In 1949, very few aeronautical engineers were giving any thought to the possibility of turbojet engines with continuous afterburning that could produce exhaust velocities of approximately 1,400 miles per hour. In fact, there were no turbojet engines that could produce a supersonic exhaust velocity at that time.

The Ballistic Airliner had its roots in Germany's WWII V-2 ballistic missile.

To be sure, the sound barrier had been broken -- but the first time it was broken it was broken with an airplane powered by a liquid propellant rocket engine. The second time it was broken it was accomplished in a tailless swept wing (very rakishly swept back wings) turbojet driven aircraft, the British DeHavilland DH-108 “Swallow”; earlier, this somewhat unstable airplane had claimed the life of Geoffrey DeHavilland. Those were pioneering days for aviation engineers and designers in finding the best aircraft forms and suitable power plants for supersonic flight.

Not imagining the enormous advances that would be made with the turbojet engine, aeronautical engineers turned their attention to a prime mover that could easily drive an aircraft to transonic and supersonic velocities. The Germans had stunned the world with their V-2 short range ballistic missile. In the V-2 rocket, the Germans had perfected a very powerful and relatively reliable liquid propellant rocket engine. Compared to the supersonic turbojet engines that would come nearly two decades later, this power plant was very simple, and could be scaled up by designers to produce any amount of thrust required for any applications that might need that higher level of power.

Not imagining the likelihood of an aircraft like our modern Concorde supersonic airliner, the engineers turned their gaze on the V-2’s rocket motor. Into their fevered imaginations came the vision of a larger V-2 engine, approximately ten times as powerful as the unit in the V-2. And they hatched what seems, in retrospect, a rather absurd idea: “Let’s build a fast airliner that can vault into space into a fractional orbit, and glide to a landing after leaping between continents. Let’s build a really high speed transport.”

Hence, in the late nineteen forties, and the early nineteen fifties, aeronautical engineers began thinking of designing and developing a combination aircraft/spacecraft that would accomplish what could essentially be described as “ballistic flight”, carrying passengers that would presumably pay quite well to be whisked very quickly between continents.

I believe most of these engineers knew, deep down, that passengers would not find a ride on this vehicle comfortable; Probably only the young and adventurous would have wanted to venture into outer space for about forty minutes for such a quick trip over considerable stage lengths.

A Hypothetical Flight

Let us consider what a flight would be like in one of these “airliners”.

The ship would perhaps be emplaced, initially, on a cradle that held it horizontally, making it appear a little more benign, a little less like a “rocket ship” (“space ship”). This would perhaps help reduce what probably would seem like an intimidating first appearance of the vehicle when first beheld by the passengers boarding it: it would look something like the first turbojet driven airliners.

Once they were strapped in place by the polite and congenial flight attendants, the captain would perhaps brief them on what to expect: the profile of the flight, how it would feel when the ship was climbing under power, and how they would feel when the large, single rocket engine stopped running. This latter feature of a ballistic airliner, I believe, would have deterred most from buying a second ticket when they wanted to travel quickly. For their next trip they probably would have chosen to fly on a Vickers Viscount turboprop airliner, or perhaps a Comet jet airliner. The Comet would soon experience its own developmental disaster that would ruin its reputation, dooming it to failure, commercially.

The hydraulically operated cradle would next lift the ship into a vertical, or near vertical position for take-off. Perhaps there would be a classic countdown; perhaps there would be a display screen at the front of the passenger cabin to show the passengers such data as the time being counted down towards engine ignition and lift off, and then following with the ever mounting speed and accelerating G-forces.

A first generation liner such as might be expected to enter service would be relatively modest in size; it might carry about 40 passengers, and have an all up take off weight, fully fueled and loaded with passengers and baggage, somewhere between 370,000 lbs to 410,000 lbs.

The single large liquid propellant rocket engine would light up and run at ignition and pump r.p.m. control verification at idle thrust for about four or five seconds. This procedure is still practiced for most liquid propellant rocket engines to this day.

We would have expected that at this point, the passengers would be very excited, hearing the engine idling, and knowing that they were momentarily going to be in for the “roller coaster” experience of their lives. Presently, the engine would throttle up to about 580,000 lbs of thrust, and the ship would leave its launcher rather briskly and almost straight up. The G-forces would be considerable right after the moment of takeoff- but the passengers would be in for a surprise, because before the engine cut out approximately ninety seconds later they would be experiencing nearly 9 “Gees”: nine times the force of gravity!

I suspect that most of them would not find this a very pleasant experience, even though they would be lying on their backs, in the best position to handle the acceleration, physically. They probably would not “black out”; rather, very likely most of them would briefly “grey out”- that is to say, the lack of adequate blood supply to the retinas of their eyes would give them “tunnel vision” briefly.

Let us look at the flight of a ballistic airliner shortly after its take off from Long Island, New York. The liner will be headed for San Francisco. It is late evening, the sun having already set in one of the boroughs where the space port is located. With the reliability and safety of the rocket liner thoroughly demonstrated, rocket ports would have been as likely to be located in metropolitan areas as ordinary airports have now come to be.

One can imagine little boys (and perhaps a few little girls) occasionally playing “hooky” from school to witness the dramatic takeoff of one of these large and very loud rocket liners.

The ship would almost certainly have employed hypergolic fuels and leave a very prominent and long exhaust plume- just the kind of show children love to witness. These young onlookers would no doubt have been filled with longing to ride on one of the rocket liners. How many of us remember as youngsters hanging around the airport, longing for a ride in one of the beautiful big airliners? Certainly my brother and I made it into a major hobby as little boys- even when we were older, and at university, we would routinely visit the large airport (Will Rogers International) at Oklahoma City, and go out on the tarmac to watch the very smoky Lockheed “Electra” turbo-prop airliners coming in for landings. They would be trailing long plumes of black smoke- and we were really no longer children then. But the little boy inside each of us still loved airplanes and flight; those little boys inside each of us never perished- we both went on to become pilots.

How much more thrilling it would have been for us to have witnessed and heard the mighty roar of a rocket liner taking off for Vancouver, British Columbia, or New York, had the dream of the ballistic airliner come to pass. Let us follow the flight of the rocket liner that has just departed Long Island. The sun has only been down at the rocket port for about thirty minutes. The ship has been in flight for less than thirty seconds and is now accelerating at almost five times the force of gravity, and is high enough to again be in sunlight. The ship is going to overtake the sun as it flies west. It took off almost vertically but has slowly tilted over during its climb. It is now at about a 49 degree angle to the horizon, but continuing to slowly lower its nose as it climbs. When the rocket motor finally stops, it will be at the required 45 degree angle for maximum range during the coast through its fractional elliptical orbit.

At this point in the flight, the liner has already used up a significant fraction of its fuel, and is therefore lighter than at takeoff. For the passengers, this means a feeling of a heavy weight on their chests that is getting heavier every second. Some of them are probably not comfortable with this, and I suspect that they will not want to ride on the west coast rocket again.

But some of the passengers will be thrilled with the ride! Probably some of the younger and more adventurous passengers are not at all nervous or anxious, and are thrilled at the manifestation of the enormous power of the big single rocket engine propelling them at close to five times the earth’s gravity at this instant.

However, things are changing fast in the climb. The ship’s tanks are emptying very quickly! As they empty, feeding their Nitric acid and Hydrazine into the voraciously hungry engine, the ship accelerates ever faster.

Finally the ship is nearing the end of its powered run. It has generated tremendous power as it has accumulated the required velocity to coast through space for a large portion of the way to the west coast. Even the pumps which deliver the fuel to the engine provide several thousand horsepower to drive the fuel into the rocket thrust chamber.

If the passengers who found the nearly five “Gees” uncomfortable earlier were stressed or anxious then, think of their discomfort now: the ship is accelerating at over nine times the force of gravity!

Some of the “youngsters” will find this oppressive weight on their chest exciting in some way, understanding that it is a manifestation of enormous man-made power.

Now the ship is nearly at the end of its powered run. Will those who experienced their surprised unpleasantness be relieved by the cut-off of the rocket engine? Perhaps they are thinking that they will. However, we think they will not be pleased in any way when the engine stops running. On the other hand, some of the younger passengers will find the transition from over eight times the force of gravity to no gravity exciting and thrilling.

Almost certainly the engine will be programmed to shut down in steps, with the thrust reducing in increments rather than all at once, though it must of necessity not be allowed a very long interval in which to do this. Shutting down the engine gradually will ease the transition from nearly 9 Gees to zero gravity for the passengers. Nevertheless, some of them will not only be surprised by the feeling of zero gravity, but in fact will be appallingly frightened by it: zero gravity feels exactly like falling! The ship is in fact now actually falling as it follows the path of its nearly parabolic shaped leap through space. It is now in “free fall”, exactly as a baseball is in free fall after it has been pitched.

Some of the passengers are likely to be sick, immediately. Perhaps some of them prepared for the expected unpleasantness of high acceleration and transition to zero gravity by taking some patent medicine for motion sickness. The youngsters who were yearning for adventure, however, will probably be hugely excited by the shut-down of the engine and the transition to zero gravity.

After an interval that carries the ship up to its maximum altitude of around five hundred miles (it will be above central Nebraska at this time) it will begin descending, approaching the atmosphere for its long glide to the San Francisco rocket port. By the time the ship has descended to an altitude of about 250 miles, it will be nearly over the Nevada-Utah border.

After the long glide to the San Francisco rocket port, the pilot will manage his powerless landing on the special, long runway for the rocket liner. This early vehicle would have lacked the kind of powerful computers that we currently use to help our modern space shuttle manage its kinetic energy precisely. The pilot of our rocket liner would therefore have probably used aft mounted air brakes very frequently to bleed off excess energy, although always staying “high” on his approach to the runway: his fuel tanks are empty, and he cannot go around for a second approach.

What is the matter with this picture of the world’s first type of “ballistic airliner”?

To begin with, landings would be very risky. A proposal was thought of at the time to include “air breathing” engines for powered cruise in the air; with these turbojet engines, the pilot would be able to fly the very much lightened liner with confidence and safety to the threshold of the runway. An example of a concept for such a liner is shown below:

This kind of liner, however, would not have been a “true” ballistic airliner, but rather, a sort of “hybrid”: a relatively conventional turbojet driven airliner that could manage a brief hop into space for shortening the trip. In fact, the aircraft would not even have been able to fly supersonic while under turbojet power, lacking the adequate power jet propulsion units that still lay in the future. But it would certainly have been able to make quicker trips than the soon to enter service turboprop and early turbojet airliners.

The Death of the Idea

Why did the ballistic airliner concept die a quiet death -- actually, why was it never seriously considered? The reasons, in retrospect, are pretty obvious now.

In the years immediately following the Korean conflict, the early technology for supersonic airplane flight was developed. This technology rapidly advanced, and the concept of a turbojet driven supersonic airliner began to be considered seriously by aerospace engineers and designers. They properly understood that people were already accustomed to the “rigors” of conventional aircraft travel; or, in other words, people were used to regular airplanes.

Rocket ships, on the other hand, would have been something of a gamble, considering the unpleasantness that the flight would have imposed on most of the passengers. Realistically, one would not expect the public to be quite that adventurous- the airlines could hardly have expected the common traveler to have wanted to become, in essence, even if only briefly, an “astronaut”.

The beautiful and well engineered Concorde airliner made its debut in due course, and performed very well. The Concorde demonstrated the safety and reliability of supersonic air transport for the public. By the time it entered service, it was the most thoroughly tested airliner ever produced.

The digital revolution obsoleted the Concorde; businessmen no longer needed to conference in the same physical location. It is so much more economical of time and money to conference via the internet, and so the Concorde finally passed into history after a nearly flawless career, marred by a single accident after nearly thirty years of service.

And the ballistic airliner? It never was.