Opel Rocket Car

Fritz von Opel sponsored early tests of rocket-powered automobiles and aircraft, popularizing the idea of rocket propulsion in Germany.

Manufacturer: Opel.

1928 March 15 - Launch Vehicle: Opel.

• First rocket car Nation: Germany. Max Valier campaigned to get automobile magnate Fritz von Opel interested in rocket-powered automobiles. Valier proposed to use different combinations of compressed black powder rockets manufactured by Friedrich Wilhelm Sander of Wesermuende. Sander's rockets were 80 cm long, 12.5 cm in diameter, and could came in two versions. The centre-bore rockets provided 180 kgf for 3 seconds, while the end-burners provided 20 kgf for 30 seconds. Valier proposed to use combinations of these motors to first boost an automobile to high speed with the high-thrust rockets, then use low-thrust units to maintain velocity. This had no practical application but would demonstrate the potential of rockets to the German public, at the same time giving Opel publicity. The first secret test, at Ruesselsheim, used a one high thrust and one low thrust motor in a small stock Opel. The results were unimpressive - the vehicle went only 140 m in 35 seconds.References: 47.

• Opel Rak Nation: Germany. After two tests the day before, which showed that a good fraction of Brander's rockets would either fail to ignite or explode, Valier made the first official rocket car run for the press. Of 12 rockets attached to the 'Rak' vehicle (a motor car stripped of engine and brakes), five failed to function, but the vehicle reached 110 kph and the press was mightily impressed. Opel received an unexpected amount of free publicity and funded Valier in further rocket car development.References: 47.

• Opel Rak II Nation: Germany. Fritz von Opel personally drives rocket-car Opel Rak II, equipped with 24 Brander powder rockets, to 200 kph at Berlin. The same day Oberth is debating the German scientific establishment, trying to overturn their belief that space flight using liquid rockets is theoretically impossible. The VfR regard Valier's experiments with Opel as publicity stunts, threatening the credibility of their society.References: 47.

• First manned rocket-powered aircraft flight. Nation: Germany. Flight Crew: Stamer. A rocket-boosted glider is flown by Friedrich Stamer from the Rhoen Mountains in Western Germany. The development was funded by Opel, the canard-layout glider designed by Hans Lippisch, and the powder rockets developed by Sander. As in the Opel ground vehicles, a boost rocket (360 kgf for 3 seconds) was to accelerate the glider down the launch ramp. A sustainer rocket (20 kgf for 30 seconds) would keep the aircraft in flight. It was hoped to develop a method of launching gliders that would allow the pilot to get airborne without assistance - that did not require a tow aircraft or the eight-man crew needed to pull back the rubber band on existing rail launchers. Tests with smaller motors in models showed the high-thrust motors were too powerful, so the full-scale tests used a standard rubber-band rail launcher with only the low thrust motors installed. After two attempted flights, Stamer finally made a successful flight, firing two 20 kgf motors one after the other. The glider flew about 1.5 km in 70 seconds. On the second flight the first motor exploded, setting the aircraft on fire. Stamer landed successfully but further attempts were abandoned.References: 47.

• Opel Rak III Nation: Germany. The third Opel rocket-car is mounted on railroad tracks near Celle. The first run, with 10 rockets, reached 290 kph. A second run, with 24 rockets, jumped the tracks and demolished the vehicle. References: 47.

• Opel Rak IV Nation: Germany. The fourth Opel rocket-car is destroyed when one motor explodes, setting off all off the other motors simultaneously. The car jumps off the tracks at the start. Rail authorities prohibit further experiments and Opel Rak V never runs. References: 47.

• Opel Sander Rak 1 flies. Nation: Germany. Flight Crew: Opel. Opel sponsored resumption of tests of rocket-boosted gliders near Frankfurt-am-Main, Germany. These involved a design by Lippisch, boosted by 16 powder rockets of 23 kgf each. With Opel at the controls, the glider successfully launched itself from a 20-m long rail launcher, and he flew the aircraft for ten minutes. However the landing went badly - the design had a landing speed of 160 kph, and with a total weight of 270 kg, a high wing loading. Opel survived but the glider had to be written off. This was Opel's last involvement with rocketry. General Motors, the majority owner of the Opel company, prohibited further rocketry work after the stock market crash. Fritz von Opel left the country and moved to Switzerland.References: 47.

• Emme, Eugene M, Aeronautics and Astronautics: An American Chronology of Science and Technology in the Exploration of Space 1915-1960, NASA, 1961. Accessed at: http://www.hq.nasa.gov/office/pao/History/timeline.html.

• Ley, Willy, Rockets Missiles and Men in Space, Viking Press, New York, 1968. ISBN: 0670602264. Willy Ley was one of the great science writers and promoters of spaceflight in the 1950's. This book covers basic concepts and the history of rocketry up to the early 1960's. More at amazon.com...