Superconducting Thruster Harnesses Earth's Magnetic Field In First Orbital Test
- Reference: 0184349080
- News link: https://science.slashdot.org/story/26/07/07/2327219/superconducting-thruster-harnesses-earths-magnetic-field-in-first-orbital-test
- Source link:
> The tests began shortly after Mira's launch in November last year aboard the SpaceX Transporter 12 mission and saw the shoebox-size device perform with flying colors, Zenno Astronautics CEO and founder Max Arshavsky, told Space.com. "It's a technology that allows a spacecraft to not tumble violently in space and point in the right direction," Arshavsky said. "The unit has multiple super-conducting magnets that are positioned in different axes. When we power up the magnets, they generate a magnetic field, which interacts with Earth's magnetic field, and because we can control the magnetic field on the satellite, we can control the way in which it turns with respect to Earth."
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> Superconducting magnets are made of coils of superconducting wire that have zero electrical resistance and can therefore conduct much larger currents than normal wires. That larger current translates into a greater magnetic force. There is, however, a catch: Superconducting materials need to be cooled to extremely low temperatures to gain their wonder properties. [...] The unit housing the superconducting magnets is wrapped in layers of insulation and fitted with a heat pump that removes all the excess heat from the system. Every time the satellite needs a push, the superconducting coils power up, drawing energy from a battery charged by the satellite's solar panels.
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> "It's converting solar energy straight into useful work," Arshavsky said. "Energy is the one thing that is abundant in space, and you can use it to energize the magnet to create a magnetic acceleration device. It gives you acceleration without fuel." In the future, Zenno Astronautics plans to launch larger systems that could enable spacecraft to dock in space or conduct close proximity operations using just the power of their solar-powered superconducting magnets. Arshavsky envisions powerful magnets that could, in the future, propel spacecraft on missions to the moon and Mars using only solar power.
[1] https://www.space.com/technology/acceleration-without-fuel-revolutionary-superconducting-thruster-harnesses-earths-magnetic-field-in-1st-orbital-test
Confused by claims (Score:2)
I am confused by this company's claims. It sounds very much like a [1]magnatorquer [wikipedia.org] - a device that can change a spacecraft's orientation - that just happens to use superconducting magnets instead of, say, copper wire. That's cool, and will certainly have useful applications.
But then they start talking about using it for propulsion, which I'm confused by. To get propulsion pretty much always requires reaction mass - something you're throwing behind the spacecraft. This doesn't do that, so how is it suppo
[1] https://en.wikipedia.org/w/index.php?title=Magnetorquer&oldid=1313752913
Re: (Score:2)
Did you never play with magnets and observe that when you place like poles next to each other they push away instead of attract?
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Yes, but you have to have a magnetic field to push against.
In Earth orbit the device can interact with the Earth's magnetic field, but propulsion to the moon or Mars?
What will it push against? How powerful is the sun's magnetic field at that distance?
Re: (Score:2)
Maybe they plan to push off the Earth's magnetic field and then very very slowly drift to Mars.
That bit sounds daft, but for boosting satellites in orbit it makes much more sense.
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Yea it sounds like marketing fluff. Unless they can gather a lot of solar power, it seems like any attempt to thrust to the moon would take several months or years. I wonder if they even have such a test planned? Maybe at the end of their chart in the "if we somehow have a lot of left over money" phase.
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Months to the moon would be useful if the mass was decent. Micro sats are the obvious choice, but even if they could very slowly move a lander there, the transit time isn't a big deal.
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Getting to the moon, or mars, in general only requires a single push. Without drag there is nothing to slow down the spacecraft afterwards and you don't need to keep pushing. So you can push once against the magnetic field of the earth if you are pointed in the right direction, and also get to your destination in a reasonable amount of time. The actual questions are: 1. can you push hard enough for accelerating to a reasonable velocity within a reasonable time? 2. What about correction burns/pushes? I suppo
Re: (Score:2)
My take is this may (or may not) make station-keeping for satellites cheaper, weight less and be more reliable (as solid-state).
For "Mars", this is probably only for multi-year non-manned missions. If viable at all, that is. Probably some PR person hallucinated that part.
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It wouldn't be for manned missions...except possibly for cargo robots that plan to take a really long time.
OTOH, the sun also has a magnetic field, so this should work (to an extent!!) throughout the solar system. Which doesn't mean it would ever be practical for that no matter how developed. But for station-keeping in Earth orbit it might be more than sufficient.
Re: Confused by claims (Score:2)
Insane Clown Posse, is that you?
Re: (Score:2)
> To get propulsion pretty much always requires reaction mass
Requires momentum, to be precise. To date, the easiest way to generate momentum is to throw gobs of mass* out the back end of a rocket engine. But it can also be done with solar sails, for example. Which involve photons (zero mass).
*Sorry about these esoteric technical terms.
It reacts against the thing producing the field (Score:2)
The spacecraft reacts against the Earth, the source of the magnetic field it's working within. The Earth is just so much more massive than the spacecraft that it doesn't affect it very much. It's much like when you jump, you're reacting against the Earth by pushing against it directly. It reacts against the Earth via electromagnetic forces rather than physically pushing against it.
delusions of grandeur (Score:1)
The irrationally exuberant inventors can't help themselves. "... and Mars using only solar power." Like there's also plenty of magnetic field to push against everywhere.
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I wouldn't go so far as to say "plenty of magnetic field to push against", but there literally *is* magnetic field everywhere. The intensity and direction varies a lot depending on solar weather, to position of Jupiter, solar weather, etc., and magnetic field strength, IIRC, drops off as the 4th power of distance, so a lot of places it's going to be REALLY weak, but it *will* be present.
n-body problem (Score:2)
> conduct close proximity operations using just the power of their solar-powered superconducting magnets
So you would also need to provide for the interaction between the different magnets. I guess if it's all yours, you could orchestrate it better.
free power (Score:2)
Now if we wrap Earth in a few coils of copper wire and position those magnets just right...
Cool tech... (Score:2)
Kiwis should be proud of this.
wow, clever. (Score:1)
how long can such a satellite stay up there?
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From the last paragraph it says "It gives you acceleration without fuel" and "could, in the future, propel spacecraft on missions to the moon and Mars using only solar power". From that I would assume it has the potential to boost it's orbit to counter any orbital decay, and therefor stay in orbit indefinitely. With suitable quality parts and construction I would assume it could be decades.
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Getting to Mars though... As it gets further from Earth, the magnetic field weakens, and it's not very strong to start with. The acceleration in orbit is going to be small. Maybe if you can take a century to get to Mars it might be feasible.
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This would probably only be with real thrust at start end end.
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Actually, there should always be SOME amount of thrust available. It should be more powerful than a solar sail of equivalent size, and much more directional. But don't expect any large amount of thrust. (OTOH, the solar sail would be a LOT cheaper and more reliable. And "equivalent size" is doing a lot of work there.)
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This would be similar to the ion drive. A small but continuous thrust is extremely effective. For unmanned flights, time is less of a factor anyway. This is an important technology and real use cases IMO.
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Previous planetary probes have done figure-8s around the Earth & Moon to build up velocity before heading off for their target planets, so you could possibly do something similar with this to shorten the transit time; a few laps to provide initial acceleration to escape velocity, then coast to Mars using the panels to keep any systems ticking over and batteries topped off. Mars orbital insertion might need a little thought as to how to manage deceleration, or a secondary means of braking propulsion, if
Well...let's run some numbers. (Score:3)
Cool idea for satellites near the earth. The thrust will be pretty minimal, but since it's basically "free" that doesn't matter.
Moon and Mars...hmmm...gonna be a slight lack of magnetic fields to push against, as soon as you are away from the Earth. Neither the Moon nor Mars has a significant magnetic field.
ChatGPT points out that the magnets are likely more useful to maintain orientation. Any actual thrust will be on the order of nano-newtons. Let's be generous and assume an entire micronewton of thrust,
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As long as the hardware works. In space, that may not be that long.