Have you heard of rocket planes? No, not the planes we make with paper in our classrooms, letting them fly around during a free hour. Rocket planes or rocket-powered planes are aircraft propelled by rockets, sometimes in addition to jet engines.
These planes are capable of achieving much higher speeds than similarly sized jet aircraft and are also suitable for flying in very high altitudes. Propulsion through rocket engines implies that these aircraft can also achieve shorter take-offs and much higher acceleration.
The first of these aircraft that was used in a public demonstration came about late in the 1920s. It turned out to be a reality, thanks to the work done by three men, who brought in their individual skill sets together for this project.
Meet Valier, Opel & Sander
The first among these was Max Valier, an Austrian rocketry pioneer. Valier worked tirelessly to popularise rocketry and wrote many popular articles and books that brought this technology closer to the layperson. He was also among the earliest to experiment with rocket-powered vehicles and dreamt of rocket-powered flights that will not only cut down the flying time between cities, but also eventually take human beings into space.
Fritz von Opel, a German engineer and industrialist, was the second person. Grandson of Adam Opel, the founder of the Opel company that now manufactures automobiles, Fritz was a racing driver and entrepreneur with an eye for detail, both technically and organisationally. German engineer Friedrich Wilhelm Sander completed the trio. A manufacturer and expert in pyrotechnics, Sander owned a company, which he expanded to produce rockets.
Together for the project
While Valier was drawn towards rocketry as early as 1924 after reading physicist Hermann Oberth’s research on the idea of rockets carrying humans to space, Opel was sucked into it after meeting Valier in 1927. The fact that Opel decided to get actively involved in the rocket research project also meant that he brought with him his financial clout. Believing that the Opel brand would have a positive impact through such an involvement, he next brought Sander into the project. As Sander’s company made solid fuel signal rockets, Opel was hoping for faster implementation of the rocket motor through this move.
As early as March 1928, the trio of Valier, Sander and Opel started seeing the fruits of their labour. Rocket-propelled prototypes of automobiles were launched behind closed doors, and by April, the automobile RAK 1 was test-driven. Opel decided to drive the RAK 2 automobile himself and on May 23, 1928, he fired the 24 solid fuel rockets fitted to his futuristic car and pushed it to a maximum speed of 238 km/hour! The feat, performed in front of nearly 3,000 people including celebrities, earned him the nickname “Rocket Fritz”.
From cars to aircraft
Spurred on by their success, the trio turned their focus towards aviation. Despite setbacks, including the explosion of one of their test flights, they carried on and were ready for their demonstration next year. On September 30, 1929, Opel piloted the RAK 1 (sometimes referred to as RAK 3 to distinguish it from the automobile), the first such public rocket-powered flight, in front of a large crowd.
Opel flew at an altitude averaging about 50 feet and covered nearly two km in less than 100 seconds. Even though the plane was wrecked during landing, Opel was able to escape unhurt and wrote that it was “marvelous to fly like this” in an article in The New York Times after the flight. The Great Depression that came about at that time, however, put an end to these rocket experiments, pushing Opel’s company to focus instead on vehicle development.
In the decades that followed, rocket-powered aircraft were initially deployed in warfare and a number of models were built during World War II. Rocket planes were the first to break the speed of sound in level flight and they continue to be built for experimental usage, owing to the fact that there are practical difficulties while operating rockets.
Picture Credit : Google