NASA Johnson
Space Center Oral History Project
Edited Oral History Transcript
Thomas
J. Kelly
Interviewed by Kevin M. Rusnak
Cutchogue, New York – 19 September 2000
Rusnak:
Today is September 19, 2000. This interview with Tom Kelly is being
conducted in his home in Cutchogue, New York, for the Johnson Space
Center Oral History Project. The interview is Kevin Rusnak, assisted
by Carol Butler.
I’d like to thank you for having us into your home today.
Kelly:
You’re quite welcome.
Rusnak:
If we could start off with you telling us something about your background,
maybe some of the interests you had in either aviation or engineering,
kind of growing up and getting into college.
Kelly:
When I was a kid, I made airplane models and flew them. So I was kind
of interested in planes. I won a Grumman [Aircraft Engineering Corp.]
scholarship when I was a senior in high school, which paid my college
tuition and it also included a summer job at Grumman every summer.
So I started at Grumman in the summer when I was kid, seventeen years
old, and worked in the shop for two or three summers and then got
into engineering for one or two summers. So I was pretty well indoctrinated
into aerospace by the time I graduated from Cornell [University, Ithaca,
New York].
Rusnak:
From there, after you spend your student summers, as you said, working
in the shop and that kind of thing, once you graduate, did you go
to Grumman as a full-time employee?
Kelly:
Yes. Yes, I started out working on their supersonic ramjet-powered
missile program, called the Rigel. That was a Mach 2 missile, ‘way
ahead of its time. This is like 1950 or something. So that was kind
of fun, and that program was canceled before it was really completely
finished, although we did some test flights. Then I worked on some
of the latest fighter airplanes. We had a supersonic fighter by then,
too, the F-11F [Tiger].
I worked on the propulsion systems, the inlets and exits, supersonic
propulsion. So that was fun. But then I had to go into the Air Force,
because I had been in the Air Force ROTC [Reserve Office Training
Corps] at Cornell. So after five years at Grumman, I went into the
Air Force to the aircraft lab at Wright-Patterson Air Force Base [Dayton,
Ohio]. I worked on quite a variety of projects. The Air Force had
a lot of new airplanes under development at that time. It was the
mid-fifties. So that was pretty neat. I got to visit all the companies
in the industry, just about, and work on some of the latest programs.
So that was a fun time.
While I was there, the Russians sent Sputnik up, so then I got interested
in space. When I got out of the Air Force, instead of going back to
Grumman, I went out to Lockheed [Aircraft Corp.] in California, Palo
Alto, because they had a Space Division out there that I wanted to
work with. So I had about a year out there, got kind of a basic grounding
in space from people who were really working at it, but my Grumman
pals kept after me to come back to Grumman, and they told me they
were going to start a space operation, space group.
They finally talked me into coming back to Grumman, which I did, and
I got in their newly formed space group. I worked on a couple of their
proposals, one of which was successful. It got us the Orbiting Astronomical
Observatory [OAO], which was really the forerunner of the Hubble Space
Telescope. The same idea, just a somewhat smaller telescope. That
was a very successful program. I didn’t actually work on the
program once we won it.
They asked me to investigate this program to land men on the Moon,
that NASA was talking about. This was in 1960. So I went around and
talked to a number of people including, George [M.] Low and Ed [Edgar
M.] Cortright, who were kind of involved in the early studies and
considerations of the Apollo Program.
I reported back to Grumman and said, “Hey, this thing is really
moving along and it looks like it’s going to be a big program.
We'd better get with it if we want to compete on it.” So we
formed a small engineering group to study the lunar mission, and I
headed that up. I guess we had about ten people at first, but it kept
picking up and gaining momentum.
In May 1961, President [John F.] Kennedy officially announced we were
going to go to the Moon. Then it became a very big deal for the industry.
NASA had a pre-bidders' conference where they described the program
and the bidding process they were going to go through. So we tried
to get positioned to compete on that. By that time we probably had
fifty people working on it.
When the RFP [Request for Proposal] came out from NASA for the Apollo
spacecraft, at that point our company leadership got cold feet. It
just looked like too big a job for Grumman. So they said we couldn’t
bid it as prime. We had to get on somebody’s team and do a piece
of it. So we got a berth on the General Electric team. We were responsible
for most of the command module. It was a big competition. I guess
that was 1961. But we lost. North American Aviation [Inc.] won. And
there we were.
Rusnak:
How much direction from NASA did you have at that point in terms of
the design for the command module, or was this left pretty much up
to the contractors to figure out?
Kelly:
They had pretty well specified the shape of the command module and
the size. So the basic design they had established. What they hadn’t
done was figure out how they were actually going to perform the mission.
They really hadn’t worked that out at all. So after we lost
the job, we began looking at the various ways to do the mission, and
pretty quickly convinced ourselves that lunar orbit rendezvous [LOR]
was the best approach.
We did some studies of that and showed them to NASA. NASA had been
doing similar studies. In fact, we went down to Langley Field [Langley
Research Center, Hampton, Virginia], I remember, on Pearl Harbor Day.
It must have been 1961, that was right a month after the award to
North American. We went down and met Dr. Bob [Robert R.] Gilruth and
Max [Maxime A.] Faget and their group, Owen [E.] Maynard, Caldwell
[C.] Johnson. All the guys that were working on Apollo were down there
at that time. That was before there was a Houston. [Laughter]
We showed them what we’d been studying and why we thought lunar
orbit rendezvous was the best approach, and they agreed with us. They
had come to the same conclusion. So we had a very good session with
them that day. They gave us a lot of encouragement to hang in there
and maybe compete for the lunar module, which was going to be required
if that’s the way they went.
So we did. We helped them decide to go lunar orbit rendezvous and
then we competed for the lunar module and won it as a result of maybe
two years of solid work on it.
Rusnak:
What was it about lunar orbit rendezvous that really made you think
that that’s the way we were going to get to the Moon?
Kelly:
It had two very appealing attributes. One is, it was the most efficient
way to do it. You could do it with a single launch of the Saturn V,
and the competing schemes like Earth orbit rendezvous or direct descent
all required at least two launches. So it was the most efficient.
The other thing it did that was really good was that it divided the
mission tasks between two specialized spacecraft that had very different
requirements. The command module was totally dominated by the need
to reenter the earth’s atmosphere, so it had to be dense and
aerodynamically streamlined and all that, whereas the lunar module
didn’t want any of that. It wanted to be able to land on the
Moon and operate in an unrestricted environment in space and on the
lunar surface.
It ultimately resulted in a spindly, gangly-looking, very lightweight
vehicle that was just the opposite of all the attributes of the command
module. If you tried to do that all in one vehicle, it would be a
real problem. I don't know how you would have done it. But this way,
with this mission approach, it was very neatly divided in two halves.
Rusnak:
When you won the proposal, what did your initial design for the LM
[lunar module] look like?
Kelly:
Well, that was an interesting thing. The NASA made it very clear in
their bidders' conference and in the RFP that they weren’t buying
a design as a result of the competition at all. They didn’t
think anybody knew how to design the LM at that point, and they intended
to work with the contractor to develop the design jointly after the
award.
Now, for the proposal, if you wanted to show them a design just to
illustrate your points and your knowledge of the mission and all,
that was okay, but they weren’t buying that. We did, of course,
show them a design, and it was similar in concept but different in
just about every detail from what finally evolved. It was a two-stage
vehicle with the two crew members in the upper stage (ascent stage)
and a lot of propellant and equipment stowed in the descent stage,
[and] landing gear in the descent stage. But all the details were
different from what ultimately evolved.
Rusnak: The way you describe working with NASA not buying a design
but buying this team and this expertise, that’s a little bit
different than the way, say, Grumman might have worked with the military
as a contractor designing a plane or something.
Kelly:
Right. It’s even different than the way NASA worked on many
programs. Even the OAO they pretty much specified the basic design,
anyway. But this was different.
Rusnak:
So what sort of challenges did that present for you guys in this proposal?
Kelly:
It was a lot of fun, actually. Owen Maynard was the Chief Engineer
for the NASA when we started. He had been one of the guys working
with Faget and Gilruth up in Langley. He was a good guy to work with
and he had a lot of knowledge himself and his people about the LM
and the mission. He worked very compatibly with us and contributed
a lot, he and his people, to the evolution of the design.
In fact, I used to kid him. We said that he had in his desk drawer
a drawing of what the LM ultimately should look like. Now, would you
please show it to us so we can avoid a lot of the folderol we’re
going through? Now, he did have some designs, but he wouldn’t
show them to us because he didn’t want to over-influence us.
He wanted us to be free to develop our own ideas. So it was a cooperative
effort for, I’d say, the first year until the full-scale mockups
were finalized. We were evolving the basic design. I have some diagrams
that can show you the before and the after, actually some pictures
if you want to see them. Let me get them.
Rusnak:
Even coming up with something like this basic design for the proposal,
even though you know you know it’s probably not going to be
the final version, doing this process is something that hasn’t
been done before. You’re creating the first spacecraft. How
do you go about thinking about how to do something like this versus
creating an airplane or whatever else?
Kelly:
Well, it was really a lot of fun. We just pretty much let our imaginations
run wild and let the form follow the function. It just kind of evolved.
You basically started out with the two astronauts, and you had to
wrap everything around them or design everything so that they could
get at it and use it. Then the ascent and descent stage split was
something that we had to work out. It was very desirable to put as
much stuff in the descent stage as you could because it saved weight.
[Tape recorder turned off.]
Okay, where we were?
Rusnak:
You were talking about thinking about designing a spacecraft in form
following function.
Kelly:
Oh, yes. So it was just a lot of fun. We had sessions where we’d
get up on the blackboard and sketch different ways of doing things.
I remember one session that went on pretty much all day where we looked
at different ways of positioning the attitude-control thrusters and
finally worked out the arrangement that we used. One of the main things
that made the design change from the proposal was the need to get
reliability, and we did that by adding redundancy where we could,
and where we couldn’t, by making the system just as simple as
we possibly could.
In the process of simplifying the systems, we realized that we had
just fallen into accepting some basic things that weren’t necessary,
like symmetry. We found out that we originally had four-propellant
tanks in the ascent stage because it gave us a symmetrical configuration.
Then we said, “Gee, it doesn’t have to be symmetrical.”
We could get down to a single tank each for fuel and oxidizer, but
then you had to offset them by different amounts, so the LM ended
up looking like it had the mumps on one side.
So we did things like that, that gradually changed the design. When
we got to the full-scale mockup, we were able to work with the astronauts
on both the crew station and the means of getting to and from the
lunar surface. On the crew station, the big innovation was, originally,
in our original design, we had a lot of glass in the cockpit and the
crew was seated. I didn’t like glass because it was heavy and
not too reliable as a structural material, so I was after my people
to try to get rid of the glass, and in the process they came up with
the process of getting rid of the seats. That put the pilot’s
eye, when he was standing up, very close to the window, so he could
have a very small window and still have a wide field of view.
Our people worked with the NASA people on that. Our guys were John
Rigsby and Gene Harms and Howard Sherman. They worked with George
[C.] Franklin and some others, NASA people in Houston, and they really
jointly developed this LM crew station that was a standup flight station.
So they were standing up right in front of the instrument panels,
holding onto hand controllers. They had some foot restraints they
could put their feet into, and they were held down by a restraint
harness that kept them from floating up in the air. That worked out
very well. It was very compact and gave us a small window area, which
was something we were looking for.
So the astronauts were able to evaluate that in the full-scale mockup,
which was about a year after we started the program.
Rusnak:
Do you remember what their reactions were to this?
Kelly:
They liked it. We had been working with a couple of them all along,
and they liked it on paper. When they got to try it out, they liked
it, too.
The other thing we worked with them on was how you get to and from
the lunar surface. There we had a variety of schemes. We had a block-and-tackle
scheme and some kind of hokey stuff, but we ended up with a very simple
arrangement with a platform on top of the landing gear and then the
ladder going down.
We worked particularly with astronauts Pete [Charles C.] Conrad [Jr.]
and Ed [Edward H.] White [II] in developing this lunar surface egress
arrangement. We had a rig we called a Peter Pan rig. It was hooked
up to the big traveling overhead crane in the final assembly area,
and we could lift five-sixths of the weight off the astronaut. So
it was an attempt to simulate the one-sixth G lunar surface conditions.
They had some fun getting that to work, but it was helpful after a
while and helped us develop a lunar surface arrangement.
In the process, we had to enlarge the front hatch and make it rectangular
instead of circular, the way we had it originally, because they had
to come out with their backpacks on, which gave them a very rectangular
cross-section as they were going through the hatch.
Rusnak:
The front hatch was also originally used as a docking port?
Kelly:
Yes. In our proposal, we had proposed that you could get redundancy
in the docking by making both hatches docking hatches, but that didn’t
go very far because North American had already started working on
a probe and drogue docking arrangement. The astronauts liked it because
it was similar to the Air Force probe and drogue refueling arrangement
with which many of them were familiar in flight.
The other argument was that if you couldn’t dock, you could
still transfer EVA [extravehicular activity] from the LM to the command
module. So it evolved that we really didn’t need the front hatch
to be capable of docking. And it was a good thing, because we had
to make it bigger and rectangular in order to do the lunar egress
part of the mission properly. We did add an overhead docking window
so that you could use the overhead hatch conveniently in docking.
Rusnak:
One of the other things I was wondering about is the technology that
goes into the landing gear since the LM is going to be going down
on a surface that, at the beginning, you don’t really know what
the surface is going to be like. Is it going to be big pools of dust
or hard and rocky? So how do you go about designing gear for a surface
you don’t really know what it’s going to be?
Kelly:
Well, we had a very wide range of assumptions about the lunar surface,
anything from deep dust to hard ice and everything in between, slopes
and all that, curbs. So we designed for a combination of these things.
We did establish what the maximum touchdown velocities would be. That
was ten feet per second vertical and four feet per second horizontal.
So with those as the maximum velocities, we also assumed a specific
maximum slope of the surface. I think it was six degrees.
With those assumptions, then you layered on the different assumptions
about what the surface itself was like. We went through hundreds and
hundreds of computer simulations of different combinations of the
touchdown conditions and the lunar surface assumptions, and ultimately
picked the tread width and landing-gear height that we ended up the
final design. I think we assumed two-foot-deep potholes and two-foot-high
boulders could be in the area too. So we had all those assumptions.
We did a load of computer runs on that, and finally knitted it together
into the design that resulted in the final version.
I didn’t want to have fluid in the landing gear, because I was
afraid of developing a leak if you had either liquid or gas fluid
in the compression strut. So even in the proposal I said, “No
fluid. We’re going to have a solid energy absorber.” The
absorber that we came up with was basically aluminum honeycomb. It
was just a [deep] cylindrical slug… of aluminum honeycomb material,
which you could crush and it would absorb a lot of energy, but it
had no fluid in it at all. That worked very well in all the testing
we did of it. In the actual missions, the astronauts set the LM down
so gently every time, that we hardly ever compressed that strut at
all, just a couple of inches, usually, whereas it had, I think, about
eighteen inches of stroke that it could have absorbed. So, yes, the
landing gear was a very interesting design.
When we adapted the cruciform descent-stage arrangement, it worked
out nicely because the landing gear support points were also the support
points for the LM inside the spacecraft LM adapter [SLA, pronounced
“slah”].
Rusnak:
What about in terms of stowing the legs to fit in the SLA on the Saturn
V?
Kelly:
Well, all I needed was a one-shot extension and then lock in place,
which was pretty easy. It was a spring-loaded arrangement. So we had
them fold in like that, here they are folded, and they just swung
out and snapped in place for the mission.
Rusnak:
One of the other areas I wanted to talk about was the thermal protection
system.
Kelly:
Yes. The LM had to have a very lightweight thermal protection system.
In fact, the LM had to be very lightweight in general, because for
every pound that we took down to the surface and brought back to orbit,
we had to add over three pounds of propellant. So it was like a four-to-one
growth factor for weight. So that’s what was driving the LM
to be so lightweight.
Well, we had to thermally isolate it from the space environment, because
in space it’s basically 250 degrees in the sun and minus 250
in the shade. We couldn’t stand that, so we basically wrapped
the LM in a very thin aluminized Mylar cover that in a vacuum operated
like a vacuum jacket. So the whole LM was wrapped up in that multi-layered
aluminized Mylar cover. We combined that with the micrometeoroid protection
by putting a thin aluminum shield on the outside…of it.
So we had a combination of meteoroid protection and thermal shielding
which was very lightweight. It was something you had to be careful
with on the ground, because it was very delicate. But that’s
basically what it was, filled in with the multi-layer insulation blankets.
Rusnak:
How well did this design work structurally when you were first trying
to make this function?
Kelly:
It worked very well. We didn’t really have any problems with
it. It was strong enough that it didn’t tear itself apart in
the G loads, mainly because it was so light, but it was also very
effective as a thermal insulator.
We tested a full-size LM. It was called LTA-8, LM Test Article No.
8. That was tested in that big thermal vacuum chamber in Houston,
full size, and with the astronauts inside for part of the mission.
We put it through the complete thermal paces. It had heaters on it,
heater strips, and the chamber had cold walls, so we could simulate
any combination of thermal conditions that we were going to get on
the mission. It performed very well in those tests. We were quite
confident when we went into the mission that we wouldn’t have
any thermal problems, and we didn’t.
Rusnak:
Speaking of part of the test regimen, one of the things I was wondering
about was, what was the testing program developed for the LM to get
it qualified for flight?
Kelly:
Well, every component, major component in every system had to be qualified
against its spec, and then the LMs themselves were tested extensively
before they were ever used. In fact, we practically wore them out.
We tested them for two years for a three-day mission. [Laughter] So
they got an awful lot of testing. We basically ran them through all
the mission paces and through a lot of failure modes as well, over
and over again. We did it at Bethpage [New York]. We did it again
down in Cape Kennedy [Florida] before they were put into the launch
stack. So they were very extensively tested.
The flight crews participated in the testing, because many of the
tests required a pilot in the cockpit to manipulate the controls and
take action of various sorts. So there was a load of testing. That’s
what they were doing most of the time in Bethpage. It didn’t
take long to assemble the vehicle, but it took a long time to test
it.
Rusnak:
Who’s dictating the testing that goes on? Is it Grumman, NASA,
or a combination of both?
Kelly:
I guess it was a combination, but basically we just tested everything
you could think of to test, everything that you knew you had to do,
and then as many of the failure modes as you could reasonably simulate,
we tested. It was a buildup program. We gradually built it up to more
and more complex tests until finally we were going through the whole
mission.
Now, it took about 40,000 engineering drawings to design both the
LM and all the ground support equipment that went with it, so there
was a lot of engineering effort at the peak. We had over 3,000 engineers
at Grumman working on the LM and its support equipment. There were
a couple hundred items of ground support equipment that we also designed
and built specially for the LM. So it was a lot of work. We had to
have a big push to get our drawing releases up, and at the peak we
were pushing out over 500 drawings a week, engineering drawings. So
you don’t think of it as a big design job, but it really was,
because every detail had to be worked out.
Now, we also had a big problem with the weight of the LM. The weight
grew rapidly from the initial proposal and then for the first couple
of years of the program, primarily as a result of adding the reliability
provisions, the extra redundancy and that sort of thing, and also
from gaining a better understanding of the mission requirements.
Anyway, the result was that by after about two and a half years into
the program, we were busting through the weight ceiling, and things
were pretty tense because the Saturn just couldn’t take any
more. It couldn’t grow any more. So we had to basically go back
and reexamine the whole design and redo whatever we could to reduce
the weight.
So we had a program, we called it the Super Weight Improvement Program.
I was personally in charge of that as the Chief Engineer because I
went over all the designs and reviewed ways that we could change and
simplify them. It was a very intensive effort for about six months,
but it was successful. We stopped the growth and eventually we got
the weight down…
That was a big effort, and it did result in a number of changes, some
of which got us into trouble later on. One of the changes was, we
went to the lightest wire we could get for signal wiring that didn’t
carry any current, 26-gauge wiring. And that damned wire was so fragile
that our technicians just had to handle it with kid gloves. It was
breaking all the time whenever you mated or de-mated a connector or
what have you, so it was a big nuisance in the manufacturing process.
The wires didn’t break as a result of mission vibrations or
forces, but they sure broke easily in the handling. That was a pain
in the neck. We finally got a higher-strength copper alloy for the
26-gauge wire that was less prone to break. We were able to phase
that in, I think after LM-5 or LM-6. Made our life easier.
Another thing that we did for weight reduction was we went very extensively
to chemical milling, where you chemically milled out the aluminum
or metal surfaces, both sheet metal and machine parts. We did a lot
of that, because we would chem mill right down to the bare minimum
thickness that you needed in each particular area. That got us into
trouble later on, because the chem milling left the surface exposed
or open and more vulnerable to stress corrosion. We started to get
stress corrosion cracking problems, and we had to have a fairly concerted
program to inspect for stress corrosion cracks and also to replace
some of the items or parts that were most likely to crack. So that
was another unforeseen fallout of our weight-reduction efforts.
Rusnak:
Since you had mentioned the wiring and how with your very thin-gauge
wiring it was very easy to break in handling as the technicians are
working on it, in terms of where wiring got the command module into
trouble on the Apollo 1 fire, I was wondering what impact that event
had on the lunar module program.
Kelly:
Well, the command module problem, a good bit of it was the way they
had done the wiring. They had a lot of rat’s nests. It was just
a mishmash of wiring. We didn’t do that. I mean, we were smart
enough from day one to know you should neatly comb out your wires
and make it so you could tell whether you had a good secure wiring
arrangement or not. We had to go over our wiring, and if we had any
rat’s nests or areas where there were a lot of wires jammed
together, why, we did have to change that. But we didn’t have
too much of that.
However, there were a lot of materials changes that affected us in
the crew compartment. We had to get rid of all nylon and we had to
do things like adding fire-retardant covers, booties, we called them,
over the backside of the switches on the panels, because the backside
of the switches were plastic switch material that was quite flammable.
We had to add these booties and then put a potting compound on top
of that, which was fire retardant. So there [were] a lot of things
like that that we had to do which weren’t too big a change in
themselves, but again they did tend to slow down the production and
testing process, and they made it very difficult to change anything.
Once it was all potted in, it was a big deal to pull it all out and
change something.
So we got hit somewhat from the fire, but not too badly. They made
some strict rules about having a support tie every four inches on
each wire bundle, and we hadn’t done that before. We had them
at random distances. So we had to go back and change that, that sort
of thing.
Rusnak:
This graph of the LM weight shows a fairly steady increase until the
beginning of 1967 and then it starts to jump up and kind of goes up
from there before it flattens out again. I’m assuming that was
as a result of some of these materials changes and that sort of thing.
Kelly:
Do you mean this over here?
Rusnak:
1967, I guess. It’s going down and then it starts to kind of
go back up. The fire would have been right in about there.
Kelly:
Yes, but the other thing that happened about that same time was they
approved an extended-stay LM which was heavier, it was allowed to
be heavier, 4,000 pounds heavier than the previous LM. It could stay
three days on the Moon instead of one, and it could carry the Lunar
Rover and more scientific equipment and lunar sample return payload.
So those changes were in there, too.
Rusnak:
One of the pieces of hardware that we haven’t talked about yet
is the propulsion system, both on the ascent stage and on the descent
stage. Both of them, I understand, had some issues in terms of their
development and such, so if you could talk about that for a little
bit.
Kelly:
…The ascent propulsion system lifted the LM ascent stage off
the lunar surface and brought it up into rendezvous in lunar orbit
with the command module. This was obviously such a vital system that
we sought to make it as reliable as possible by making it as simple
as possible. It was a constant, fixed-thrust, pressure-fed engine.
There were no pumps with hypergolic propellants, so there were no
igniters. There was an ablative-cooled nozzle, plastic nozzle, so
there were no intricate cooling passages. It was just as simple as
we could make it, and yet it did have a serious problem of combustion
instability.
There had been a big problem with combustion instability on the huge
one-and-a-half-million-pound-thrust engine for the Saturn V, and that
problem had caused several explosions during tests and it had taken
over two years of intensive work at Marshall Space [Flight] Center
[Huntsville, Alabama] and by Rocketdyne [Division of North American
Aviation] before they finally got the combustion instability solved.
So NASA and we were very aware of the hazards of combustion instability.
In the course of solving the Saturn problem, they developed what they
called a bomb stability test, where they set off an explosive charge
in the operating rocket engine to try to induce instability. Otherwise,
you just had to wait for it to happen spontaneously, which was very
unsatisfactory. So NASA decided, and we agreed, that our engines both
ascent and descent stages, should go through these bomb stability
tests. The descent engine never had any trouble with it, but the ascent
engine did. The bomb stability test required that after you set off
the explosive, the pressure spikes should damp out within, I think,
four-tenths of a second.
In the case of the ascent engine, the pressure spikes didn’t
damp out at all; I mean, they just continued. They didn’t get
any worse, but they didn’t damp out either. So it was kind of
a strange thing. It didn’t have the kind of instability that
the Saturn engine had, [which] just got progressively bigger and worse
until it exploded. But on the other hand, it couldn’t pass the
bomb stability test either because the spikes never went away once
you started them.
So after some debate, we decided that…was not acceptable, that
we had to get the ascent engine to pass the rigorous test criteria.
There was…no formula for how you make a rocket engine stable.
It’s very complex. It involves the injector pattern and flow
rate and propellant ratios and many other things that all interact
together. So it’s basically a cut-and-try process. We did a
lot of cutting and trying, but we weren’t getting anywhere.
It still had that same characteristic [and] couldn’t get through
the bomb stability test.
So NASA got impatient and directed us to get another contractor involved.
Bell Aerospace had been our ascent engine contractor. We also brought
Rocketdyne along, too. They both worked on versions of the ascent
engine. Neither one of them was completely successful, but in the
end, a combination of the Rocketdyne and Bell designs was put together
by Rocketdyne and it was satisfactory. It was able to get through
the bomb stability test, and everything else about it was okay, too.
But that took quite a while, took a couple of years, and for a while
the LM asset engine was on the infamous "showstoppers list,"
something that was potentially [able] to stop the whole Apollo Program
if it didn’t get fixed.
The descent engine didn’t have stability problems, but it was
more complicated because it was variable thrust. It had to be in order
to effect a landing. The rocket engine could be throttled all the
way down to 10 percent of full thrust, which was a first at the time,
first time there had been such a high degree of throttle-ability in
a rocket engine. They did it by having a movable pintle in the injector
head, so we were actually changing the spray pattern and the flow
rate of the injector. Considering all the innovations that…required…it
went very well. Most of their problems were mechanical in nature,
getting the movable pintle to work smoothly and go where it was commanded
and that sort of thing. But it just…never had the stability
problem, which was a really much more frustrating kind of problem.
So although the ascent stage was simpler, the development of it was
more difficult.
On the reaction control system, we were able to borrow heavily from
the reaction control system that was used on the command and service
modules. We basically used the same 100-pound thrusters that they
used, and we followed a lot of the design techniques in the system
design. That was kind of a [hand] off….
Rusnak:
With the ascent engine, one of the things it’s doing is when
it first lights off, it’s using this fire-in-the-hole technique
where it’s sitting on top of the descent stage. What sort of
issues did that bring up?
Kelly:
Well, we wondered about that a lot, because nobody had really ever
done that before, light up a rocket engine with a plate of sheet metal
right in front of the exhaust [nozzle]. We just didn’t know
what was going to do, but we tried it in tests many times out at White
Sands [Test Facility, Las Cruces, New Mexico]. We had a test facility
that we operated for NASA out in White Sands, New Mexico, and we could
fire our rocket engines out there. We had a rig where we could do
fire-in-the-hole testing.
We didn’t really notice much effect from having the plate there
in the way as long as we moved the engine pretty quickly up out of
there, so the test results were encouraging. Analytically we couldn’t
show a problem. And when it got to flight-testing, that was one of
the things that we did on both the unmanned LM, LM-1, and Apollo 9,
which was the first manned LM flight, and in neither case did we see
any particular problem with this fire in the hole. So it was a cause
for question and concern. We did devote a lot of time to looking at
it and testing for it, but in the end, it turned out not to be really
a problem.
Rusnak:
I’d also like to cover some of the internal subsystems of the
LM, like the environmental control system and the guidance system
particularly.
Kelly:
Okay. The environmental control system was similar to, but different
from the command and service module. It was designed by the same contractor,
Hamilton Standard, but the components had to be different because
it was supplying two men instead of three with a different geometric
arrangement. We also had the requirement of emptying out the cabin
every time we went out on the lunar surface. So we had to have quite
a bit of gas aboard just to refill the cabin every time they came
back in.
There were some weight problems with the environmental system, and
we had a pretty complex packaging arrangement for the major components
that were inside the cabin, and those things took some development
time and effort. But in general, the environmental control system
was pretty well behaved.
The guidance system was—well, we had the primary navigation
guidance system, which was basically designed and supplied by MIT
[Massachusetts Institute of Technology, Cambridge, Massachusetts].
They supplied it to both the command module and the LM with different
software to go with it. The amount of computing power just seems ridiculously
small by today’s standards. I think it was like 36,000 bits
per second, something like that, minuscule compared to what you’ve
got on your laptops today. But that’s what we had, so in order
to conserve the bits, they programmed everything directly in machine
language, so only experts could touch the programming of the guidance
system.
So MIT supplied the primary system. We supplied what was called the
abort guidance system. It was the backup to the primary system. It
only had the capability to abort and get you back to the command module,
in the event the primary system failed. We never had to use it for
real, although we used it in tests a lot. In fact, it got us into
trouble a couple of times when it was mistaken for the [primary] system.
That was designed and built for us by Space Technology Laboratories,
STL.
Rusnak:
Up to this point we’ve talked a lot about the hardware involved
with the LM, so I want to ask you about some of the other people who
were involved, particularly on the Grumman side. Who were the people
that you felt were key in this and the people that were your managers
and the other people that were overseeing the program, that kind of
thing?
Kelly:
Joe [Joseph G.] Gavin [Jr.] was the Vice President and Director of
the whole LM program for Grumman. The Program Manager initially was
Bob [Robert S.] Mullaney. He reported to Joe Gavin. Then the Engineering
Manager was Bill [C. William] Rathke. He was the Lead Engineer, and
I was the Project Engineer. I reported to Bill. That’s the way
it started out. After about two or two and a half years, Mullaney
left the program and Rathkey became the Program Manager and I became
the Engineering Manager. So that was the hierarchy. Now, I had three
project engineers reporting to me, assistant project engineers. Bob
[Robert W.] Carbee was in charge of the design subsystems, the design
groups. Arnold [B.] Whitaker was in charge of the analytical subsystems.
John Coursen was in charge of the ground support equipment, as we
did all that design, too.
Another key player with me was Eric Stern, who headed the Systems
Analysis and Integration Group, which in the beginning was very key
in putting together the overall concepts for the LM. Beyond that,
we had engineering section heads in each of the technical disciplines
and they were all key players. There were about a dozen of them. Manny
[Manning] Dandridge was the propulsion section head. That was a very
key job. Ozzie Williams headed the reaction control system. Don McCloughan
was the environmental system, and Ross Fleisig on the guidance navigation
control and so forth. We had a list of key players there.
In addition, when a particular problem arose, we often appointed somebody
to fix that problem. That sometimes took a lot of work and a large
group of people to do it. One of the problems was leaks in the fluid
systems, particularly the propulsion systems. Will Bischoff, who had
been a Deputy Head of structural design…was tagged with trying
to finally fix our leaks, which had been a problem for many years.
Leaks were something you were never completely 100 percent free of,
but we did make a lot of progress with Bischoff’s efforts. So
there were a number of things like that.
Our engineering activities at Kennedy Space Center were headed up
by Herb Grossman. He was our launch systems engineer and Kennedy systems
engineer…
Where were we?
Rusnak:
We were talking about some of the people at Grumman.
Kelly:
Right. George [M.] Skurla was the leader of all the Grumman activities
down at Kennedy Space Center. He interfaced directly with [NASA Kennedy
Space Center Director] Rocco [A.] Petrone, so he had a tough job keeping
Rocco happy and making sure that everything went well on the LM. We
were the last contractor down there, so we got a lot of attention
because all the other guys had been there and knew the ropes. But
we did all right. We got onboard and up to speed pretty fast.
Rusnak:
Rocco Petrone was at NASA first and then obviously went down to the
Cape. There were also a number of NASA people at your own plant, including
the resident manager and such, so if you could comment on some of
those and how the relationship worked there.
Kelly:
The local NASA manager, let’s see, the first one, I guess, was
Small. Jack Small or John [W.] Small [Jr.]. They were more administrative
in nature. They handled all the paperwork and led us through the major
formal activities that we had to go through with NASA. Of course,
we had a lot of NASA inspectors, quality-control inspectors that were
out on the floor all the time participating in all the activities
and witnessing and signing all the papers that certified we’d
done things according to the book and what have you.
The engineering contact was more informal and it was directly with
Houston. As I mentioned, Owen [E.] Maynard was initially the NASA
leader, and then there were others, Bill [William F.] Rector and Bill
[William A.] Lee. Bill Lee was assigned by NASA to be my counterpart
during that Super Weight Improvement Program, so he spent a lot of
time up in Bethpage looking at the weight reduction items and activities
that we were involved in.
So we got to know a lot of the NASA people, engineering people. During
the missions, we supported the mission out of the Spacecraft Analysis
Room, which was right across the hall from the main Mission Control
Room. Either I or Carbee or Whitaker were usually in that Spacecraft
Analysis [SPAN] Room. That was the top-level room for the spacecraft
contractors. We were only allowed to have two people in there at any
one time. North American was in there also and MIT and some NASA people.
But we had access to everything on the mission. We had control consoles
and all the instrumentation readouts and the headphones that gave
us all the nets. So we could be fully active in supporting the mission.
There was another building about three blocks away, Building 45, I
think it was, where they had a much bigger room and we were allowed
to have about a dozen engineers up there, so we had one for each specialty
in that room. They also had all the similar access to the mission
information. Then in Bethpage we had a Mission Support Room of our
own, where we could bring in as many people as we liked and also bring
in our subcontractor people and we could contact our subcontractors
all over the country if need be.
So depending on how much time we had to work a mission problem, [if]
we only had a couple of minutes, why, I would do it right from the
SPAN Room, Spacecraft Analysis Room, we called it. If we had a little
more time, we’d get the people in Building 45 [Mission Evaluation
Room, MER] involved. If we had plenty of time, hours, we’d get
Bethpage and our subcontractors across the country involved. We did
that, for example, on Apollo 13, where at one point it became very
critical to know exactly what the consumption rates of power and water
were for each actual piece of equipment that was on that LM. We didn’t
want the general spec value; we wanted to know exactly what [it] was
on that particular piece of equipment.
So we had to have our subcontractors and suppliers look it up wherever
there’d been a test run. If there hadn’t been a test run…they
ran one. So that was a big supporting effort that went on for a day
or so and was quite helpful. But there were a lot of things where
we were able to get help and ideas and plug them into the mission
with beneficial results.
Rusnak:
Let’s talk about some of the flights that the lunar module was
on. Let’s start with the first unmanned test flight.
Kelly:
The first unmanned test flight got off to kind of a rocky start, because
the idea was to control the flight through the LM mission computer,
and they had preloaded all the instructions into that. But there was
a software error in the very first activity, which was a descent engine
burn and it shut the descent engine off early. But the backup was
to control it manually through the LM mission programmer. Gene [Eugene
F.] Kranz writes about that in his book. They did that very well.
They had practiced how they would use the LM mission programmer if
they had to, and they did have to because of this software mistake,
and they were able to pull off the entire mission. They got every
mission objective, so it worked out to be a totally successful mission,
even though there was this glitch right at almost the very beginning.
With LM-1 being successful, it did demonstrate fire in the hole. By
the way, that was the first flight demonstration of fire in the hole.
So it basically went through the abort stage sequence, jettisoning
the descent stage and firing up the ascent engine simultaneously and
then completing a rendezvous, and it went through all that in orbit
unmanned. That was very successful.
As a result, we did not have to fly LM-2, which was the backup unmanned
LM. I think LM-2 is the one that’s in the Smithsonian Institute
right now. It was refurbished to look like Apollo 11 when it landed
on the Moon.
Then the first manned LM was an earth orbital flight, Apollo 9. That
was Jim [James A.] McDivitt and Rusty [Russell L.] Schweickart. They
basically did everything you could do in Earth orbit to simulate the
lunar mission, including a rendezvous from starting about 115 miles
away from the command module. It all went very well, except Schweickart
got pretty sick for the first couple of days, but we didn’t
even know anything about that. They always kept anything about the
astronauts’ personal problems pretty secret and switched over
to a guarded channel. So we didn’t even know he was having a
problem. We just wondered why they were cutting short some of the
activities and EVAs and all that. But then after the mission we found
out what the story was. Anyway, he recovered enough to basically perform
all the most necessary parts of the mission, so it turned out to be
highly successful.
Apollo 10 was a flight to the Moon, but not landing on it. There was
some debate as to why they should do that, why not just land, but
there was enough concern about the details of the gravitational differences
of the Moon, the real Moon, versus the models that we’d been
using. Also that LM was kind of overweight because we didn’t
think it was actually going to have to land on the moon, so we didn’t
put all the weight-reduction items into it. So, I guess, a combination
of things. They flew the entire mission except for the landing, simulated
the landing. It was very successful, and they had basically no problems
that amounted to anything.
Rusnak:
Just a bit of a tense moment with the wrong guidance system selected,
I think.
Kelly:
Yes, there was a moment where the LM kind of went bananas. It was
thrashing around wildly, and it turned out they had flipped the switch
into the wrong position for guidance, and it was trying to do something
it couldn’t do at that point. So when they flipped the switch
back, which they did just before we figured out that that was the
problem, everything straightened out again.
Rusnak:
The next flight, of course, was Apollo 11.
Kelly:
Apollo 11 was the culmination, and it was pretty exciting. There were
a couple of things happened during the descent that basically happened
so fast that we didn’t really get involved with them. They had
to be dealt with instantaneously.
One of them was the program alarm that they got. Fortunately, a couple
of the NASA controllers had studied the MIT program alarms that were
built into the software and they had basically memorized every one
of them. There was a long list of them. All it did was come up with
program alarm and then a number, Program Alarm 28, and you had to
know what that meant. Well, nobody knew what it meant except these
two guys that had studied it, and they knew what it meant and they
told Kranz, “No problem. Go ahead.” So he did. They later
found out why they got the program alarm, but it really was no problem.
The other problem was the computer was directing them to a field full
of boulders, so [Neil A.] Armstrong had to take over and steer it
around. By the time he did all that, he almost ran out of fuel. But
they got down with thirty seconds to spare or something like that.
They made a nice gentle landing and everything worked great.
Then we had a little panic right after the landing. About three or
four minutes after landing, we noticed that the pressure in the fuel
line leading to the descent engine was going up pretty rapidly, and
this was a segment of line between the fuel to helium heat exchanger
and the shutoff valve on the head of the engine. What had happened
was the fuel had frozen due to a surge of cold helium after the engine
shut down. The fuel had frozen in that heat exchanger so it made a
solid block on that end of the line. The other end was blocked by
the engine shutoff valve. As the heat soaked back from the shutdown
engine, the pressure and temperature in the line was going up pretty
fast.
We didn’t like that, because if it got up about 400 degrees…the
fuel could explode, go unstable. There wasn’t much fuel in there,
just vapor, but still, we just didn’t like the idea and we were
nervous about it. So we had some very hasty consultations with the
NASA people and our own propulsion people, and we finally decided
we were going to burp the engine. We were going to ask the astronaut
to flick the engine on and then off right away, just to relieve the
pressure in that line. We didn’t think it would start up enough
to [cause] any problem.
George [M.] Low had gotten with us in the SPAN room, and he had bought
this scheme. The capcom, the capsule communicator, was just about
to tell the astronauts about it when the problem solved itself. The
ice plug in the heat exchanger melted by itself, and all of a sudden
the pressure dropped down to zero, so no problem, it went away. But
we sweated that out for about ten minutes right after the landing.
People ask me how did I feel after the landing, and I tell them, for
the first ten minutes, I was too busy to know where we were, whether
we were on the Moon or what. When we finally figured out that we were
there, it really was a pretty intense moment. We were very curious
as to what they would find, so it was very interesting when they got
out on the surface and took pictures, showed us what they found.
That was the first landing where we saw how gently they set it down.
It hardly even stroked the landing gear at all. They all did that,
by the way. They’re very good pilots. So from there on, it was
just neat. We watched them take all the stuff out of the LM and set
it up on the surface, experiment with how you could walk around on
the Moon and all that. It was all brand-new and very exciting.
Rusnak:
At that point, you had only really fulfilled only half of Kennedy’s
goal. You still had to get the guys safely back.
Kelly:
Right. Well, the ascent part of the LM mission was pretty tricky,
because you had to simultaneously disconnect the descent and ascent
stages, which meant firing about eight different explosive devices
and fire up the ascent engine at the same time. So if you thought
about it, there was a lot that could go wrong. But the saving grace
was it all happened in an instant so you knew right away whether it
worked or not. Fortunately, every time it worked, everything fired
and off they went.
Once they were on the way up…it was very smooth. They didn’t
have a problem at all. When I talked to a couple of the crews after
the missions, they told me the ascent was just like riding in an elevator
in a building. You knew you were moving, but you didn’t feel
a whole heck of a lot of acceleration, which was kind of amazing because
they were standing right in front of the rocket engine. But they didn’t
feel much vibration or anything.
Rusnak:
With each of the succeeding missions, they’re getting a little
bit more complex in terms of the activities that are going on, the
longer stays, the precision landings, that kind of thing.
Kelly:
Yes. I tell you, Apollo 12 was kind of an amazing mission. I mean,
that thing got hit by lightning. It was kind of amazing they even
fired it off under those conditions. But having done so, and having
it get hit by lightning, I think we were very lucky that nothing really
went wrong.
The LM wasn’t so vulnerable at that point because it was still
tucked away and inert inside the spacecraft LM adapter. But the command
module and the service module were hanging right out there and they
got the full dose. It did knock everything off the line at first,
but they were able to get it back on pretty quickly.
They made the first precision landing of the program. After the first
mission…NASA decided that they needed to be able to land more
precisely, and they developed a technique for doing that. To prove
it on Apollo 12, they wanted to land right near Surveyor, which was
an unmanned spacecraft that had been sent up and landed there a couple
years earlier. And they did it. They plunked it down within a couple
hundred yards of the Surveyor, and it was very impressive. They walked
over to Surveyor and took pieces off it and all that. That was the
beginning of the ability to do precise lunar exploration.
Pete [Charles C.] Conrad [Jr.] was a fun guy to work with. He was
one of the most expressive of the astronauts. He had worked with us
on the lunar surface egress and the Peter Pan rig stuff, so we got
to know him a bit when he was up there doing that. Then we got reacquainted
with him when he was up testing his LM, and he greeted us like long-lost
buddies. He was just a neat guy to work with, so I was very glad to
see him recover from that mission the way he did. I thought he did
a great job.
Then came Apollo 13. Of course, that’s a story in itself. On
Apollo 13 I had basically left the LM program at Grumman. They had
decided that after seven years and the program having successfully
landed on the Moon, that I could use a little R&R. So they sent
me up to MIT, the Sloan Fellows Program for a year. So I was up at
MIT when Apollo 13 was launched.
I got a call around midnight from a Grumman colleague of mine who
was also up in Boston at Harvard, Howard Wright, and he told me to
put on the radio and listen to what was going on with Apollo 13 and
then to meet him down at Logan Airport, because Grumman was going
to send a light plane up for us to get us down to the Mission Support
Center in Bethpage.
So I did that and I arrived down in Bethpage about three in the morning
and stayed there working nonstop for about the next three days, with
a little nap once in a while… We helped NASA determine exactly
what the consumable requirements would be. We also helped them evaluate
different techniques for realigning the platform with a minimum amount
of power and things like that.
There was quite a lot to do. One memory I have of that, when I arrived
at 3:00 o’clock in the morning and I was approaching the front
door of Grumman, there was a whole crowd of engineers coming in with
me. It looked like it was 8:00 o’clock in the morning, the start
of a normal shift. [They were] all just people who had heard what
was going on and just decided to come in and see if they could help.
That was pretty great. And it was good because we did need the help.
Of course it had a happy ending. Again, we didn’t know how bad
things were, because anything personal about the astronauts was not
revealed to us or anybody else. So we didn’t know that Fred
[W.] Haise [Jr.] was as sick as he was. He was really in bad shape
for a while. …We knew they were cold and uncomfortable, but
there just wasn’t anything we could do about it. We had to keep
the power off because there wasn’t going to be enough to get
back. So they were pretty lucky on that one. They did make it, but
just barely, especially with Fred being sick.
Rusnak:
Had you ever done any studies or made any preparations for this kind
of use of the LM?
Kelly:
Yes, we had. We had done a mission definition series of studies the
first year or two into the program. We were trying to define—we
actually headed up a group which NASA supported and which all the
other Apollo contractors supported, to develop a basic design mission
that could be used by all the system and subsystem people and spacecraft
people as a source for their design requirements.
So in the course of doing that study, we looked at various failures
that could occur, too, and what you could do about them, and we realized
there was a whole category of failures on the outbound leg where you
could use the LM as a lifeboat and get into the LM and live off the
LM’s consumables if something had gone wrong with the command
and service module that denied you the use of their consumables. So
it was written up, but it was never developed in any detail. It was
there as a possibility, but they never worked out detailed flight
procedures for how you would do it step by step, and it wasn’t
practiced with the crews. The crews didn’t train for it or anything.
So although it wasn’t an unheard of idea, neither was it something
that was just ready to go at the spur of the moment. It had to be
worked out in detail as it went along.
Rusnak:
After the Apollo 13 flight, did you then return to MIT?
Kelly:
Yes, I went back to MIT and I was back in Bethpage by June of that
year. I did support the Apollo 14 mission, which was Al [Alan B.]
Shepard [Jr.]. I went back to Houston for that, because after Apollo
13, I decided I'd better not get too far away from things.
That was a great mission. That was another precision landing, and
that was the first mission where the astronauts really concentrated
on lunar exploration once they got there. They had done quite a bit
of field rehearsal with Lee [Leon T.] Silver, a geologist. He had
showed them how to observe from the point of view of a geologist and
taught them all the proper terms to use so they could converse with
the geologists and scientists very knowledgeably about what they were
seeing and observing on the Moon. That was very good. That plus the
ability to do a pinpoint landing made it possible for them to lay
out their whole route on the Moon well in advance and discuss with
the scientists what they were going to be looking for and why, etc.
Then when they got there, they did it and they were able to show the
scientists what was going on.
Now, it got even better on the subsequent missions when they got the
lunar roving vehicle, because that had a camera right on it and it
also had a precision navigation system right on it. On Apollo 14,
they got a little bit lost. It was very hard to find your way around
on the Moon. It was kind of an undulating surface but no landmarks,
nothing you could judge distance or height or anything by. It was
very confusing. You were never really exactly sure where you were.
Even on Apollo 12 they encountered that a little bit, but it was even
worse with Apollo 14, and there was a particular crater they were
looking for. They got to within about sixty feet of it but never really
saw it, never really knew they were there. So that was kind of frustrating.
On the subsequent missions they didn’t have that problem, because
the lunar roving vehicle carried with it a very precise navigation
system that they could load in coordinates of the route they had agreed
to take, and they didn’t have the problem of getting lost.
Also with the lunar rover they had the camera right there, so when
they found a rock that looked interesting, they’d hold it up
and discuss it with the scientists down on the ground. So that made
for a very productive exploration. [Tape recorder turned off.]
Rusnak:
You spoke to this a little bit before, but these later missions used
a modified LM for the longer stays. What were some of the changes
that were made to accommodate this?
Kelly:
Well, we were able to load more propellant in the tanks. I don’t
think we had to make the tanks any bigger. I think we already had
enough capacity in the tanks. We added batteries, made that bigger,
and took more consumables with us. We also modified the stowage bays
in the descent stage. We had to outfit one specifically for the lunar
roving vehicle, which folded up into the stowage compartment, and
make some of the others bigger so they could take more scientific
equipment. So they weren’t major changes, but it was all aimed
at increasing the stay time and the return carry capacity.
Rusnak:
With these last few missions, was your concentration then on Apollo,
or were you looking to some other things then at that point?
Kelly:
Well, I personally was off the program by then. I was involved with
our Space Shuttle activities. We were getting ready to propose on
the Space Shuttle and did propose on the Space Shuttle. But I kept
in touch with the mission up at the Bethpage Mission Control Center.
We used to work on the anomalies, they called them, that occurred
in flight, anything that was outside the ordinary. We were getting
fewer and fewer anomalies as the missions went on, but we tried to
explain every one of them when corrections were required.
Rusnak:
Did you also have anything to do with the studies or thoughts about
using the LM for some other purposes, either through modifying it
for different types of missions on the surface or, say, using the
LM for the Skylab as part of the Apollo Telescope Mount, any of those
kinds of activities?
Kelly:
We had a small group that was looking at that kind of thing, but it
wasn’t part of the basic LM program.
Rusnak:
Since, as you said, you’d moved to the Space Shuttle Program
by this point, I’d like to talk a little bit about the Shuttle
and some of Grumman’s early work in studies for the Space Shuttle.
Kelly:
Okay. We got involved with the Shuttle through Gilruth and Faget.
The initial concept of the Shuttle was that it would be fully reusable
with a two-stage vehicle, and each stage would be returned, directly
returned. This got to be pretty elaborate. They were big vehicles,
they had wings, they had turbo-jet engines and rocket engines, and
it was a pretty complex system.
NASA went ahead and funded two studies that North American and McDonnell
Douglas were given to develop that concept. But meanwhile, Faget and
Gilruth got kind of disenchanted with that approach. They decided
it was too complicated, and they wondered if there was some easier
way to do it, so they got us involved. They asked us to do alternative
systems studies. So we looked at a number of alternatives, most of
which involved taking propellant out of the orbiter stage and putting
it in the descent stage, the lower stage, and doing other manipulations
of the payload and the propellant loading.
We…worked…cooperatively with Faget and went through a
series of iterations, but eventually ended up with something that
looked pretty much like the present-day Shuttle. Instead of a recoverable
lower stage, it had an external tank that was non-recoverable, and
it had solid rockets where you could recover the case by floating
them.
So this was very promising in the studies, so promising that NASA
decided finally that that’s what they were going to do. They
cut off the work on the fully reusable system, which was pretty amazing,
because they’d done a lot of work on that, and announced that
they were going to have a competition for this new version of the
Space Shuttle.
So we were very happy with that. We thought we were in fat city because
we had worked this whole scheme up, and our competitors were going
to have to learn it and compete with us on it. So there was a hammer-and-tongs
competition, but we lost. Exactly why, I was never sure. Our design
was certainly what they wanted, but there may have been other aspects
of our program that they didn’t like as much.
So it ended up that we went to North American to see what we could
get after they won, and we got the wing. We were able to get the design
and development of the Shuttle wing. So that’s what Grumman
ended up with on the Shuttle Program.
Rusnak:
Then was overseeing the Orbiter’s wings part of your job?
Kelly:
It was, yes. By that time I was head of engineering for the whole
company, so I was in charge of the engineering work on all our projects
and that was one of them.
I felt bad about the Shuttle, because I thought we had done an outstanding
job on the LM and we hadn’t gotten into any big problems like
North American had, and yet here they were walking off with the big
prize. I never really was satisfied with that.
Rusnak:
I guess North American’s, to some degree their experience there,
just like with the Apollo, having gotten that after getting the X-15,
I'm sure played a role in NASA’s selection there.
Kelly:
Right. And NASA had gotten very closely involved with North American
after the fire, because they had to go in there in force to Downey
[California] and help them work their way out of the problem, and
in the process, the NASA people sort of became subsumed into North
American people, or at least that’s the way it seemed to me.
So for whatever reason, we didn’t get the really big prize,
but we did get a piece of it.
Rusnak:
After that point, did you continue to have some involvement with the
space program?
Kelly:
Yes, as part of the engineering activities, but Grumman was getting
less and less work in space and more and more in the advanced airplanes,
so I got more involved with the aircraft activity. But we still had
space work going. We had some work for the Air Force, study work.
We participated to some extent in the Sky Lab Program. We proposed
on a lot of stuff in space, but we weren’t outstandingly successful.
We didn’t get too much of that.
Rusnak:
As you take a look back on your involvement with NASA, what do you
think the biggest challenge you faced was?
Kelly:
The biggest challenge for LM and the whole program, I think, was making
sure the whole damn thing was going to work. I guess it was Al Shepard
said, “Here I am sitting on top of this thing that was designed
by the lowest bidder." You had to keep the cost down as low as
you could, but also you wanted to be damned sure it was going to work.
The way we assured that was to analyze and test just everything we
could think of. Whenever a test failed…we were on that like
hound dogs to find out what the cause was, what was the problem, and
fix it up. We just wouldn’t let anything go unexplained.
In fact, Joe Gavin told me he had some figures on this, that there
were over 14,000 failures, test failures, in some part of the LM program.
That would include our components and our subsystems. And at the end
of the program we only had twenty-two of those that were still unexplained
failures. So we really did work the problem very hard of testing as
much as we could and then following up on the results of the test
to eliminate any problems that they showed up. I think that’s
the reason it all worked as well as it did because they also did that
across the program pretty much.
Rusnak:
At this point, I want to give Carol a chance to ask some questions
that she may have come up with.
Butler:
I have a few. Mentioning these 14,000 failures throughout the program,
was there any point where you wondered whether you were going to be
able to get it all pulled together and to make that deadline that
Kennedy had set back in ’61?
Kelly:
Well, I never wondered if we would be able to do it or get it all
pulled together. I did wonder whether we were going to make the deadline,
because the schedule was really very tight. We were following these
procedures of testing and analyzing everything and correcting the
failures. With that basic approach and using the program management
techniques, particularly the PERT [Program Evaluation and Review Technique]
diagrams of all of the events and activities, we were able to lay
out in great detail what we had to do and then just follow up and
do it.
Butler:
When Kennedy had made the challenge back in 1961, what did you think
of it at the time and of the possibilities of making that, even though
you hadn’t been quite involved in the program yet at that point?
Kelly:
I just accepted the whole thing. I mean, I don’t remember questioning
any of it. It never entered my mind that we wouldn’t get there
if we decided to go to the Moon. That was never a concern for me.
Indeed, the technology was ready. We never had any problem that looked
like it was going to kill things. Even ascent engine instability,
we were sure we were going to get a solution, but it was a cut-and-try
thing that just took a long time. But there was nothing that looked
like it was impossible to do. In fact, it all looked pretty doable,
but you had to be attentive to detail and follow up on everything
to make sure you didn’t miss anything.
Butler: Being attentive to detail, in some of our research for preparing
to come talk to you, we were looking at the book Chariots for Apollo
by [Charles R.] Pellegrino and [Joshua] Stoff, who mentioned how everything
that was taken into the lunar module was almost marked off and everything
was checked off that could back out. Is that how intense things were
in watching those details?
Kelly:
Yes. I’m sure that was one example. We were embarrassed on Apollo
9 because some washers and nuts floated around in the cabin, and Jim
McDivitt pointed them out on TV to the world. We had already done
everything we could think of to find stuff and keep it from getting
into the cabin and staying in the cabin, but we just worked even harder
on it after that.
Butler:
Luckily it was just a few washers and things and nothing.
Kelly:
Well, yes, but, you know, it could be more of a problem than that.
We did have one problem that was a real quality problem that was on
Shepard’s flight, where we had what looked like a loose solder
ball inside the abort stage switch. That was a bear, because we had
to find a way to neutralize that or we were going to have to abort
the mission. Fortunately, MIT came up with a set of simple instructions
that told the computer to ignore what this abort stage switch was
telling it, and the astronauts were able to plug that into the computer,
and we just went ahead with the mission. But that was a quality-control
problem that we should have caught. It was a not uncommon problem,
because the instruments were all hermetically sealed and they were
evacuated before they sealed them. They sealed them with solder, and
sometimes a little bit of the extra solder would get sucked in and
you’d have a solder ball floating around inside. They could
usually detect that in the factory by shaking it and listening and
looking, but this one got through the whole thing without ever being
detected. So that was kind of scary.
Butler:
You mentioned on Apollo 11 the frozen plug in the fuel line. What
did you do for later missions, or did you change anything to try and
prevent that from happening again?
Kelly:
Yes, we changed the procedures. It was a very simple procedural change
where we didn’t vent the propellant tank right away. It was
because we had vented the propellant tank right after landing that
allowed flow through that heat exchanger that caused the freeze-up.
So just by not doing that right away, we were able to avoid that whole
problem from then on. So it was a very detailed procedural change.
Butler:
Sounds like it was a successful one.
Kelly:
Yes.
Butler:
That’s all the questions that I have. Thank you.
Rusnak:
I actually had just a couple follow-ups of my own, some stuff I wanted
to go back on.
Last week we were talking with Andy [Andrew] Hobokan about some of
his work there. He mentioned a couple of things that I wanted to ask
you about.
Kelly:
How’s Andy doing these days?
Rusnak:
He seems to be doing pretty well. He had a good time coming in and
talking with us.
Kelly:
Good.
Rusnak:
One of the first things, I guess, was just kind of a funny story he
told about a squirrel getting into the white room where the LMs were
being prepared at one time. I wanted to see what you remember of that.
Kelly:
I don’t know about that one.
Rusnak:
According to him, anyway, a squirrel had gotten into the white room
and was shot by a security guard.
Kelly:
Really? I never heard about that. But I don’t doubt it. It certainly
could happen.
Rusnak:
One of the other things he talked about was a problem with the glass
for the windows. I guess there were some issues with some of them
cracking. I wanted to see what you recall of that.
Kelly:
We had a failure during a pressure test of the cabin. I think it might
have been LM-5, where the glass actually broke, and that scared the
hell out of us. So we did some redesign on the mounting to be more
sure that we weren’t applying any stress to the glass when we
locked it into position. We also worked with Corning to develop a
stronger, more crack-resistance glass, and we did substitute that
improved glass. So, yes, we were worried about glass. I never liked
glass as a structural material. You couldn’t analyze it. It’s
an amorphous kind of thing.
Rusnak:
You certainly got rid of as much as you could there.
Kelly:
Yes. It’s a good thing we did, because even with just that simple
flat panel, we still had cause for concern. If we ever had a big curved
dome or something, we would have gone nuts.
Rusnak:
Just one last thing, I guess, to provide clarification. You had said
that you were the Chief Engineer for the LM. What was your job description
and the area of responsibilities that were uniquely yours?
Kelly:
Well, I don’t think anything was uniquely mine, because I was
responsible for all the engineering activity, but engineering was
involved in just about anything that went on in the program. So program
management was also always involved in things, too. But basically
I was responsible for the engineering and technical activities of
the program. We had a total of over 7,000 people at the maximum of
the LM program, of which about 3,000 were engineers.
Now, I did change jobs at one point. In 1967, I was taken out of engineering
and put in charge of building the LMs and the manufacturing, assembly
and test activity. So that was kind of just punishment. I had to build
what I designed, and that’s where I found out what a bad idea
some of those weight-reduction items were, because it was my technicians
then that were trying to avoid breaking those wires and things like
that. Then after that, I went into program management on the LM for
the later part of the program and for supporting the missions.
Rusnak:
That’s all the questions I had, so I just want to give you an
opportunity to make any concluding remarks that you wanted to, anything
to sum up.
Kelly:
I think we’ve pretty well covered the waterfront. It was a great
program. It got the NASA firmly headed down the path of space exploration.
Those last three missions were really very intensive lunar exploration
missions, and NASA never deviated from that path. All their subsequent
manned and unmanned missions were directed towards exploring and understanding
the world of space. So I think Apollo made a very significant contribution
in that regard.
It was very valuable in its own right, and it showed us what people
could do in space under some very demanding conditions. And we learned
an awful lot about the Moon, very interesting place, and gave us an
idea about what it would be like to possibly explore other planets
in the future as well. So it was a very successful program. I was
delighted to work on it and really very happy that it went as well
as it did.
Rusnak:
I’d like to thank you for taking the time out to meet with us
today.
Kelly:
Okay. Very good.
[End
of interview]
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