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Propulsion on an Interstellar Scale – the Quantum Vacuum Plasma Thruster




You might think, “Hey, the fastest moving man-made object, the Voyager 1 spacecraft, is cruising through space at 57,600 km/h.  That’s pretty fast.”

But when you consider that the distance between our sun and our closest stellar neighbor, Alpha Centauri A (ACa), is nearly 38 trillion kilometers, Voyager’s blistering pace is more akin to a crawl.  If Voyager 1 were to continue at its current pace it would take about 75 millennia to get to ACa.  Now that astronomers are beginning to find extra-solar planetary systems NASA is looking into advanced propulsion techniques to “enable human exploration of the solar system over the next 50 years, and… interstellar spaceflight by the end of the century.”

So what type of propulsion system could make exploring nearest stars a reality?

NASA believes that a Quantum Vacuum Plasma Thruster (QVPT) might be the breakthrough system they need.

Before we dive into what exactly a QVPT is we first have to know a little about Quantum Mechanics, specifically Quantum Vaccuums. We all know that nature abhors a vacuum, and this statement is true on both the macro and micro level. In quantum mechanics a vacuum is filled with electromagnetic waves that come into existence, and then immediately disappear. While these electromagnetic waves are extraordinarily small, they do have many measurable effects. One of these effects is that as the electromagnetic waves appear and disappear they leave behind a measurable momentum.

So the question is, can NASA scientists transform this momentum to create propulsion?  The answer, Maybe!

NASA scientists think that using the Casimir Force might be key in creating an abundance of electromagnetic fluctuation that could result in propulsion.

According to NASA, “The Casimir force is a QV phenomenon such that two flat plates placed in close proximity in the vacuum preclude the appearance of particles, whose wavelength is larger than the separation gap, and the resultant negative pressure between the two surfaces is more negative than the pressure outside the two surfaces, hence they experience an attractive force”

This attractive force could be used to create a pool of electromagnetic particles whose momentum could be used to drive a spacecraft.

But what does all of this Quantum Mechanics business have to do with our QVTP? Well, the pool of electromagnetic particles that’s been created by the Casimir force is going to be the fuel for the QVPT. That means that a QVPT doesn’t have to carry a fuel source to propel itself onward, it can generate propulsion through the manipulation of quantum electro dynamics.

There’s still a lot of fundamental science that needs to be done to make this type of engine a reality, but NASA believes that the only limit to the potential of this type of propulsion system is the power supply that creates the thruster’s specific impulses. NASA does admit “The magnitude of thrust arising from using the dynamic Casimir force derived numerous times in the literature has been shown to be very small in comparison with conventional propulsion systems, but has been clearly shown to be theoretically possible.”

In fact, NASA’s initial projections for a QVPT estimate that if a 100MW, 200mT (QVPT) could be engineered, the timeframe for transit between the Earth and Neptune would be just over 100 days. But ACa would still be a long way away.  At that pace it would take 2,364 years.  That’s long enough for a Planet of the Apes scenario.