_Eyes Toward Space_
In mid-1957 two severe hurricanes struck the X-15 project within
a matter of weeks. As they roared through our working space, we
launched a series of crisis meetings beneath battened hatches. Again
Stormy leaped in, bringing his authority to bear. The airplane
was well along by then. Manufacturing had begun the difficult
experimental welding of the Inconel X skin metal; other engineers,
after prolonged agonizing, brain-numbing conferences, had finally
set the design for the complex fuel tanks for the rocket engine. At
that stage in X-15 history the slightest change in one part of the
airplane ricocheted throughout the entire structure.
The first storm was a request from the customer to add additional
instrumentation devices to record the effects of wind, temperature,
and G load on the airplane. Charlie Feltz announced this new request
one morning at a meeting.
“What they want among other things will double the instrumentation
load, from 800 to more than 1500 pounds,” he said. We sat silently,
each mentally calculating the loss in X-15 performance. The news fell
over us like a death sentence. Charlie Feltz later told me he was
ready to quit.
“What do they want?” someone asked.
“Well,” Feltz said heavily, “they want some more stuff in the
instrument bay, and they want us to put in hundreds of pressure
pick-ups, strain gauges, and thermocouples, and six manometers of
archaic vintage. They want this stuff not only in the wing but also
in the horizontal and vertical tail.”
“Why didn’t they say so before now?” one of the engineers said.
I closed my eyes and visualized the new request as it would finally
show on the airplane. The thin wing would be pitted with tiny holes.
Clusters of steel tubing, pencil size, would run from these holes
and crowd through the wing root to the data-collecting manometers in
the instrument and engine bays. As the X-15 whipped through the air,
each of these tiny holes would have a story to tell, to relay through
the tubing to the recording manometers. To install these pick-ups,
and to route the tubing to the proper place through the thin wing
was a terribly tough and delicate engineering job, comparable to
engraving the Lord’s Prayer on the head of a pin. In the aft end of
the ship the pick-up tubes would have to be arranged in some kind of
infinitely complex universal joint because the horizontal elevator
rotated.
“Ah, to hell with them,” an engineer said. “Let’s don’t do it.”
Although Feltz was deep in the dumps, this comment, which to him
bordered on treason, brought him to his feet. As always, he spoke
slowly and calmly.
“I guess we have to remember this isn’t _our_ airplane. We’re
building it for the customer. He knows all the facts. He isn’t dumb.
If he wants these pick-ups, then there must be a good reason. I’ll
try to talk them out of putting them in the horizontal tail, but
we’ll probably have to settle for the others. He knows what the extra
weight will cost him. But let’s remember it is _his_ decision, not
ours. We have to do what they want.”
Charlie was correct in making that point and his timing was good, as
well. All of us had become so intensely wrapped up in the project
that we frequently tended to think of the airplane as our own
personal property. We resented any new suggestions and intrusions,
the same way a parent becomes irate when somebody else corrects
his child. We sometimes lost sight of the fact that the X-15 was a
nation-wide project, conceived for the good of the entire industry,
and that the customer had certain prerogatives which were denied us.
“God only knows,” Feltz went on, “where we can cut out some weight,
but we have to do it. The engine weight is up again, and this hurts
us even more.”
He began to detail some weight-saving ideas he and the structural
engineers had recently conceived. One was a new arrangement for the
fuel tank-plumbing that would save a hundred pounds without seriously
affecting the overall center of gravity of the airplane. The second
was a plan to install the nose wheel telescoped on the plane, saving
considerable space and weight.
The nose-wheel concept--Feltz’s own baby--was new and appealing. It
greatly reduced the nose-wheel storage space and saved us half a
hundred pounds or more. Few people realize it but the landing-gear
apparatus alone on some airplanes can account for as much as eight
per cent of the total weight. With our lightweight rear skids and new
nose wheel, the gear on the X-15 made up only about one per cent of
the entire weight of the airplane, or a total of 300 pounds.
The second storm struck a few days later. It was more severe
in force, but as I think back on it now it helped the project
tremendously. But when it first came we thought it might delay us
fatally. Again the news was passed out at a meeting in Feltz’s office.
“Now, you won’t believe this,” he started out, “but the customer
wants to change the mother plane.”
A chorus of groans echoed through the office.
“The customer says the B-36 is being phased out of the Air Force
inventory. Spare parts will be hard to come by, maintenance on the
B-36 is staggering, and so on. They want us to use a B-52.”
The B-52, a monstrous eight-jet bomber, then being manufactured
in quantity by Boeing, was designed to replace the B-36. The
substitution of this new mother plane immediately raised grave new
problems, which we batted about in the meeting.
“You can’t put the X-15 in the B-52 belly,” an engineer said. “The
landing gear is in the way.”
“I know,” Feltz said. “We’ll have to hang the X-15 externally, out on
the wing.”
This concept in itself was extremely controversial. For some
years the Air Force had been conducting experiments with external
stores--the Rascal missile, for example--on high-performance
jet airplanes. The appendage completely modified the overall
configuration of the aerodynamic shape, and added drastic new
problems to the already tough job of piloting a jet in the
trans-sonic zone. The planes vibrated and the stores shook loose, or
else produced so much drag that the original anticipated performance
of the airplane was never reached. We were now asked to hang the
largest external store ever conceived on a B-52--with a man in it.
The wing-mounted X-15 and the use of the B-52 as a mother plane
presented great new operational troubles. The pilot would have to
board the X-15 before the mother plane took off, for example. The Lox
top-off system would have to be not only remote but automatic, as
well, because no mechanic could crawl out on the B-52 wing to adjust
it. The B-52 flaps, which provide extra lift, could not be used on
take-off because the X-15 tail would be in the way. Some means would
have to be devised for a visual check on the X-15 in flight. There
were no side windows in the B-52. We would have to put a switch in
the X-15 so the pilot could launch himself if anything went wrong.
This was not all. As conceived, the X-15 would be suspended from a
pylon on the right wing, between the B-52 fuselage and the first, or
inboard, engine pod. The “flutter and noise engineers,” especially
a lady engineer at North American named Rose Lunn, who had a habit
of being right, challenged this method, pointing out that the noise
from the B-52 engine pod might seriously damage the X-15. Feltz
set in motion detailed studies to determine the full extent of the
vibration effect. The engineers strapped a dummy model of the X-15 on
a B-52 wing and ran the B-52 engines for ten hours. Concrete ballast
representing the weight of the X-15 was hung on the B-52 wing and
dropped to see what effect it would have on the bomber. There was
much juggling back and forth. In the end we beefed up the X-15 tail.
The X-15 nose was mounted ahead of the B-52 wing leading edge, so the
X-15 pilot could eject if necessary.
It was not easy to locate a couple of spare B-52 bombers for this
mission. Air Force General Curtis LeMay, then boss of the Strategic
Air Command, needed every airplane he had either for training or
for the active deterrent force. But at last the Air Force located a
couple of ancient B-52s, the third and eighth planes built, which
were not rigged for combat. North American converted them, installing
the X-15 mating pylon, automatic Lox top-off system, and remote TV
sets, mounted to give the launch-panel operators in the B-52 a full
picture of what was going on out on the wing.
Air Force Captains Gahl and Charles Bock were designated mother-plane
pilots. They perfected a system of horsing the giant airplane into
the air carrying the X-15 load without flaps. When Gahl was killed
in another airplane, Captain Jack Allavie, a test pilot at Edwards,
moved in to take his place. Both Allavie and Bock were superb
aviators.
After this work was well along, Charlie Feltz said: “You know,
Scotty, I think we might come out ahead on this mother-plane switch.
Luckily we can save a loss in the schedule. With the B-52 we can
launch a little higher and a little faster, and in the long run, this
will give back some X-15 performance. I think we will also get back
some of what we lost on the added instrumentation.”
I had to agree. Although the shift caused great technical pain, it
paid off.
* * * * *
The new mother-plane launching scheme came at an interesting and
provocative time in U. S. aviation history and set us to thinking
in terms of even more exotic X-15 launching vehicles. Far-seeing
engineers in the industry were beginning to turn their eyes toward
space. The power of rocket engines had increased enormously. The
Atlas missile, plus boosters, had a thrust of 450,000 pounds. The U.
S. had already announced a plan to put a basketball-size satellite
into orbit to gather data for the International Geophysical Year.
Russian scientific publications hinted that the USSR might orbit an
object even sooner. Engineers were beginning to talk seriously among
themselves about putting a combat vehicle into orbit. Primarily as
an aero-medical experiment, Air Force General Don Flickinger asked
industry to look into an orbiting capsule which could support a
chimpanzee and, perhaps later, a man. This project was labeled MIS,
for Man In Space. The North American Advanced Design Section was busy
drawing up plans.
Good-natured but intense debates on the proper course to follow in
space exploration broke out among the engineers. Some engineers and
scientists claimed space travel was nonsense. Others, especially
the Army’s Redstone group in Huntsville, Alabama, urged that it was
necessary to retain our freedom. The majority of us knew that man
would go into space simply because space was there. At that time few
could anticipate the psychological impact of space triumphs on the
world.
Charlie Feltz, Stormy, and I spent many hours after work at the
plant discussing the coming space age. I think we agreed on all
aspects of space exploration (Stormy eager, Charlie thoughtful, and
me ready). The first step, we surmised, would be the launching of
unmanned, highly-instrumented space devices to gather information on
gravitational forces, radiation patterns, meteorites, communications,
and unusual environmental conditions expected in space.
Following these probes, man himself would go there, no matter what
the cost in terms of money and scientific effort.
“If the Russians get to the moon first,” Feltz said, “it will be a
heck of a note. And who knows what’s up there? The moon might be
solid gold. Think what that could do to the economy. Think what
you might find out if you set up an astronomy lab in that clear
atmosphere. We might change our entire concept of the origin and
nature of the universe.”
“I think the military phase of it will be important,” Stormy said.
“You don’t know what you will run into until you go there. We might
turn up some whole new concept which will make our present defenses
inadequate.”
Talking in these heady realms naturally led into a discussion of the
hardware that would take man into space.
“The moon thing is a long way off,” Stormy said. “You’d have to build
a space station to orbit the earth first, and take off from there.
Within the state of the art of power-plants, the thrust to offset
gravity of the earth alone would make a non-stop earth-moon trip
unfeasible.”
“You’ll need some kind of space ship to commute back and forth
between the orbiting space station and the earth,” I said. “Something
you can control in space, shift orbits with, so you can pull
alongside the space station and all that. And you’ll have to be
able to re-enter the earth’s atmosphere and land, like an airplane.
Personally, I can’t see this coming out of orbit with a parachute on
a capsule. I’d want to fly in and out. Makes a lot more sense to me.”
“I feel pretty certain the first experimental steps will be something
like Flickinger’s MIS project. A brief orbit flight in a capsule,
then a slowing down, and re-entry automatic, with a parachute.”
“Yeah,” I said. “But you’re liable to land in the ocean, or any
place. Pretty undignified way to come down, I’d say.”
“True, Scotty,” Stormy said. “But, as I said, that is the logical
starting point to see how man reacts to the new environment. Later
on, we would get into your commuter space ships. Something like an
X-15, perhaps. As a matter of fact, why not the X-15? We’ve got
the capability to go into space, the systems, rocket engine, and
full-pressure suit. What would happen if you put the X-15 on top of a
big rocket booster like the Atlas? Or, say, the Navaho?”
The Navaho was an intercontinental-range, air-breathing missile,
which had been conceived by the Missile Division of North American.
The Navaho was mounted piggy-back on an enormous three-engine
rocket booster which developed about 415,000 pounds of thrust. The
building of this booster had pioneered North American’s way into
the rocket-engine field and ultimately provided the U. S. with
a reliable rocket engine for Redstone, Jupiter, Thor, and Atlas.
It had also led to the development of a very reliable automatic
inertial-guidance system, which was later used by the Nautilus on
the submarine’s first submerged voyage under the North Pole. But
the Navaho vehicle itself had been overtaken by technology--by the
superior ballistic missiles.
“You’d have some terrific aerodynamic heating problems,” Feltz
replied. “The X-15 as it now stands doesn’t have the capability of
anything much above Mach 7. You’re talking now about Mach 20 and
above.”
“But the basic vehicle is there,” Stormy insisted. “The power-plant,
the shape, the internal systems, the communications, the instruments,
the landing gear, pressure suit, escape system, and all the rest.
What you’re talking about is simply a beefing-up of the skin to
resist heat, aren’t you?”
“Yeah, heck, I guess I am,” Feltz said. But I could tell what he was
thinking. The skin would add weight, the higher heating loads would
call for greater air conditioning for the instruments, and back we
would be again in the maddening battle of weight versus thrust.
“It would take a new airplane,” Feltz said. “The shape would be the
same, but a new airplane, I think. Of course, we’re organized to
handle it. We have the only rocket-airplane team in the country in
being. We know this thing backwards and forwards. And like you say,
it’s just a question of beefing it up. Yes. We could do it. I don’t
think it would take long.”
“How long?” Stormy pressed.
“Two years,” Feltz said. “Two years from right now.”
Stormy added figures in his head, then he scribbled on a piece of
paper. Soon we were all scribbling on pieces of paper--envelopes, I
think they were.
Stormy said: “With a Navaho booster system and X-15 second stage, we
could reach Mach 12 two years from now, or 1959, say early 1960 at
latest, right?”
“Right.” We confirmed his figures. My mind was spinning, trying to
visualize an X-15 perched atop a Navaho booster on a launching pad,
then blazing skyward at twelve times the speed of sound. At that
speed it could zoom deep into space and cover a distance over the
earth of perhaps nine thousand miles. Such a vehicle would have the
capability of flying from a U. S. base to Russia and beyond. It could
be a combat weapon, I thought.
“It’d take a lot more to get into orbit,” Feltz said. “A new
booster concept and a new X-15 altogether. Same shape but different
materials. You’ve got a Mach 25 re-entry problem to contend with.”
“We can get to that later,” Stormy said. “But if we’ve got to have a
commuting space ship, why not get started on the initial step-by-step
program now? We’ve got the team to do it. We’ve got half a dozen
Navaho boosters lying around gathering dust in the attic.”
“Stormy, you can’t go proposing that to Washington. Hell, we haven’t
even flown this airplane yet. Mel Apt flew Mach 3 and died doing it.
Now you’re talking about leaping to Mach 12. They’d just laugh at us.”
“I won’t make a formal proposal, Charlie,” Stormy said. “I’ll just
feel them out about it. If we can get the speed, we ought to be after
it. The concept has military potential, a weapons system, something
like the German boost-glide bomber idea of World War II. It’s a
logical course to my mind. I’ll maybe put the thing through as a
change-order.”
“A change-order?” Feltz laughed. “A $90 million change-order?”
Stormy talked it up in Washington informally, but the customers,
while intrigued by the idea, were reluctant to move into an advanced
X-15 project before the ship had proven itself in flight. Stormy
argued that the flight experience itself was a logical stepping-stone
toward an advanced X-15. While the X-15 was being debugged in flight
test, the more advanced model could be coming along. By the time the
latter was ready to fly, the original X-15 and its machinery would be
a proven, reliable concept, as safe as an ordinary jet fighter plane.
But in those days before Sputnik, money was scarce and most space, or
semi-space, projects, taboo by order of Secretary of Defense Charles
E. Wilson.