In the early thirties, inventors from several countries at once took up the topic of the so-called. rocket mail - special missiles capable of carrying mail or light cargo. From a certain time, American enthusiasts joined the race. In the shortest possible time, several variants of a mail rocket with certain features appeared and were demonstrated. The first version of such a system in the United States was presented by the inventor Fred W. Kessler - he managed to get ahead of competitors by several months.
In the early thirties F. W. Kessler was the owner of a small philatelic shop in New York. Probably, it was this fact that led to the fact that he was able to quickly learn about successful foreign experiments in the field of missile delivery of letters. Like many other enthusiasts, Kessler became interested in the new idea and set to work on its implementation. At the same time, unlike competitors, he decided not to use a traditional type of rocket. The best results, according to the inventor, could be shown by an unmanned aircraft with a rocket engine.
1936 postcard dedicated to the experiments of F. W. Kessler. Photo Hipstamp.com
Quickly enough, Fred Kessler managed to find like-minded people who could help him with the implementation of a new project. The idea of rocket mail interested J. G. Schleikh - junior - an official from the small community of Greenwood Lake (New Yore). He also moved in philatelic circles and could not pass by a promising idea. Aeronautical engineer Willie Leigh was another participant in the project. Shortly before that, he had moved from Germany to the United States, fearing the new authorities in Berlin, and was in search of a new job in his specialty. In addition, some other specialists and even commercial companies were involved in the work on the project.
It should be noted that many people took part in the creation of the first American rocket mail, taking on certain responsibilities. However, this project eventually gained fame only by the name of the enthusiast who came up with the basic proposal - Fred W. Kessler. Unfortunately, other project participants did not receive such an honor.
The first successful mail missiles were simple powder-powered products and could only fly in a ballistic trajectory. F. Kessler and his colleagues decided that this version of the mail delivery system did not have great potential. In this regard, they offered to load letters and postcards into a special rocket plane. In addition, in order to improve the real performance, it was decided to abandon solid fuel engines that are not capable of generating thrust for a long time.
Mail rocket plane Gloria I on the launcher, February 23, 1936 Shot from newsreel
The enthusiastic designers faced quite difficult tasks. Nevertheless, among them was a professional aircraft manufacturer who had experience in creating real technology, and in addition, there was an opportunity to involve other organizations in the work. Thanks to this, by the end of 1935, it was possible to complete the design of a new rocket plane, an engine for it and launch vehicles of various types.
The Kessler-Schleich-Lei mail rocket plane was largely reminiscent of the planes of its time, but had a number of characteristic differences. First of all, they consisted in the design of the product, the composition of the units and the purpose. So, it was proposed to build an aircraft with a normal aerodynamic configuration with a straight high wing and tail of a standard design. Inside the fuselage were the cargo hold and liquid fuel tanks. The engine of its own design was placed in the tail.
In connection with the need to obtain a high weight return, as well as due to the presence of flammable substances on board, the mail rocket plane was decided to be made with the broadest use of metal. Steel and a copper-nickel alloy were used in the frame and skin. A relatively simple fuselage truss was built with a constant rectangular cross-section and streamlined profile. On the sides, the frames of the planes were fixed on it. The entire frame was fitted with a thin metal sheathing.
The head of the aircraft contained the payload. Shot from newsreel
F. Kessler and his colleagues have developed their own rocket engine. Since the rocket plane was supposed to show a high flight range, it was decided to equip it with a liquid fuel engine. The actual engine, made in the form of a tube of large elongation, was in the tail of the aircraft. The engine design did not provide for its own ignition means. It was planned to use a conventional torch to start the combustion.
Inside the fuselage - under the wing, near the center of gravity - there were cylindrical tanks for fuel and oxidizer. The fuel was a mixture of gasoline, ethyl and methyl alcohol and water. It was planned to use liquid oxygen as an oxidizing agent. Compressed nitrogen from a separate cylinder was used to displace the fluids into the engine.
In preparation for the construction of future mail rocket planes, F. Kessler and his colleagues assembled and tested several prototype engines of their design. The tests of three ended with mixed results. The products provided the necessary thrust, but often exploded after some time of work. The designer considered that the cause of the accidents was not technical miscalculations, but someone's deliberate sabotage.
Preparing for the flight: checking the fuel tanks. Photo by Popular Mechanics Magazine
The technologies of the mid-thirties did not allow equipping the mail rocket plane with any control systems. Nevertheless, the inventors have repeatedly mentioned that further versions of such a product will definitely receive flight controls. Moreover, the desired flight performance could only be obtained through radio control using the appropriate equipment.
The complete rocket plane had a length of about 2 m with a similar wing span. The mass was determined at the level of 100 pounds - 45, 4 kg. It was assumed that he would develop a speed of several hundred kilometers per hour. The range was supposed to reach several miles so far. With the development of the engine and fuel system, the possibility of a sharp increase in flight performance was not excluded. The payload of the product was supposed to consist of several kilograms of correspondence placed in the head compartment.
It was assumed that further development of the project would yield very impressive results. The speed of the improved rocket plane could reach 500 miles per hour. The range is hundreds or thousands of miles. However, this required more powerful engines and a corresponding airframe design.
The designers are working with the engine. Photo by Popular Mechanics Magazine
The project of Kessler and his colleagues involved the use of two ways of starting. In the first case, the rocket plane had to take off using a separate launcher, for the development and assembly of which Marin Brothers from Greenwood Lake was involved in the project. In the second version, the simplest ski chassis was used, designed to provide independent acceleration of the aircraft and take off from a flat surface.
The launcher for the mail rocket plane was a truss made of many metal profiles, on which two inclined rails were located. A trolley with a launched aircraft was supposed to move along them. The installation had its own means of additional overclocking of the product. A cable was attached to the cart, thrown over a pulley in the front of the unit. A load was suspended from it. When the lock was opened, the load went to the ground, pulling a cart with a rocket plane behind it.
In 1935, already during the preparation of the technical project, the developers of the rocket plane proposed their invention to the US Post Office. Interest in the project was limited. For example, Charles Fellers, the head of the airmail department, paid attention to the project, but was not very impressed. Apparently, he was interested in more realistic projects using only available and developed technologies.
Final preparations for the launch of Gloria-1. Shot from newsreel
However, even without the support of official structures, the team of enthusiasts was able to complete the design and prepare several mail missiles for future tests and demonstration launches. In addition, F. W. Kessler, J. G. Schleich and W. Lake prepared special envelopes and stamps that could be placed on board the rocket plane. By collecting letters for rocket shipment, it was planned to cover at least part of the project costs.
The envelopes for the future launch had a special design. In the upper left corner was a rocket-powered plane in flight. Next to the drawing was the inscription "Via first american rocket airplane flight" - "Sent in flight of the first American rocket plane." There were stamps on the envelopes. They depicted a flying plane in red paint; there was a corresponding signature on the frame.
At the very beginning of 1936, rocket mail enthusiasts began collecting mail, which was soon to become the payload of a rocket plane. The announcement caught the attention of the public, and the team of inventors easily collected several thousand letters that could be sent in two "flights" of a rocket. The collection was completed in early February - a few days before the expected launch date.
Willie Leigh starts the engine. Shot from newsreel
Lake Greenwood, on the banks of which the city of the same name stood, was chosen as a site for test launches. The lake was covered with a half-meter layer of ice, which made it the most convenient testing ground. Two rocket launches in different configurations are scheduled for February 9; the launch site was designated a site on the shore of the lake. On the eve, a part of the necessary systems and units was delivered there.
However, the plans had to be adjusted. Almost on the night before the starts, a snowstorm hit the town, as a result of which the launch pad and the roads to it were skidded. J. Schleich had to hire workers with special equipment to clear the entrances and the site. It took several days to prepare for the new launch, but this time it was not without surprises. On February 22nd it started snowing again, although it didn't take long to clean up again.
On the day of the new launch attempt, February 23, 1936, more than a thousand people gathered on the shores of Lake Greenwood. Most of the spectators were local residents. In addition, several buses with tourists from other cities arrived at the "training ground". The flights were supposed to take place over a frozen lake, and people were on the shore - it was assumed that this would make it possible to do without any trouble. Almost at the last moment before the launch of the first rocket plane, the organizers of the event notified the police. The officers considered that the demonstration of the new technology would not be dangerous for people.
The second launch of the rocket plane: the product flew several meters, sat down on the bottom and went on the ice. Shot from newsreel
The first launch of the mail rocket plane was planned to be performed using a launcher. This rocket plane received its own name Gloria I - part of the daughter of J. Schleich. The product was filled and loaded with mail - several bags with 6127 letters were placed in its head compartment. Then it was installed on the accelerating trolley. The launcher was pointed towards the lake. Immediately before the launch, everyone moved away from the rocket to a safe distance. Only Willie Leigh, in a protective suit, remained with her. He had to bring the torch to the engine and make the ignition.
The fuel mixture ignited successfully and produced a solid torch. However, then the plume of fire diminished. At that moment, the cargo lock was opened, and the rocket-plane cart went forward. While the cart was accelerating the product, the engine simply turned off. The launcher was able to throw the rocket plane forward, but by this time it had turned into a glider. The aircraft flew only a few meters and fell into the snow. Fortunately, the product and its load were not affected.
Gloria-1 was returned to the launch position, refueled and prepared for a new flight. This time the engine started up normally and was even able to send the plane flying. However, too large an elevation angle of the launcher led to the fact that the rocket plane quickly gained a height of several meters and then lost speed. However, the stall did not happen. The rocket plane parachuted onto the ice, fell on the bottom and even traveled a short distance on it before being caught and stopped.
A special envelope for letters on board the Kessler-Schleich-Lei rocket planes. Photo Hipstamp.com
Immediately after two failures, the Gloria II rocket plane began to be prepared for the flight. It differed from the first one by the presence of the simplest ski chassis: it had to carry out a horizontal takeoff. After ignition, the product began to take off and even successfully took off. However, during the climb, the left plane "formed" at the plane. The whole right half-wing brought it into a roll, and after a few seconds the aircraft fell, receiving significant damage. The study of the wreckage showed that the cause of the accident was the insufficient strength of the wing structure. The light but fragile frame of the left wing could not withstand the air pressure and broke.
The payload of the first rocket plane did not suffer during the fall. Of course, the bags with correspondence were pretty crumpled, but their contents were in satisfactory condition. Immediately after the test launches, the letters were delivered to the nearest branch, from where they went to their addressees. Envelopes from the "first American rocket plane" quickly acquired collectible value and entered philatelic circulation. This was not even prevented by the fact that the stamps on the envelopes were not official.
Unfortunately, the two launches on February 23, 1936 were not only the first, but also the last in the history of the Kessler, Schleich and Lei project. Rocket planes Gloria I and Gloria II, undoubtedly, showed the capabilities of unusual technology for the transportation of mail, but at the same time demonstrated all its problems associated with the lack of technology development. To effectively solve its problems, the post rocket plane needed a more powerful and reliable engine, an increased fuel supply, control systems, etc. It was obvious that in the mid-thirties no one could make a cargo rocket plane with the desired characteristics and capabilities.
As far as is known, all participants in the bold project in the future showed interest in missile transport systems and even made a certain contribution to the development of technology. However, they did not return exactly to the idea of rocket mail. Further work in this direction in the United States was now carried out by other enthusiasts. It is noteworthy that many enterprising inventors began to develop their projects, inspired by the works of F. U. Kessler. Already in 1936, flights of new mail rockets, created by other designers, began. The first launch of a new product of this kind took place just a few months after the unsuccessful tests of two Glorias.
