Impossible Space Drives and Interplanetary Transport Networks

By Max Maxfield |

To date, there is no theoretical consensus as to how a resonant cavity can provide for the direct conversion of electrical energy to thrust without the need to expel any propellant.


I love just about anything to do with space. I really wish that I could travel around the universe on an Orville-class starship to visit far-flung star systems, walk on alien planets, and observe wondrous celestial phenomena.

I’m also constantly amazed by the weird and wonderful ideas that people come up with. Take the Interplanetary Transport Network (ITN), for example. When most people think about sending something like a space probe to another planet in our solar system (say, Saturn), they typically consider using a honking big rocket. The problem is that traditional rocket engines require a lot of fuel. One way around this — and to shorten the duration of the mission — is to fly our space probe close to another planet that’s on the way, like Jupiter, and to use a gravitational slingshot effect to accelerate the spacecraft and modify its path.

If you don’t mind how long it takes to reach the target destination, then the Interplanetary Transport Network provides an alternative mechanism. If you take two large bodies in space, like Earth and the moon, for example, then there are five locations called Lagrangian points, or Lagrange points, where a smaller object like a space probe can maintain its position relative to the two larger objects.

Where things really start to become interesting is when you combine chaos theory with three or more bodies, such as planets and other objects forming our solar system. In this case, we can map flight paths between the various Lagrange points, where we can visualize these paths as being tubes in space.

Stylized depiction of the Interplanetary Transport Network (Source: NASA)

Once we get our space probe to one of the Earth-moon Lagrange points, then — using the Interplanetary Transport Network — it would be possible to transport it almost anywhere in the solar system using very little energy. The downside to this approach is that it could take a long, long time to get there.

But that’s not what I wanted to talk to you about. This column was sparked by my running across developments in NASA’s futuristic EM Drive (also known as the EmDrive), which is based on an RF resonant cavity thruster

The problem here is that traditional rocket engines are reaction engines that obtain thrust by expelling mass in accordance with Newton’s third law, which can be summarized as, “For every action, there is an equal and opposite reaction.” Most of us think about rockets based on the use of liquid propellants or solid fuel, but even in the case of an ion drive, the engine creates thrust by accelerating and expelling ions.

By comparison, the EmDrive features a microwave cavity that produces thrust from an electromagnetic field inside the cavity. Originally hypothesized by British engineer Roger Shawyer in 2001, the EmDrive did not, at first, gain much traction. Many theoretical physicists say that the device is “impossible” because it appears to violate the laws of physics as they are currently understood.

To date, there is no theoretical consensus as to how a resonant cavity can provide for the direct conversion of electrical energy to thrust without the need to expel any propellant. This made it all the more interesting (or embarrassing, depending on your point of view) when NASA successfully tested an EmDrive in 2014.

One possibility is that the EmDrive is leveraging quantum effects, like using the fleeting electromagnetic waves and virtual particles that pop into and out of existence in the quantum vacuum. While this may sound a tad esoteric, let’s not forget that all sorts of weird and wonderful effects happen at the quantum level, including quantum entanglement and quantum teleportation.

On the one hand, I’m extremely proud of all that we (the human race) have discovered and accomplished. At the end of the day, however, I’m left thinking that we still understand very little compared with all the things there are to know. As usual, the Bard of Avon nailed it in Hamlet, when Hamlet says to Horatio, “There are more things in heaven and earth, Horatio, than are dreamt of in your philosophy.”

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  • by  PeterTraneus Anderson

    https://physicsfromtheedge.blogspot.com/  Mike McCulloch has been developing a theory of quantized intertia. One of its predictions is that the EM drive does work because the drive is pushing against the edge of the universe. The EM drive can be proven straightforwardly: Put one up in a satellite and use the EM drive to fly around the moon.

    • by  Max Maxfield

      @Traneus Rex: "...Mike McCulloch has been developing a theory of quantized intertia. One of its predictions is that the EM drive does work because the drive is pushing against the edge of the universe..."

      Interesting -- I just visited his site -- I like the fact that Mike's theory provides an alternative to Dark Matter (I never felt attracted to Dark Matter :-)

  • by  Max Maxfield

    @Traneus Rex: "...Mike McCulloch has been developing a theory of quantized intertia. One of its predictions is that the EM drive does work because the drive is pushing against the edge of the universe..."

    Interesting -- I just visited his site -- I like the fact that Mike's theory provides an alternative to Dark Matter (I never felt attracted to Dark Matter :-)

  • by  Rick Curl
    Max- I just started watching a TV series called "Salvation" about an asteroid that is on a collision course with the Earth.  The EM drive plays a key part in the plot.


    Might want to give it a look.  

    -Rick

    • by  Max Maxfield

      @Rick: "...I just started watching a TV series called "Salvation" about an asteroid that is on a collision course with the Earth.  The EM drive plays a key part in the plot..."

      Interesting -- I'll take a look at the pilot episode, but it might take me a couple of days.

    • by  Max Maxfield

      @Rick: "...I just started watching a TV series called "Salvation" about an asteroid that is on a collision course with the Earth.  The EM drive plays a key part in the plot..."

      I tried to find Salvation yesterday evening -- it's not on Neflix, nor on the iTunes Store -- what were you watching it on?

    • by  Max Maxfield

      @Rick: "...I just started watching a TV series called "Salvation" about an asteroid that is on a collision course with the Earth.  The EM drive plays a key part in the plot..."

      I watched the first/pilot episode this past weekend -- VERY EXCITING -- when I finish some of the other stuff I'm watching, I will come back to watch the rest of the series. Thanks for sharing :-)

  • by  Max Maxfield

    @Rick: "...I just started watching a TV series called "Salvation" about an asteroid that is on a collision course with the Earth.  The EM drive plays a key part in the plot..."

    Interesting -- I'll take a look at the pilot episode, but it might take me a couple of days.

  • by  Max Maxfield

    @Rick: "...I just started watching a TV series called "Salvation" about an asteroid that is on a collision course with the Earth.  The EM drive plays a key part in the plot..."

    I tried to find Salvation yesterday evening -- it's not on Neflix, nor on the iTunes Store -- what were you watching it on?

  • by  Max Maxfield

    @Rick: "...I just started watching a TV series called "Salvation" about an asteroid that is on a collision course with the Earth.  The EM drive plays a key part in the plot..."

    I watched the first/pilot episode this past weekend -- VERY EXCITING -- when I finish some of the other stuff I'm watching, I will come back to watch the rest of the series. Thanks for sharing :-)

  • by  Sean Ellis

    When a device claims to violate well established physical principles, then the burden of proof is necessarily very high.

    Although I am always open to good evidence, the pattern here is a common one and it raises a big red flag.

    We see initial claims of a large easily-measured effect, followed by failed or inconsistent replications and scaling back to smaller effect sizes as controls are tightened. This usually ends in a situation where the final loopholes or errors are eliminated leaving no actual effect to be demonstrated.

    While it would be wonderful to remove the tyranny of having to carry reaction mass, it would be long odds indeed to bet against the whole of the rest of physics.

  • by  Max Maxfield

    @Sean: "...While it would be wonderful to remove the tyranny of having to carry reaction mass, it would be long odds indeed to bet against the whole of the rest of physics..."

    Isn't that what they said to Einstein? LOL

    On the one hand I totally agree with you. My first reaction was "Perpetual Motion Machines" and "Cold Fusion" ... but there seems to be some interesting "stuff" happening in the Cold Fusion arena, and the more I read about the EM-Drive, the more I think "maybe, just maybe..."

  • by  Rick Curl

    @Max: "I tried to find Salvation yesterday evening -- it's not on Netflix, nor on the iTunes Store -- what were you watching it on?"

    I'm getting it on Amazon via my Roku. 

    Knowing the way you think, you'll pick up on a couple of glaring technical errors (I won't spoil it for you at the moment), but it's still very much worth watching.

    -Rick

    • by  Max Maxfield

      @Rick: "...I'm getting it on Amazon via my Roku..."

      Does that mean it's available on Amazon Prime?

      • by  Rick Curl
        Yep.  Eager to hear your opinion of the series.
  • by  Max Maxfield

    @Rick: "...I'm getting it on Amazon via my Roku..."

    Does that mean it's available on Amazon Prime?

    • by  Rick Curl
      Yep.  Eager to hear your opinion of the series.
  • by  Rick Curl
    Yep.  Eager to hear your opinion of the series.
  • by  Max Maxfield

    @Rick: "...Knowing the way you think, you'll pick up on a couple of glaring technical errors..."

    I'm good at suspension of belief (have you seen the way I dress? LOL)

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