OTRAG
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OTRAG (German: Orbital Transport und Raketen AG, or Orbital Transport and Rockets, Inc.), was a German company which planned in the late 1970s and early 1980s to develop an alternative propulsion system for rockets. OTRAG was the first commercial developer and producer of space launch vehicles. The OTRAG Rocket represents an inexpensive alternative to existing launch systems through mass-production of innovative Common Rocket Propulsion Units (CRPU).
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[edit] History
OTRAG was founded in 1975 by the German aerospace engineer Lutz Kayser. Its goal was to develop, produce, and operate a radically different, low cost satellite launch vehicle.
As developed, the OTRAG rocket represents an inexpensive alternative to the European rocket Ariane and the NASA space shuttle. Kayser and a private consortium of six hundred European investors financed the development and production of the OTRAG satellite launch vehicle. Dr.Ing Kurt Debus served as Chairman of the Board of OTRAG after his retirement as director of NASA's Kennedy Space Center, and Dr. Wernher von Braun served as scientific adviser to Kayser.
In the face of doubts by Debus and von Braun, Kayser chose in 1975 to set up testing and launch facilities at Shaba, Zaire (the Congo. Debus and von Braun were concerned about the possibility of Zairian acquisition of missile technology from the facilities. Kayser decided to proceed despite their opposition, and testing began at the site in 1977.
Political pressure to halt the company's operations mounted quickly. France and the Soviet Union were historically opposed to German long-distance rocket development, and pressured the Congolese government into closing down the development facility in 1979. Immediately afterwards, Presidents Giscard d'Estaing of France and Leonid Brezhnev of the Soviet Union convinced the West German government to cancel the OTRAG project and close down its German operations. In 1980, OTRAG moved its production and testing facilities to a desert site in Libya. A series of successful tests were conducted at this site beginning in 1981.
[edit] Technique
OTRAG was a design quite different from the conventional multi-stage rockets. The OTRAG design consisted of parallel stages assembled from parallel tanktubes with flat bulkheads. The rockets were designed to carry loads up to two tons, the weight of a then usual communications satellite, into a geostationary orbit. It was planned to later increase the capacity to ten tons or more using multiple identical modules.
The rocket was to consist of individual pipes, each 27 cm in diameter and six meters long. Four of these pipes would be installed one above the other resulting in a 24 meter long fuel and oxidizer tank with a rocket engine at the lower end. The fuel was intended to be kerosene and nitric acid. Ignition was provided by a small quantity of furfuryl alcohol injected before the fuel, which ignites hypergolically (immediately and energetically) upon contact with the nitric acid. To simplify the design, pumps were not used to move the fuel to the engines, instead the fuel tanks were only 66% filled, with compressed air in the remaining space to press propellants into the ablatively cooled combustion chamber. Thrust control is by partially closing the electromechanical propellant valves. Pitch and yaw control can thus be achieved by differential throttling. In principle this is extremely reliable and cheap in mass production.
The modular design results in a huge cost reduction because of the law of mass production. The CRPU-based satellite launching rocket was estimated to cost approximately one tenth of conventional designs. Automated production processes for all components would reduced labor cost from 80% to 20% and remove the justification for reusability of spent stages.
[edit] Controversies and future outlook
Only a few political controversies are known concerning OTRAG because of concerns of neighbors of Zaire and Libya about the dual use potential of rockets. A full orbital launch vehicle was never assembled. Modules were flight tested in Zaire and Libya. 6000 static rocket engine tests and 16 single stage qualification tests were made to prove the concept as feasible.
The German minister of foreign affairs at that time, Hans Dietrich Genscher, is said to have finally stopped the project under pressure from France and the Soviet Union, and West Germany joined the co-financed "European rocket" Ariane project, which made the OTRAG project unnecessary and eliminated political entanglements of a still divided Germany in the early 1980s.
No government was interested at that time in reducing costs, and commercial satellite operators had no choice but to accept the high launch cost.
It is estimated that this technology would achieve transport cost into Low Earth orbit of approximately 1000$/lb payload in contrast to present cost greater than 10000$/lb.
It is estimated that the total cost for transport of lunar and martian exploration and station construction material can be reduced by approximately US$ 30 Billion assuming a mass requirement in LEO of 3,000 tons until 2030.
It remains to be seen if Lutz Kayser can convince private investors that now the time is ripe to complete this venture. The necessary US$ 100 Million for the inventions and technological breakthroughs in rocket technology have been paid for in the last 30 years and are a solid foundation to proceed to CRPU mass production and clustered flights to qualify stage separation and orbital insertion for a 3-stage launcher.
It is presently not known if and with whom Lutz Kayser is negotiating joint ventures; however the recent NASA COTS announcement stipulates a 50% US National ownership in vendor companies like von Braun Debus Kayser Rocket Science LLC, DE (BDKRS). This would force Lutz Kayser to sell at least 50% of his shares to Americans, since he is a German citizen.
[edit] See also
[edit] External links
- http://www.bernd-leitenberger.de/otrag.shtml very explantive article about the OTRAG history (de)
- http://www.astronautix.com/lvs/otrag.htm (en)