Link: https://www.space.com/technology/acceleration-without-fuel-revolutionary-superconducting-thruster-harnesses-earths-magnetic-field-in-1st-orbital-test

..."Once you have super-conducting technology available in space, you can then create very strong magnetic fields and you can use them for various use cases," he said. "You can accelerate things in space very fast or change the trajectory of a satellite completely without fuel."...

"When we go to space, we get hurt by radiation, and these superconducting magnets can create umbrellas of magnetic fields around the spacecraft to protect the interior," said Arshavsky. "So we can shield people in space from that radiation."...

Making a superconductor is easy. Keeping a superconductor is hard.

Except right now, superconductors only work at very low temperatures, and keeping things at low temps in space requires energy.

Energy is easy enough to get in space with some solar panels and a battery, while fuel has to be sent with the payload. Even if it's not good enough for constant function, being able to spin them up long enough for a course correction is a pretty big deal.

No, keeping parts of things cold in space is easy. As long as something isn't being hit by direct solar radiation then the default temperature is negative several hundred degrees

Is there a limit to the amount of thrust that these superconducting magnets could generate in Earth's magnetic field? I read a hypothesis that the UAPs that have been observed to accelerate without any propellent are using superconductors in this way.

Technically, it needs insulation and a way to radiate heat. I read a while back that the superconductors used in space are often wrapped in several concentric shells to avoid being exposed directly to the sun and other onboard heat sources.

Technically yes, due to the extreme distances between particles in space we'd average a volume and say "negative temperature!".

However.

Those individual particles are shooting at extreme speed and momentum, so they're individually very hot.

And due to the lack of particles bouncing around in a given volume of space, you can't use conduction/convection (aka, here fellow particles, take some of my energy). Instead you can only use radiative cooling, which is crazy inefficient. For example, the ISS has 75KW of cooling across 1000 square meters.

But once it's cool it stays cool. Anything behind a radiation shield will stay cool forever

Much like my erection.

it makes the most sense, right?

No

Until it turns on. Then boom, waste heat.

"""easy"""

A magnet that strong would be easily detected by human technology

Are we finally going to get flying cars and hover boards?

Don't UFOs often come with a "my stuff started going haywire" type of thing? Are we monitoring the atmosphere for transient localized magnetic anomalies?

This does not move anything in orbit at all, it's only for turning. It's better than using cold gas thrusters for turning, but this will not move you to a different point at all.

this is for applying torque to the spacecraft, not generating thrust. these are just magnetorquers, which have been a thing for a while. the only thing new here is that they use superconducting magnets, which i assume just means they can more efficiently create magnetic fields. its cool but its not really a game changing development, more a refinement on an existing technology. science journalism has to make everything sexy for clicks though...

I'm pretty sure weather services and the military measure stuff like that. If UAPs were as common as the believers think, there would have been actual evidence by now.

That's true for older magnetorquers, because the Earth's magnetic field is smooth enough that the difference between field strength at the top and bottom of the satellite is insignificant.

With superconductors you can scale up the magnetic field strength enough to get a usable net linear force.

Right, but then it's not really "without fuel." It's hopefully less fuel, and if you can run it on solar panels, it would be without resupply, but nuclear power could also provide long-term functionality. As always, the most fuel is spent getting things into orbit.

For me, the exciting bit is the magnetic radiation shielding. If we're going to leave earth behind, radiation shielding is currently a significant missing piece of the puzzle.

No (and even if we did, you would never be able to afford one)

They're not claiming the launch won't use fuel, just manoeuvring in space, which still solves the problem of getting fuel for manoeuvring while in space. Fuelless launches are a separate issue that other people are working on.

Though in all fairness that isn't much of a problem for a superconductor - no resistance, no waste heat when power runs through it.

The main problem would be the waste heat from the rest of the system rather than the superconductor itself, so maintaining a superconductor cool is more a thermal insulation problem and the near vacuum of space actually helps in doing it because it removes the heat transmission from the hotter parts of the system to the superconductor via the environment (though, of course, it still happens via the solid parts in contact with it, so the thermal insulation is needed there)

wtf are you talking about... linear and angular momentum are always conserved. the only way to get thrust is to expend mass. a magnetorquer exchanges angular momentum with the earth via its magnetic field. it cant be used to exchange linear momentum.

i mean, yes. You can make YCBO superconductors by just heating some powders to 1000°C.
Like okay you can't do it on the stove, but it's also perfectly achievable by anyone with a back yard.