series of Gemini missions, each of the
rendezvous missions building on the other. I need to refer to my notes
here for just a second and make sure I have this right. Let's see.
It was Gemini XI. Gemini XI, we wanted to try something very aggressive
and new, and so it was Pete Conrad and Dick [Richard F.] Gordon's
[Jr.] flight, and we were going to try a first apogee rendezvous.
What first apogee is, is here you are on the Earth, and you launch
here at the Cape, right around here, forty-five minutes later is your
first apogee. So normally we had been waiting sixteen orbits to rendezvous.
We were going to do this in forty-five minutes.
What it meant was that you had to have an absolutely perfect launch.
So we defined a little tolerance box at insertion that was equivalent
to a half second of launch window. So you had to have absolutely on-time
ignition, a perfect vehicle trajectory, and all the systems are working,
and the radars and everything else is working.
Steve Bales and I worked with Pete Conrad and Dick Gordon a great
deal on our techniques, because we had a lot of backup things that
we used, little charts that we had where they could do things manually
if they had certain failures on board. They had a special simulator,
a hybrid simulator, in St. Louis, that we went there with this Bales
and I and Conrad and Gordon went there and spent a day in the simulator
going through these backup techniques.
So to get to the bottom line, when it came time to fly Gemini XI and
we really had rehearsed this, but we knew it was very success-oriented,
I guess you'd say. We knew everything had to be exactly right. On
launch day, everything went absolutely perfectly and we had our first
That didn't catch on as something that we decided we wanted to do.
After looking at how precise everything had to be, we decided that
that was not in keeping enough with things that could happen in the
real world and it was a little too ambitious. We knew we had that
now in our bag of tools. If we needed it, we knew how to do it. But
as far as embracing that as a way that we wanted to do business, it
was better to get into orbit, let your vehicle be checked out, look
at all your systems in zero gravity, make sure that they're working
properly, how is the crew doing, start doing the maneuvers in a methodical
build-up way. We decided that would be the best way to go. So that's
a little bit about how we evolved to where we got for the rendezvous
techniques for Apollo.
We pretty much took the code that we had for the basic maneuver techniques
out of Gemini, moved those into Apollo, changed them for what we needed
to change because of the booster and the spacecraft differences. But
as far as Kepler was concerned with the orbital maneuvers, we didn't
really change a lot.
Certainly just took and built on all of those experiences.
It was very much a building-block-type approach and it worked well
You mentioned the first apogee rendezvous and then you mentioned that
most of the times before that you had done the multiple orbits before
you would rendezvous. Were there any other different types that you
would test that fell in between those?
Yes, we did. I'm not sure I can recall each of them, but we had a
couple that were intermediate that would be like a fourth orbit. Then
we decided that the sixteen orbit was really the best as far as being
able, within the propellant that we had, to be able to take out the
types of dispersions that—in other words, let me go back a little
bit. When we got a booster delivered from the Martin Company, they
would say there is a certain dispersion envelope that we expect for
this vehicle. If you take those dispersions and the uncertainties
of how well the Gemini spacecraft can hold attitude and how well those
thrusters can perform exact velocity maneuvers, if you take all those
uncertainties into account, it's smart planning to be able to have
something that will handle that times ten, if you can, every time.
So we looked at the different rendezvous for contingencies. If we
had a reason why we needed to be in a certain place, maybe battery
power was running out or something like this, and you had to have
an earlier rendezvous, we looked at them for those type reasons. But
for our work horse, so to speak, the ones that were like sixteen orbits
seemed to be the most forgiving and handle the most dispersions.
You've mentioned a couple of the missions now. I believe on Gemini
XII—and you had mentioned some of the backups that the astronauts
had in case something went wrong with the computers, because they
did have to do these things at that certain time. On Gemini XII, I
believe they had a difficulty where they did have to put the sextant
into play at one point, and with Buzz [Edwin E.] Aldrin [Jr.] and
he had even a lot of background in rendezvous. Can you mention a little
bit about that?
Well, Buzz was probably the strongest person we ever had on theory.
He had done many studies on it. A lot of the astronauts had learned
everything they knew after they came on board here. Buzz sort of brought
him a lot of background and theoretical, so it was very natural for
him, in light of a computer failure and problems where he had to go
to the backups, he understood just second nature, he understood the
theory of how the inertial positions, shooting stars with the sextant,
and how this would work as a backup method for computing maneuvers
For that particular rendezvous I was not on the consoles. I'm giving
you my recollections of what I learned and what I was told. But he
had absolutely no problem in using the backup techniques and the sextant.
We had a number of pre-thought backup techniques that had like curves
that were drawn that would say if you have this reading, then this
is the attitude that the vehicle should go to. We had a number of
charts like that, that the crew would carry with them in addition
to Earth map things that they could roll around that had the ground
tracks on them that would move manually. So that they really had a
lot of independent ways that they could calculate things. But they
needed information from the ground as best they could get it on where
was the target vehicle and where they were.
Now, if their computer was not working and we had to give them that
information in more of a time and space pointing thing, or look at
these stars, do this type of alignment. That's about as far as I can
go on that.
Sure. Were there any other incidents on any other of the mission,
or not even incidents, or any memorable moments on any of the other
missions on Gemini that you'd like to mention?
There was a high profile of public interest and media interest in
all the Gemini flights, and after each shift, I mean, almost for the
whole program you were on console and it didn't matter if you were
on console from 6 a.m. to 2 p.m., or 10 p.m. to early in the morning,
after the shift was over, the flight director, and he would select
one of the controllers for an interview, and they would go over to
the media building. The press were over there and they would debrief
that shift. There was a very high profile of interest there.
Probably the most memorable moment I can think of in the Gemini Program
was when the control center was online and we had proven that everything
that we had really worked several years for was coming together. Then
we saw anomalies in simulations and then anomalies in flights happened,
and we were able to handle it with the control center that we had,
with the people, the procedures. That just was a very fulfilling time.
I'll repeat that back in those days we didn't realize that we were
doing anything very unusual at all, because our world was—we
were immersed in this group of people and that's what we all did.
I didn't know that the other people in other walks of life weren't
doing similar things. It just didn't occur to you. You were so busy
that you paid attention to trying to do the very best job that you
could do, and in those days you didn't really worry much about a career
path. I never heard the word "career path" until I was a
supervisor fifteen years later.
What you did is, you did your very best and you trusted that your
supervisor would take care of you. I was fortunate to have some of
the best supervisors. We'll probably get to this later, but in 1968
I was only there four years, I became a supervisor, so I not only
stayed on the console for the remainder of the Gemini flights, but
we had a group of people that were beginning to break off and look
at the Apollo profiles. There was a whole series in the beginning
of those that were unmanned that I had from '68 to about '70. We not
only had the flight dynamics officers in that section, but we added
in the retrofire officers.
So it was really then called the trajectory section, and then in addition
to that we had the guidance section. So those three made up the trench.
So we took what had been three sections and made it to two. So I had
the FIDOs and the retros, and for, I guess, a couple of years there
I tried to learn as much as I could about what the retros did, but
my main hands-on part was still as a FIDO. We'll talk later about
the fact that I had to step in one of the later Apollo missions, because
we had a medical emergency with one of the retro officers, and I had
to take on that hat. But I don't want to jump quite there just yet.
What I would say is, taking on the job as a supervisor, I loved working
with people. I loved the job. There was not quite so much administration
in those days. It was more of a technical leadership job, and not
so much a time cards and budgets and any of this type of stuff. The
main strategy was, we had missions now finishing up the Gemini Program
beginning the unmanned flights of the Apollo Program and they were
beginning to overlap.
One of my jobs as supervisor was to figure out how to staff the lead
person and the other two shifts on these two programs that were overlapping.
That got to be fairly hectic, and, of course, the guys always wanted
to—by this time we were beginning to get quite a few more people
in the group, too, because we were beginning to staff up for Apollo.
So the people always wanted to have the more important or aggressive
assignments. Not very many of them were content to have the sleep
shift unless there was another important shift [for them] on that
mission. Although if they were the top guy on this [other] flight,
they didn't mind being the sleep shift on this flight, because you
didn't have to do very many simulations for that and you were really
simulating a lot as a lead controller.
So there was a balancing act with that number of people, and, of course,
it was highly technical because the Apollo guys were off learning
a whole new set of vehicles and systems and trajectories that went
with Saturn and the Apollo vehicle, and we were trying to finish out
the last three flights of the Gemini Program. So we were flying a
flight a month there for a while, and it was like the Dunkin' Donut
man, you met yourself going out the door in the morning, almost.
I had a young family, and so we didn't get to spend as much quality
time with our families when they were young as we'd like to, because
we were simulating just to keep up with what was happening next on
the closeout of the Gemini Program and the buildup for the Apollo.
Certainly the families had their own sacrifices that they did make
They were great. Looking back on it, you kind of realize that there's
some stuff you missed that you just can't quite go back and get that,
but you can catch up with your grandkids. [Laughter]
You certainly can. You certainly can. We have found that the grandkids
like to hear these stories. That's one of the benefits of the oral
Moving into Apollo then, as we've come to the end of Gemini and you're
moving into this supervisory role and trying to figure out how to
reach this balance between the both, how much were you still primarily
focused on the Gemini missions yourself, or did you also begin that
Apollo training and working on some of those unmanned missions?
The very beginning of the unmanned Apollo missions I was pretty much
depending on the lead people that I assigned to participate in the
mission planning and the trajectory design. What I had gotten involved
in heavily was how we were changing our computing complex to handle
the new maneuvers. We had a lot of reviews on changes that we made
in the computing complex.
But we had some very talented people in our area. They were young
people, but they were highly gifted people, and we handed them lead
responsibilities. Of course, we had backup people behind them. And
we kept a close eye on how the simulations were going.
But I was involved in like this flight-a-month business and my primary
technical focus remained on the closeout of the Gemini Program. My
branch chief understood what was going on, what he had done to me,
so to speak, and was very helpful in helping the oversight of the
early planning for the Apollo unmanned. Now, there were only two or
three of those got very far before we closed out the Gemini, because
that part of it was only three months long.
I'll just mention a couple of the people. We had Phil [Philip C.]
Shaffer, [H.] David Reed, Bill [William M.] Stoval, Jay [H.] Greene.
These folks were all in the section and they were very talented, capable
people. They picked up some of the planning for these early Apollos
and did a fine job. Some of them tended to want to be so complex at
what they did, that they frustrated the people in the mission planning
area. Remember that, again, our role from operations was to add the
operations flavor and the operations perspective to the planning,
but our charter was not primarily planning.
However, I'll give credit here, I guess, to Dave Reed. He did a lot
of the planning for one that we called Apollo Saturn 258, and it had
a rendezvous where you went away and then they called it a double
bubble, it came back like this. I'm motioning with my hands, but you're
trailing and then the vehicle goes down in altitude and then begins
to catch up, and then finally there's a rendezvous. Dave made this
planning so complex that we actually had some letters of protest from
some of the people in the mission planning community, because he was
driving them to their knees.
So what we had to do was balance this energy and this talent that
we had and channel it into the right direction, because we had some
folks that would like to their part and the part that the mission
planning people did, roll it all together. "We'll do it all."
And they probably could have. But in order to keep peace in the valley,
we had to keep our people within their charter.
So let me just go ahead and move into early Apollo. The first Apollo
mission that I worked on was actually one of early manned Apollo missions.
I was not the lead on that, because we had had several of my lead
people that had been planning those while I was finishing up the Gemini
Program. But it was a very steep learning curve because those people
had been off line for several months learning the new systems, the
new computers. The computer system was totally different. There were
more computers and they operated differently, much more capabilities.
Of course, remember this was all really designed for the goal way
out there was to do the lunar rendezvous. So to do an Earth orbit
mission with this, you didn't quite use all the capabilities that
these onboard computers had. But what we wanted to do was test those
out. So we tried to influence missions that would exercise each one
of the features that were in the onboard computers, the propulsive
systems, all the onboard systems, as well as the crew capability to
do backups in the event of failures. We wanted to exercise all that
in these early manned missions, so that when we stepped off out of
Earth orbit we had a lot of confidence that our kit of tools was complete
and we knew how the tools worked and they worked okay.
In this time period, my focus very quickly became the translunar mid-course.
In other words, when you apply the translunar injection maneuver to
go out of Earth orbit, you're on a coast period for 240,000 miles,
and there's a change into the Moon's gravitational field out there.
There is a lot of time, but the sensitivities were that you needed
to be within, in the very beginning, like 60 nautical miles of the
lunar surface when you went around the closest point.
So I began to dwell on how the processors that would compute these
maneuvers for mid-course correction, how would those work for the
translunar coast and then back for the transearth coast. This problem
included the fact that we knew precious little about all of the different
harmonics of the Moon's gravitational field, that it was not a smooth
basketball, but it was lumpy and there were these mascons [mass concentrations],
these concentrations where the gravity would actually change an orbit.
We had been fortunate enough to have some early lunar orbiter data.
We imported a young man from Jet Propulsion Lab named [W.R.] Wollenhaupt,
and he was pretty much the free world's expert on lunar gravitational
potential. He actually came to work for the Mission Planning and Analysis
area, but we had to integrate his knowledge into this mid-course package
and also the lunar orbit package that we had in our computers in the
control center, because this was beginning to be fairly theoretical.
We'd never done this before. We knew what you could do in Earth orbit
and how vehicles behaved. We knew a lot about the solar system, but
we didn't know exactly how well our 85-foot radars that we brought
online—we brought like three of the big deep space 85-foot dishes
on from Gulfstone and Canberra and other places, how accurately would
these work, how well could the data be brought into the control center.
So I spent probably most of my free evenings for about a three-month
period over to IBM Building along with people like [James L.] Leroy
Hall and Bob [Robert] Regelbrugge and others, testing these mid-course
sequences that we had over and over and over again, because we had
several different types of mid-course strategies that we could use
between here and the Moon. Some of them were called free return. Free
return was a nice warm feeling, because if you executed it properly,
you did your translunar injection and during the coast you did this
free return mid-course correction, and if nothing else happened, you
would swing around the Moon and come right back home and be set up
for entry. Of course, never quite would work exactly that way, but
that was the goal of that sequence.
Then we had another one called best adaptive path, that would actually
minimize the fuel used, because we only had so much fuel available
to go out to the Moon and then to come back. So the whole strategy
of what types of mid-courses that we would use, how well the logic
worked, was all the theoretical information folded in there correctly,
we simulated and simulated and we used lunar orbiter data. Our friends
in Mission Planning, we got to be one big happy family there, because
we had to understand that we had exactly the right package in there.
The translunar injection was important, too, but that was targeted
by the Saturn booster. It had onboard logic, and we paralleled that
logic in our computers here in the control center. But they had some
logic called hyper surface targeting, and that was all put together
by our friends at Marshall Space Flight Center and [Wernher] von Braun's
team of people.
The Saturn was probably one of the most magnificent boosters that
you could ever imagine. I still marvel at what they did with that.
I mean, that was such a fantastic piece of hardware. Of course, I'm
mainly a trajectory guy, so I will refer to the guys that dealt with
the systems as "those systems weenies," you know. They just
So the Saturn targeting for the translunar injection, there were opportunities
to correct whatever happened at the end of that with this mid-courses,
and that's exactly what we were trying to do was be able to take a
deviation from that TLI maneuver, make whatever mid-course corrections
on the way to the Moon, so that you got just in there with the right,
we called it pericynthian, the closest approach.
Then we had another new process called the LOI, the lunar orbit insertion.
That was a brand-new processor, and what it had to know was, it had
to know all about orbital mechanics around the Moon, because its job
was to take this trajectory that was speeding in from the Earth, slow
it down to the point where you were now just orbiting around the Moon.
It had to put you in an orbit that was a safe orbit. So it had to
know all these lunar harmonics over the gravitational field around
the Moon. It had to know all the Keplerian things, plus all the maneuvering
characteristics of the Apollo.
So more testing, wee-hours-type testing on the LOI maneuver. I guess
we progressed along with our testing in parallel with these Earth
orbit, low-Earth orbit maneuver missions. Then we had a high apogee,
Apollo 8, where we boosted the orbit way out just to do a big test
of the S-IVB engine, but not so far as to get out of the Earth's gravitational
Then I guess we decided that we might go around the Moon and might
do that early. So a team of us, they didn't want to talk about it
much until they were sure that it could happen. So Jerry [C.] Bostick,
who was my branch chief at the time—and again at this point
I'm still the section head in the trajectory section—Jerry and
I began to plan toward what would it take to go around the Moon and
into lunar orbit, rather than just do a high apogee or whatever. We
worked for several months on that, and probably the other people were
busy enough that I'm not sure that they thought about what was going
on. Because we were planning later flights that would go to the Moon
also, so you could always cloud your questions in a way that it could
apply to a later mission.
But the whole thing had to be opened up to three full teams of people
in time so that we could do the right training, because you don't
want to just say, "Surprise!" Then the people are sitting
there not knowing whether they're confident. When you're on the console,
you have to have confidence that you know what your tools will do,
you know what you can do. You know that you've trained every way that
you possibly can. If you don't have that confidence, it's a terrible
feeling sitting on the console.
So we introduced that idea. We had three great teams of people. It
was a wonderful flight. We got to exercise our mid-course strategies
and our processors. It all worked great. The tracking data confirmed
that we—and see, that's rather independent. When you fire that
mid-course correction, you think you know where you're sending the
vehicle, but when the radar tracks the vehicle and comes back and
says, yes, that's really where it's going, then your confidence builds.
So on the way to the Moon, we began to feel better about our deep
space tracking, about our mid-course calculations.
So then comes the time of going into lunar orbit. Well, the only way
you can test that is to do it. I was on console, but we had practiced
that and we had a fine processor to calculate the maneuvers, and we
had a lot of confidence. But the truth of it is, we had never really
done it. So we're all there and it's feeling a lot like a simulation
and we compute the maneuver and everything looks very similar to what
things have looked in the past. So the maneuvers get voiced up and
the crew writes it down, they read it back, everything is just fine.
But then the vehicle ducks behind the Moon, you have loss of signal,
and time passes. And it was not until that time that we all realized
how well we did this maneuver. The test of that is we're calculating
what time the vehicle comes back around and you get radar and telemetry
back, and voice. We should know whether, if we hear them early, that
means something. If we hear them late, it means something else. For
example, if we hear them late, it means they have a little more energy,
they're higher. If we hear them early, that's not good, it means they're
going faster. It means they're lower. You go faster as your orbit
So we all begun to get exactly the tenths of a second of when we were
going to have acquisition. There were some sweaty palms and everyone
was nervously going to the restroom and checking their sack lunch,
whatever you would do. But deep down inside, we were all just praying
that this was going to happen just like a storybook, and as it turns
out, we were lucky and it did. They got some great pictures popping
around the Moon.
[Frank] Borman was a great guy to work with. He was not a pushy—he
was a very unassuming regular kind of a guy. We had a lot of respect,
the whole team had a lot of respect for him, because he would come
sit down with us in meetings where we had our control team there,
and roll his sleeves up and work with us. I mean, it didn't matter
whether he was going to have a space suit on later or not, it didn't
So that was a great experience there and it was very memorable. It
was probably some of the whitest knuckles I've ever had. When you
think about all the training that we had and the confidence that we
tried to build up and all these things that were new, that was the
one, I guess because it was a fast happening and it was a hazardous
thing. The mid-courses you had time you could do that, you could track,
you could watch, see how it went, you could correct. The LOI maneuver
was not forgiving. You had to do that right, and so there was a lot
Certainly for the first time ever doing that.
When they came back around the Moon and radioed back and it was on
that exact moment that you had calculated so precisely, the feeling
must have been pretty neat.
It was a feeling of relief and we were tickled and we were proud,
and some of the guys had little flags and they were waving them. It
was just really like you'd climbed a mountain and you were finally
at the top. That was sort of a climax point for us and we were thrilled
Many people have indicated that Apollo 8 was almost a bigger moment
for them than Apollo 11, because it was achieving so much for the
first time and it was actually getting to the Moon for the first time,
and had so many unknowns to it. Whereas, Apollo, by the time of Apollo
11 there was only one unknown left, was the landing. Do you have any
thoughts on comparing the two?
I think I would agree that, at least for me, the excitement was more
because it was the culmination of so many new things. Frankly, at
that point in time, we weren't thinking ahead of how important landing
on the Moon and bringing rocks back would be. We were enlarging the
envelope where we worked. We were getting it a little larger and a
little larger. So I would say, for me, the excitement was much more.
The landing on the Moon, the big unknown there was, of course, the
performance of the lunar module [LM] in that environment, and again,
our knowledge of how the trajectory would give you the pinpoint landing
Again, where I sat, the actual opening of the door and stepping down
on the Moon was almost passé because what I was about was getting
there. We were in the middle of every orbit of the command module
around the Moon, while they were on the Moon, we were busy computing
"what if" emergency launch times for every time they could
lift off, because if something happened to one of the suits or the
oxygen supply in the LM, or the propellant in the LM, or a dozen other
things, we had to be prepared to get out of there right away.
On [Apollo] 8, we were essentially in a safe mode when we were in
lunar orbit. Once you were there, it was a balanced situation and
you were just moving along waiting to come back to Earth. But getting
into lunar orbit was probably the very high point.
Moving—is it okay to move to [Apollo] 11 and talk about that?
Actually, if we can take a quick break and we'll change the tape and
then we'll go right on to [Apollo] 11.
Okay. [Tape change]
Let me begin with a little bit of background comment from the standpoint
of the supervisory role again at this point. About this time, the
assignment of people, particularly the lead operators, is beginning
to be more of a challenge. We had two people that were highly qualified
to be the lead operator that would be on console for the landing of
Apollo 11. We had Dave Reed and we had Jay Greene for FIDOs.
Because Dave Reed had been the lead operator on the previous mission
and doing a fine job, but it was totally gobbling up his time, I assigned
Jay Greene to be on console for the landing. At the time it was just
another shift that had to be pulled. I wasn't thinking of it as this
Well, Dave Reed was incensed. He could not stand it. He was going
to be on console for the first landing, and he went to my boss. We
ended up sitting down, and I went through the rationale, and he just
was not going to have the time to spend in the preparation because
of his other assignments that he was totally involved in.
And another ground rule that we had from Chris Kraft was he wanted
his very best and most experienced operators on console for Apollo
11, because we had folks, some of the folks that we were using them
in other capacities, they were a little more experienced, but we were
using that experience in some of the planning. Brought those people
back in. So we ended up putting our most experienced team of FIDOs,
retros, guidance officers, other people in the control center, on
As it turns out, this one that I just mentioned in particular was
Jay Greene and he would be on console. I assigned myself to come on
console the shift right after landing. So it would be Jay Greene.
At the time, I was not making anything more of it than the technical
balancing of the work, but I heard a lot of complaints over the years
from Dave on that, and I think it ended up frustrating him to the
point where a few years after that he quit NASA and went to work in
Boston for the Department of Transportation. A very gifted person.
Bill Stoval was another one of the gifted young men that was on console
with us. We had a fine team of people.
To get on to the mission now, 11 was pretty much played out just the
way the rest of them did as far as the planning and the performance
of the vehicles and the ability of the people and the tools that they
had. What was new again was the lunar module, and, of course, all
of us in our training, we had to do a landing with a lunar module
as part of our training. So we knew some about the controls, the handling,
the systems, because even though our area was trajectory and guidance,
we needed to know what the other capabilities were, what the systems
limitations were so that when things started happening, we could understand
when the systems people would say, "This system is degrading."
So when it was time for the landing, we had pretty much like a simulation,
and my team came in early for the landing, because we were going to
be on the shift that was—for the landing had been on a long,
very long shift, and the landing was sort of at the end of their shift.
So we were kind of doing our handover in the console there and they
said, "Hey, the crew is opening up the vehicle early and they're
going to start the EVA early."
Of course, again, for me, I was so immersed in what I was doing, it
went right over my head. We'd just keep working and, of course, the
big screens are showing the TV that's showing him stepping off, and
his famous words and that. Again, at the time what I was remembering
is, that my family was at home and they had all the neighbors over
watching it on TV, and I was kind of wishing I'd be there with them
watching it on TV. That was a thought for the moment, because, again,
most of what we were doing, we had trained so much, that it became
routine feeling as far as this happened, now this happens, that went
the way it was supposed to.
So if I were a systems person, I would be very excited about how my
lunar module had just done this first landing. But my part of it was,
it's a machine that was supposed to do this type of trajectory and
we fed it this information and that worked out fine and it landed
where it was supposed to. So I guess I felt like that the important
thing of getting on the Moon was that we gather the rocks and set
the flag and those kind of things. That was a very proud moment when
they set the flag and that. So 11 was very memorable. There was a
lot of excitement.
Then one of the really, really rewarding times was when the lunar
module lifted off the Moon and we then gave them the maneuvers to
do the rendezvous, which we had been working so many years for. Of
course, the lunar rendezvous was successful.
The crew—you never know how tired the crew is, how well they're
feeling, or how badly they're feeling, or if they're an upset stomach.
You don't know these things when you're in the heat of the battle,
because the aeromed flight surgeons made it a practice of not sharing
that information. Occasionally, if they needed to for some particular
reason, they would share with members of the control center. Most
of the time it was the flight surgeon and the Capcom and the flight
director who would know if there were problems.
So we're going by how is the vehicle performing. If the vehicle is
performing, the crew must be doing okay. We're hearing what they're
saying on air-to-ground, but if they're sick, unless they key the
mike the way John Young did one time, we don't know how they're doing.
So it was an excellent feeling in the trench there when we had the
rendezvous after the first lunar liftoff. Then we began to prepare
for "Let's do our transearth injection," TEI. That was the
retro job. He did the bring-them-home maneuvers. So he was busily
making sure—you see, when they bring anything back, we not only
have to know how many consumables they used, but we also have to know
if they brought 147 pounds of rocks or whatever, where they're stowed,
because we're going to do a maneuver that accounts for those things
and where the center of gravity is for the vehicle, because this transearth
maneuver is a very important maneuver. If you have enough dispersion
in that maneuver, you can end up calling for more fuel to correct
it than what you have on board, and that's a bad day. So you want
the very best trajectory that you can have, the very best knowledge
of the mass properties, the very best knowledge of the orbital conditions.
On top of that, we have to know back on Earth is there a storm in
the Pacific Ocean where our ship is going to land, because we have
to target for a landing point here that we corrected all the way back
and we can change. But if, for example, you're going to land in the
Indian Ocean, and there's a big storm there and you really need to
change to the Pacific Ocean, much better if you target that and fold
that into the transearth injection maneuver and then all your corrections
are just very small corrections to remove any dispersions, rather
than "Let's change the ocean that we're going to."
So those are the things that you're thinking about, and we had thought
about those earlier coming back from the Moon, too. But again, this
time we had other uncertainties and new things that were involved,
because we were bringing additional cargo back and we needed to know
where that was and we needed to know any anomalies on the systems
for the command module.
Earlier you had mentioned that you were highly involved with the mission
planning beforehand for a lot of these reasons, figuring out everything
along the way. Moving into Apollo 12, they wanted to get that pinpoint
landing down. Apollo 11 hadn't landed quite, it was in the area planned,
but not the exact spot, and that was important for the later missions.
Did you have much involvement in helping with that planning for that
Only from the standpoint of that that fell in my overall area of responsibility
from the section standpoint. The detailed planning of that would have
been with a retrofire officer. The thing that was unique there was
we carried that as, they called it a DTO, or detailed test objective,
for that mission, meaning you could have done exactly what you wanted
to do or what you did on Apollo 11 for 12, but they wanted to see,
if it were possible, how well could we do this within the tracking
accuracies and the dispersions of the maneuvers and so on. Believe
or not, sunspot activity even affects the atmosphere which can affect
that, so were had our folks working on was there any unusual solar
I might also mention that for all the translunar activity, the solar
activity was really monitored carefully. That was not monitored exactly
in our area, but it was peripheral to our area because it affected
the Earth's atmosphere, which could affect the landing. But as far
as the pinpoint landing, the main thing I would say about that is,
the program decided they wanted to use that as an objective to determine
how accurately we could land this particular hardware. There wasn't
anything unique about [Apollo] 12 that demanded pinpoint, as far as
the content of the mission. It happened to be a program objective
that was set. So, luckily our folks were able to carry out and we
ended up not having any systems failures or anything unusual, so it
It was success-oriented. Sort of like our first apogee rendezvous
was success-oriented. It sort of helps you bound the envelope of where
you can operate, how well can you do these things.
As you were working through the Apollo missions, working with the
team, and you've mentioned several of the different individuals that
you've worked with along the way, and at some point Captain REFSMMAT
came along. This might be an interesting time to work him in. How
did that all come about?
Captain REFSMMAT. Actually, we were coming up in late Apollo and—wait.
I take that back. No. It was in early Apollo. Gene Kranz thought in
the military way about the morale of his troops, so to speak, and
he wanted a way that he could kind of raise the morale. So he talked
to me about something that we might be able to do that would be a
way to get the esprit de corps, get the people really up and help
the team spirit.
So I came up with a number of sketches and we ended up with Captain
REFSMMAT. REFSMMAT stands for Reference Stable Member Matrix. It's
a technical term that had to do with the computers on board, and it
is the way that the computer knows if the body axis of the vehicle
is pointed this way and the gyros, and this way the reference mat
gives you the conversion so that you know where are you pointing in
space. It gives you to the inertial attitude. So REFSMMAT just happened
to be a term. We said, "Well, we'll come him Captain REFSMMAT."
This is out of Gene's book, Failure Is Not An Option. We actually
had six of them in all, and this photo here is not a very good photo,
but it shows beginning where my finger is over here, the very first
one and there's a progression of them, the last one is actually not
Captain REFSMMAT. On your far right, the last one is actually Captain
REFSMMAT's arch enemy, Victor Vector.
The whole idea behind all of these was that it gave the controllers
a way to blow off a little steam, or when something was happening.
Back then, and a lot of people remember this, but the Fugitive, the
original Fugitive movie with the one-armed man and all that, well,
the very first Captain REFSMMAT has quotes, like, "He knew the
one-armed man did it." It had all kinds of little things that
were in at the time. Twiggy, the skinny model, was in. There was comments
about Twiggy on there.
So it was a way, in a humorous way, for people to put stuff down.
Other people would come by and visit at lunch and they would look
and write their little thing down. So it was a way to have a little
bit of fun, let people blow off a little steam. Sometimes if someone
would get upset about something, there would be a little comment on
there about that. But that was a fun part of the thing.
Gene captured that in his book here, along with a lot other neat things
that he captured. Kranz was one of my supervisors for probably all
but about four years of my thirty-three-year career, and he's a fine
guy to work for. He was not the easiest guy to work for, but he was
a great guy to work for, one of the greatest leaders that I ever knew.
I think people like Kraft and Lunney, Kranz are the ones that I really
knew that inspired you to say, you know, "I would follow this
man anywhere, whatever he said."
So that was kind of where Captain REFSMMAT—and that spanned
a period of maybe over five or six years, maybe longer. We just left
them up until people wrote so much on there that they wouldn't last
any longer, and I would sketch up a new one just on a desk pad and
put it up out in the hallway on a side of like a supply locker, and
people would go by and write their stuff on it.
That shows the camaraderie in the control center.
It would help the team spirit, because there was always a little competition
between the trench and the systems guys, and the flight director.
Everyone has their own little group that they're closest to. The flight
rules and the simulations sort of brought people together.
One of the guys that was a bachelor, they complained because of the
travel budget. So he wrote on the Captain REFSMMAT that he offered
to—people would write things as if Captain REFSMMAT said them.
Like, say, "He offered to walk to the Cape, so as to not strain
the travel budget." They were sarcastic things, but the more
sarcastic, the better the guys liked it.
It certainly was a unique environment.
It was different. And there weren't any ladies in our environment
back then. I think it was early—well, let's see. I'm not sure
of the exact year, but I remember the first lady that was in our control
center was named Poppy Northcut [phonetic]. She was back in one of
our staff support rooms. Probably, I mean, everyone had a pretty important
job that worked in the control center, but in the grand scheme of
things, you know, it was an average support room job. But since it
was so unique that it was the first lady flight controller, there
was a lot of notoriety and pictures in the paper and pictures with
the mayor of Houston. You know John. You've met John Llewellyn.
John was a little miffed when he saw the pictures of Poppy in the
paper. He didn't see anything real special that she did. But, of course,
she was breaking new ground in the control center.
Now, when I retired, we had, I don't know if it was 50 percent, but
I mean, there were lady engineers and other tasks in the whole organization.
It was not unique at all. But there was a high period of evolution
in the work force there. I don't know if that was just in our environment
or whether that was everywhere, but it was extremely unusual to have
anyone other than a secretary as a female worker for probably the
first ten or twelve years that I worked for NASA.
You certainly saw many changes like that from the composition of the
work force to the computers, as you had mentioned earlier. Those changed
immensely from when you first came in with Gemini until by the time
you retired in the nineties.
If you could reflect a little bit on those changes and the differences.
Probably in the early nineties our directorate decided that they would
begin to use computers with engineers at their desk. We had a number
of people that were sort of trekkies, you know, that had their own
computers or knew about them, or people that their business was computer
programming. Well, I was none of that, so what they did was they made
us do our daily time charges on the computer. So they forced us, kicking
and screaming, to begin to use computers. So they brought them in
and set them on the desk. So it began with, well, you begrudgingly
put your time sheet in, and then little by little you find out that,
well, you could type a memo here on this, and you could make a graph
Of course, in our area we loved graphs. The trajectory area we thrived.
If we didn't understand something, we would plot it to see if it would
tell us something. So little by little, we began to get more and more
involved with computers, and within a couple of years, most of the
engineers were doing their own composing of their activity reports,
as well as the routine stuff on the computers, and they were beginning
to want more and more capability.
Well, NASA was not exactly on the leading edge of what was out there.
We were always one or two generations behind private industry in terms
of how powerful the computers were or what spiffy computer programs
you had to do things with. That got better past the sensitivity of
how that could be useful was better appreciated by management. But
in the beginning I think a lot of the management sort of felt the
way I did, they put up with it, but they didn't really embrace it.
About the time Windows '95 came out, I was really beginning to embrace
the computers and, of course, by that time—I'm stepping ahead
a little bit here—but I was then a division chief. Let me just
mention an intermediate step there, because from the trajectory section
that I had, I was selected as a branch chief in the Flight Planning
Branch. The Flight Planning Branch had been led by Tommy W. Holloway.
Tommy was going away to become a flight director for the first time,
so I took his branch over, the Flight Planning Branch, and this was
before the first Shuttle. We were about a year away, year or year
and a half away from the first Shuttle launch when I took over that
branch. So we had all of the launch and landing. Maybe I shouldn't
jump to Shuttle yet. Is there something else you want to talk about
Actually, we're getting close to eleven o'clock. I think before we
do move on, I'll ask Kevin and Tim if they have any questions on what
we've covered so far, if that's all right. Kevin?
Yes, I had a couple. One of the things you've been talking about is
the use of computers and how they've changed and the importance of
that to the job you had to do. Do you think the trajectory planning
and all this, and even the operations, would have been possible through
the Apollo period or Gemini without the use of computers?
Absolutely not. There's no way. The thing that we were doing, the
processing, for example, of the trajectory data, it would use hundreds
of thousands of individual data points and it had smoothing routines
and you'd finally come out with a vector, and the maneuver calculations
that we did, even for Gemini, for the rendezvous, there's no way that
you could have done all that manually. We were able to do a little
work manually on rendezvous, but we could have never determined the
orbits manually. So computers were an absolute necessary tool.
The evolution of computers in the control center, we were pushing
the state of the art on that, because we needed bigger, faster, just
whatever they had. In those days, IBM sort of had a monopoly on what
was in the control center and so we were always just, you know, what
are they going to have next? They came out with the 360s, we thought
that was the greatest thing in the world. But, yes, that was a crucial
On a lighter note, you've been alluding to some of the other people
in the trench. You've mentioned a couple of descriptions here and
there of some people like John Llewellyn or whoever. The trench is
certainly known for its colorful characters. We've heard about you
guys from many different flight controllers and flight directors we've
talked to. So I wondered if maybe there were any more personal stories
you'd care to share about yourself or some of your colleagues, from
kind of the heyday of Apollo or whatever, that you think might shed
on light on their character, some ones that, I guess, are clean enough
to tell on camera.
Well, this is a little difficult, because we were surrounded by characters
in the trench. Let me just mention a couple. Of course, John Llewellyn,
Marine-type guy, you know. I'll just make one short story about him.
John was a retro. John was several years my senior. He had come from
the Langley, Virginia group, and he had that little West Virginia
twang in his talk, so people loved to hear him talk. He was a fairly
foul-mouthed guy, and I'll just leave that part at that. But he was
very colorful. John had a little farm, he had cattle and he liked
little horses and stuff like that. He had a little sports car, a little
Triumph sports car, that he drove from Alvin up, and we'd have simulations
of the flight.
One evening he was running very late for his shift. Someone may have
already told you this story. But he came zooming into the site on
JSC, and he went into the parking lot. He was coming on console. Didn't
see any parking places, so he just pulled up on the grass. It was
a TR sports car. He went in, got on the console, and pulled his shift.
And partway through the shift the flight director got word and asked
if there anybody that had this car. John said yes. John felt like,
"What I'm doing is important, and if that's what I got to do
to get here on time, it's no big deal."
Well, apparently it got the attention of the center director, and
they pulled John's parking sticker. John was not one to kind of roll
over. So, John was this horse person. So John would come in and park
his pickup with his horse trailer on it, and pull his horse out of
the horse trailer and ride his horse on site. That got some attention
and eventually that all passed. But he was not one to give up easily.
I'll tell one other quick one about John. After one of the Gemini
splashdown parties—that was sort of a tradition and we'd go
over to a place in Webster called the Singing Wheel. I think it may
be a German restaurant or something now, but in those days the Singing
Wheel was the place to go. They had an upstairs and a downstairs,
and we usually would take over both. I'm not sure whether the regular
customers would leave. I think we kind of drove them off, because
we were pretty rowdy.
But one evening, John left a splashdown party, and he was sort of
well lubricated, and he got in his little sports car, and there had
been some fairly heavy rains, and on the way back to Alvin, one of
the big ditches, like in the area where the rice canals were, John
kind of skidded off and ended up in this rice canal with his little
sports car, and he was like up to his chest sitting in his car, and
he was just feeling good enough that it didn't really bother him that
much. He got out and waved somebody down and they pulled him out of
the little rice canal. He told them to continue pulling him until
the car started. He got the car started and took it home. That probably
ruined it. He complained to me that the thing that really chapped
him about this was that he had a new pair of shoes on. So that was
John. He was probably the most colorful.
Steve Bales, another guy, he was one of our guidance officers, a very,
very intelligent guy, but sort of an absent-minded professor-type
guy. Steve probably didn't get married until he was in his late forties.
He did get married. He married a doctor, a lady doctor. But Steve
was sort of the absent-minded professor type, and being a bachelor
through most of those years in the control center, sometimes he wouldn't
make it on console exactly on time. Like sometimes we would call him
up, if he was supposed to be on console at 3 a.m., and it was 3 a.m.
and he wasn't there, you'd call. We woke him up a couple of times.
We had recorded some of this. We had all the voice-recording stuff
and we could get playbacks of it. So we played back one of his wake-ups
one time and it was very, very humorous. We had to wake Steve up and
get him going.
Let's see. Stoval. Bill Stoval was one of our FIDOs. He and Steve
Bales were both Mensa. They were extremely intelligent guys. Stoval
was a young man from Casper, Wyoming, who came straight out of school,
very intelligent, quick study, a natural at learning. But he also,
for several of his early years, he was a bachelor. One other one,
Phil [Philip C.] Shaffer, who was a large red-haired guy, we called
him "Jolly Red Giant," because he was so big. He probably
was 300 pounds and about 6'6", I'm guessing.
But anyway, my wife and I, Joyce, we would invite [Phil and] Bill
Stoval for a home-cooked meal occasionally. On one occasion we invited
them over, and Stoval had a little sports car, one of the very early
Datsun sports car. It was called a Fair Lady 2000. Anyway, he wanted
me to help him change his sparkplugs. I said, "Oh, we can just
do that very quickly before we eat dinner."
So we get out there, and three of the sparkplugs come out okay, and
the fourth one will not come out. Now, I'm going to cut to the chase
on this one, because it's a long story. But Stoval ends up standing
in the engine compartment. One of the plugs is frozen. It's an aluminum
head, somebody's overtightened it, and crimped or set the threads.
It's like welded in there. So Stoval, and he's a young, athletic—I
mean, he's standing inside his engine compartment with this tool with
a long cheater bar on it and he's pulling. Well, the sparkplug twists
off, even with the head, so you get this part here with the white
on it, and the threaded part still in the head.
So here I've got this friend of mine at my house, we're wanting to
eat, so I'm wanting to get him out of my face. So I said, "Bill,
I don't know what in the world to do except we might be able, if we
got the right-size drill, we might be able to drill just the threads,
then we can come in and clean the other part out and put a sparkplug
So we go buy a special drill and we drill this out, and we get a magnet
down in there, and we get it all cleaned out and we put the new sparkplug
in and it's a little bit loose. Our drill had not been exactly on
center. So I said, "Bill, I don't know what to do. I'm not a
So finally I said, "The only thing I can think of is, since there's
a little bit of tolerance there, we might be able to take some epoxy
and put it around the sparkplug threads, thread it in there and then
let that harden and that might be good enough to hold the plug in
there where it wouldn't wiggle around."
So we did that, and while the epoxy was drying, we went in and had
our meal. Well, Bill starts the car up afterward, and it starts up
just fine. So he's headed home. He gets about two or three blocks
from the house and—poof! The sparkplug blows out of the head.
He lived in La Port, we lived in Friendswood, so it's about a twenty-mile
drive. So he drives his car all the way to La Port on the three cylinders
with it going, "poof, poof, poof."
I've always worked on cars. I love to restore old cars. So my reputation
as a mechanic was tarnished by this story of wanting to epoxy the
sparkplug in, but I knew of no other way to get him on his way. It's
unfortunate it didn't work. I think something we have now called JB
Weld would have worked, but the epoxy probably just got hot and cracked
and that was that. No one ever let us forget that.
I take it he eventually was able to get it fixed?
He took it to a machine shop, they had to take the head off and machine
it out and what they called a heli-coil in there, new threads and
it worked. That was probably needed from the very beginning, we just
didn't know if what we were going to do would get us by or not. It
was one of those make-do, you know, where you die trying. We died
That's right. You were controllers—
Yes, we can do it.
That's right. That's what got you through the whole Apollo Program
and everything. That's great.
That's all the questions I had.
He's pretty much talked about the one I was going to ask.
We're about at eleven o'clock now, so I don't want to keep you any
longer today. Would it be possible to give you a call? There's certainly
a lot we haven't covered with Shuttle.