To Mars in 70 days. Fantasy or reality?

After several months of rumors and gossip, NASA still released the results of a long-awaited study of the controversial EmDrive propulsion system. The work has recently been published.in the Journal of Propulsion and Power, where all work is peer-reviewed, owned by the American Institute of Aeronautics and Astronautics. If the electromagnetic technology turns out to be reliable, it can radically change the way people move in space, and open up the opportunity to fly to Mars in just 70 days. But the idea has enough skeptics who are confident that the engine is not a fact, but science fiction. Critics like to point out a violation by the engine of one of the fundamental laws of physics: for every action there is an equal and oppositely directed reaction. While the scientific world is buzzing with excitement, the magazine UConn Today has recruited technical science professors Bryce Cassenty [ Brice Cassenti ], an expert on complex motor systems, to help us understand what is happening.

Q: What is the EmDrive propulsion system and what distinguishes it from the rest?

A: EmDrive uses electromagnetic waves (used, for example, in radar installations) to create thrust - which, in general, is the first requirement for any rocket engine. The engine consists of a truncated conical copper shell with a plastic (polyethylene) disc covering the narrow end of the truncated cone. An electromagnetic wave is created inside the copper shell in the same way that waves are generated in a microwave oven. A unique system in that the device does not use traditional jet fuel. Instead, to put it simply, electromagnetic waves jump inside a cone in such a way that, according to some people, lead to a thrust. In the tests, NASA reported a 1.2 mN / kWh load that appeared in a vacuum, which is a very small, but noticeable, movement.

Q: What reinforces all this skepticism, and what do you think about this?

A: Although the EmDrive seems to produce cravings in these tests, no outgoing mass or particles appear during the tests. This is a violation of Newton's third law, which says that for every action there is an equal and oppositely directed reaction. Action and reaction - a direct result of the conservation of momentum. Violation of such a basic law as the law of conservation of momentum will reject most of the foundations of all known physics. Therefore, many scientists and engineers believe that the measured thrust is due to experimental error. To this is added the fact that people who believe in the correctness of the result have no plausible physical explanation of the phenomenon. For example, electrical currents heat up engine components, expanding in experiments, and this movement can be taken as a driving force. It is very difficult to eliminate such effects, although the authors of the article attempted to eliminate not only these temperature effects, but also many other possible sources of experimental errors. It is extremely difficult to be sure that all possible sources of errors are eliminated. The only method is to create a hypothesis or theory

Q: The fact that a NASA study has passed peer review is advertised as an important step. What does the approval of experts in a study that is in the process of development really mean?

A: The expert assessment is important because it means that the work was checked by other experts, and the results were professional enough and important to share with the public. But this does not mean that the experts considered the results correct. The expert who assessed this work, with whom I spoke before publishing it in the journal, does not consider that it points to some new physics. But he considered that the results were rather confusing for its publication.

Q: If EmDrive works, does this mean that Newton was wrong, and there are mysterious aspects of physics that are not clear to us?

A: If the results are correct, they definitely indicate a new physics. It has already been shown that Newton's laws are not applicable to high velocities (where the special theory of relativity works), in strong gravitational fields and with very small molecules. But Newton is mostly right. Of course, many aspects of physics are incomprehensible to us. Some of them are so mysterious that we don’t even know where to start!

Q: Everyone is excited about testing EmDrive in space as the next step. What are the advantages of testing a device in space than on Earth?

A: If the EmDrive is tested in space, then the acceleration can be measured directly, which eliminates all the confusion associated with the measurement of forces. There will be an ideal vacuum in space, the device will not need to be placed in a vacuum chamber, there will be weightlessness, which will eliminate the need for supporting equipment (current tests rely on a balancer to measure forces). But space missions are expensive - launching one kilogram of weight into orbit costs $ 10,000. Perhaps it would be better to try first to experimentally find the cause of the appearance of thrust, and only when the cost of ground-based experiments begins to approach the cost of the orbital mission, will the experiment need to be conducted in space.

Q: Would you like to add more about EmDrive for a better understanding?

A: No, but in my professional career I have seen several such amazing experiments or theoretical results appearing in literature subject to expert judgment. And so far only the existence of black holes has turned out to be a reality. So, in my experience, the possibility that this topic will withstand the subsequent analysis and experiments is small. But not zero.