Yes, OTRAG Influenced the EcoRocket Heavy Design — AMi, Part XXI
In the 80’s, during the Communist age in Romania, there were very few technology-related magazines available to the public. They were literally “devoured” by the local tech heads. Modelism (‘model-making’) was one of them. Its focused on technical drawings, together with specifications and the history of various vehicles like aircraft, trains, ships and rockets, for passionate people to make scaled-down models of them. In one of the Modelism issues, a very interesting vehicle was presented. It was OTRAG, a German rocket developed at the end of the 70s and the beginning of the 80s. This project pre-dated today’s private spaceflight initiatives by almost 50 years. Back then, the space launch industry was dominated by government programs and the OTRAG initiative was a clear exception. But the philosophy behind their project was outstanding.
The Orbital Transport und Raketen, AG (OTRAG) was founded in 1975 by Lutz Kayser and had Dr. Kurt H. Debus and Dr. Werner Von Braun as advisers. They decided to make space launches really affordable, and they thought that they had the solution for that. They focused on development and cost-effective launches rather than on rocket performance. For that, they used off-the-shelf components as much as possible, and simple fabrication solutions. They used non-cryogenic propellants, kerosene as fuel, and nitric acid and di-nitrogen tetroxide as oxidiser. Those were easier to manipulate and store. Their engines were built from graphite, did not require any cooling, and only had one valve for each propellant. The propellant tanks were built from thin, stainless steel tubing used in the oil industry. Instead of ellipsoidal or spherical caps, they used flat bolted ones, as their tanks had a diameter of only 27 cm.
Their thinking was simple: instead of building curved caps that are indeed lighter, through a more complex and expensive production method, better use a heavier part, that will not have a significant weight penalty, but it will lead to an important cost reduction. The tanks and the engines made up a single Common Rocket Propulsion Unit (CRPU), with a thrust of 2,750 kgf. These CRPUs were clustered together to form rockets able to lift tons of payload to orbit. The engines were ungimbaled, and the vehicle’s steering was achieved by throttling specific engines from the CRPU cluster up and down.
OTRAG believed that a rocket built from multiple identical segments could be mass produced by a large number of people who aren’t necessarily highly qualified, in the same way that automobiles are produced, through a repetitive process. They attempted to build the Fords of rockets instead of a Rolls Royce, which all present-day rockets still are. There are no mass-market models available, only luxury ones. It is true that rockets like Soyuz came close to that with its low fabrication and launch cost, but even that doesn’t come close to what OTRAG attempted to do.
I need to admit that when I started to design and build rockets, in 1998, 15 years after that article in Modelism, I thought about OTRAG, and I decided to implement their philosophy in ARCA’s first rocket, Demonstrator 1. It never flew, but it was the basis for the successful Demonstrator 2B that was launched in 2004 from the Cape Midia Air Force Base, on the Black Sea shore. These two rockets were built in a backyard by only three people with a microscopic budget in the range of $30,000. After that, I departed from that successful design and focused on much more complex designs that weren’t that successful. Then, for the EcoRocket, 20 years later, after having tried various other options to create the ideal cost-effective rocket, I returned to the basics with the EcoRocket and then EcoRocket Heavy designs. The OTRAG program didn’t provide just inspiration for the design approach, but it also helped me learn about political influences, what mistakes they did, and what is there to learn from it.
With the AMi Exploration Program, we are much where OTRAG was at the end of the 70s. They were facing politically driven criticism from the scientific community, and also strong political pressure from the USSR, USA and Europe. The criticism and pressure were related to fact that OTRAG was a threat to the status-quo of the space launch industry. Obviously, OTRAG didn’t target specific people, organisations or companies, but their very existence was perceived as a threat and was met with harsh opposition and pressure, as their detractors thought that the OTRAG rocket was a threat to the then-new Ariane program.
OTRAG operated in Germany, and launched their first test rockets from Zaire. After these successes, USSR and France published articles claiming that the OTRAG technology is an undercover program to produce ballistic missiles for third-world countries. This had a severe impact on the company’s reputation and they operated in a difficult, propaganda-led environment. Political pressure from the USSR and France forced the company out of Zaire in 1979. In 1980, it moved to Libya where it performed more launches. Gaddafi planed to develop military missiles and seized their equipment, but he failed in his plans without their technical support and know-how.
OTRAG then moved to Sweden, where they continued to test-launch their vehicle. In 1987 the company ceased its operations, and Lutz Kayser retired to live on a Pacific island, where he died in 2017.
The OTRAG design philosophy influenced the EcoRocket Heavy design.
We had constraints related to the creation of a huge infrastructure able to handle and assembly huge single structures. This was the main reason for which we opted, similarly to the OTRAG rocket, for multiple Propulsion Modules for the EcoRocket Heavy. These are easier to fabricate and integrate to form a larger structure.
OTRAG undoubtedly made mistakes, some of which were related to their founder Lutz Kayser and his lifestyle. He lived an opulent life supported by company money and he was often missing from key fabrication and test activities. This surely had an impact on the technical outcomes of their work. In my opinion, regardless of what every day brings, a CEO’s main focus in the first few years at least, should be product development.
Another major mistake was OTRAG’s involvement with countries like Zaire and Libya, known for their dictatorships. They did not have too many launching options at the time, but the association with those regimes definitely helped their detractors and prompted strong reactions from the USSR and France.
Despite all these, Lutz Kayser was a revolutionary aerospace engineer, well ahead of his time. His work influenced us and other companies, and we are pretty sure it will continue to be influential. He and OTRAG left their mark on space flight, and they will never be forgotten.
The AMi development program is financed through ARCA’s AMiE Crypto.
