Science fiction revisited: Ramjet propulsion

In science fiction tales about contact with extraterrestrial civilisations, there’s a downside: What type of propulsion system might make it attainable to bridge the big distances between the celebrities? It can’t be accomplished with peculiar rockets like these used to journey to the moon or Mars. Many roughly speculative concepts about this have been put ahead—considered one of them is the “Bussard collector” or “Ramjet propulsion”. It includes capturing protons in interstellar space after which utilizing them for a nuclear fusion reactor.

Peter Schattschneider, physicist and science fiction creator, has now analyzed this idea in additional element collectively along with his colleague Albert Jackson from the USA. The result’s sadly disappointing for followers of interstellar travel: it can’t work the best way Robert Bussard, the inventor of this propulsion system, thought it up in 1960. The evaluation has now been revealed within the scientific journal Acta Astronautica.

The hydrogen-collecting machine

“The idea is definitely worth investigating,” says Prof. Peter Schattschneider. “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.” In 1960, Robert Bussard revealed a scientific paper about this. Nine years later, such a magnetic field was described theoretically for the primary time. “Since then, the idea has not only excited science fiction fans, but has also generated a great deal of interest in the technical and scientific astronautics community,” says Peter Schattschneider.

Peter Schattschneider and Albert Jackson now took a more in-depth take a look at the equations, half a century later. Software developed at TU Wien as a part of a analysis venture for calculating electromagnetic fields in electron microscopy unexpectedly turned out to be extraordinarily useful: the physicists had been in a position to make use of it to point out that the fundamental precept of magnetic particle trapping truly works. Particles might be collected within the proposed magnetic field and guided right into a fusion reactor. In this fashion, appreciable acceleration might be achieved—as much as relativistic speeds.

Huge dimensions

However, when the dimensions of the magnetic funnel is calculated, hopes of a go to to our galactic neighbors shortly fade. To obtain a thrust of 10 million newtons—equal to twice the primary propulsion of the Space Shuttle—the funnel must have a diameter of just about 4000 kilometers. A technically superior civilisation would possibly have the ability to construct one thing like that, however the actual downside is the required size of the magnetic fields: The funnel must be about 150 million kilometers lengthy—that is the gap between the sun and the earth.

So after half a century of hope for interstellar journey within the distant future, it’s now obvious that the ramjet drive, whereas an fascinating concept, will stay merely a part of science fiction. If we need to go to our cosmic neighbors one day, we should give you one thing else.