In science fiction, we read stories about contact with extraterrestrial civilizations. But the question is what kind of propulsion system will make it possible to bridge the enormous distances between the stars. It possibly cannot be done with ordinary rockets like those we use to travel moon or Mars. Scientists put forward many more or less speculative ideas about this and on of them is “Bussard collector” or “Ramjet propulsion”. This can capture protons in interstellar space and then use those protons for a nuclear fusion reactor.
Physicist and science fiction author, Peter Schattschneider, has analyzed this concept in more detail with the help of his colleague Albert Jackson. But the result may disappoint fans of interstellar travel, as it does not work as the inventor of this propulsion system, Robert Bussard thought it in 1960. The analysis of the research has been published in the scientific journal Acta Astronautica.
The machine that collects hydrogen
According to Prof. Peter Schattschneider, the idea was worth investigating. Schattschneider said, “In interstellar space there is highly diluted gas, mainly hydrogen—about one atom per cubic centimeter. If you were to collect the hydrogen in front of the spacecraft, like in a magnetic funnel, with the help of huge magnetic fields, you could use it to run a fusion reactor and accelerate the spacecraft.”
Robert Bussard has published a scientific paper about this in 1960. In 1969, for the first time such a magnetic field was described theoretically. From that time, the idea has excited science fiction fans. It also generated a great deal of interest in the technical and as well as scientific astronautics community.
Schattschneider and Jackson took a closer look at the equations. They have used software developed at TU Wien for calculating electromagnetic fields in electron microscopy. This calculation was extremely helpful. The scientists used it to show that the basic principle of magnetic particle trapping is working. Particles can be collected in the proposed magnetic field and can also be guided into a fusion reactor. Thus, we can achieve considerable acceleration, up to relativistic speeds.
Big dimensions
When the size of the magnetic funnel is calculated, hopes to visit our galactic neighbors fades with it. If we want to achieve a thrust of 10 million newtons, the funnel needs to have the diameter of 4000 kilometers. A technically advanced civilization can build that, but the real problem is the required length of the magnetic fields. The funnel needs to be 150 million kilometers long which is the distance between the sun and the earth.
So, we can say that in conclusion that ramjet drive will remain a part of science fiction for now.
