Improving Magnetoplasmadynamic Ion Thrusters With Superconductors

Ion thrusters are an amazing spacecraft propulsion technology, providing very high efficiency with relatively little fuel. Yet getting one to produce more thrust than that required to lift a sheet of A4 paper requires a lot of electricity. This is why they have been only used for applications where sustained thrust and extremely low fuel usage are important, such as the attitude management of satellites and other spacecraft. Now researchers in New Zealand have created a prototype magnetoplasmadynamic (MPD) thruster with a superconducting electromagnet that is claimed to reduce the required input power by 99% while generating a three times as strong a magnetic field.

Although MPD thrusters have been researched since the 1970s – much like their electrostatic cousins, Hall-effect thrusters – the power limitations on the average spacecraft have limited mission profiles. Through the use of a high-temperature superconducting electromagnet with an integrated cryocooler, the MPD thruster should be able to generate a very strong field, while only sipping power. Whether this works and is as reliable as hoped will be tested this year when the prototype thruster is installed on the ISS for experiments.

FreeDOS 1.4 Released

Even in 2025 there are still many applications for a simple Disk Operating System (DOS), whether this includes running legacy software (including MS-DOS games & Windows 3.x), or (embedded) systems running new software where the overhead of a full-fat Linux or BSD installation would be patently ridiculous.

This is where the FreeDOS project provides a modern, fully supported DOS, with the recent 1.4 release adding a whole range of features and updates to existing components like the FreeCOM command shell. This is the first stable release since 1.3 was released in 2022.

FreeDOS saw its first release in 1994 and has become the de facto replacement for MS-DOS — featuring many improvements to make it work well on modern hardware and a package manager to manage installed software much like on Linux & BSD. The new kernel didn’t quite make it into this release, but it and some other items will be available in the monthly test builds.

You can download the new 1.4 release here, with live & installer CD images, a USB installer and even a Floppy Edition available. System requirements include an (Intel) x86 CPU, a BIOS (or legacy UEFI mode), 640 kB of RAM and 20 MB of storage.

Why USB-C Splitters Can Cause Magic Smoke Release

Using USB for powering devices is wonderful, as it frees us from a tangle of incompatible barrel & TRS connectors, not to mention a veritable gaggle of proprietary power connectors. The unfortunate side-effect of this is that the obvious thing to do with power connectors is to introduce splitters, which can backfire horribly, especially since USB-C and USB Power Delivery (USB-PD) were introduced. The [Quiescent Current] channel on YouTube recently went over the ways in which these handy gadgets can literally turn your USB-powered devices into a smoldering pile of ashes.

Much like Qualcomm’s Quick Charge protocols, USB-PD negotiates higher voltages with the power supply, after which this same voltage will be provided to any device that’s tapped into the power supply lines of the USB connector. Since USB-C has now also taken over duties like analog audio jacks, this has increased the demand for splitters, but these introduce many risks. Unless you know how these splitters are wired inside, your spiffy smartphone may happily negotiate 20V that will subsequently fry a USB-powered speaker that was charging off the same splitter.

In the video only a resistor and LED were sacrificed to make the point, but in a real life scenario the damage probably would be significantly more expensive.

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Teardown Of A Scam Ultrasonic Cleaner

Everyone knows that ultrasonic cleaners are great, but not every device that’s marketed as an ultrasonic cleaner is necessarily such a device. In a recent video on the Cheap & Cheerful YouTube channel the difference is explored, starting with a teardown of a fake one. The first hint comes with the use of the description ‘Multifunction cleaner’ on the packaging, and the second in the form of it being powered by two AAA batteries.

Unsurprisingly, inside you find not the ultrasonic transducer that you’d expect to find in an actual ultrasonic cleaner, but rather a vibration motor. In the demonstration prior to the teardown you can see that although the device makes a similar annoying buzzing noise, it’s very different. Subsequently the video looks at a small ultrasonic cleaner and compares the two.

Among the obvious differences are that the ultrasonic cleaner is made out of metal and AC-powered, and does a much better job at cleaning things like rusty parts. The annoying thing is that although the cleaners with a vibration motor will also clean things, they rely on agitating the water in a far less aggressive way than the ultrasonic cleaner, so marketing them as something which they’re not is very unpleasant.

In the video the argument is also made that you do not want to clean PCBs with an ultrasonic cleaner, but we think that people here may have different views on that aspect.

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Remembering Betty Webb: Bletchley Park & Pentagon Code Breaker

S/Sgt Betty Vine-Stevens, Washington DC, May 1945.
S/Sgt Betty Vine-Stevens, Washington DC, May 1945.

On 31 March of this year we had to bid farewell to Charlotte Elizabeth “Betty” Webb (née Vine-Stevens) at the age of 101. She was one of the cryptanalysts who worked at Bletchley Park during World War 2, as well as being one of the few women who worked at Bletchley Park in this role. At the time existing societal biases held that women were not interested in ‘intellectual work’, but as manpower was short due to wartime mobilization, more and more women found themselves working at places like Bletchley Park in a wide variety of roles, shattering these preconceived notions.

Betty Webb had originally signed up with the Auxiliary Territorial Service (ATS), with her reasoning per a 2012 interview being that she and a couple of like-minded students felt that they ought to be serving their country, ‘rather than just making sausage rolls’. After volunteering for the ATS, she found herself being interviewed at Bletchley Park in 1941. This interview resulted in a years-long career that saw her working on German and Japanese encrypted communications, all of which had to be kept secret from then 18-year old Betty’s parents.

Until secrecy was lifted, all her environment knew was that she was a ‘secretary’ at Bletchley Park. Instead, she was fighting on the frontlines of cryptanalysis, an act which got acknowledged by both the UK and French governments years later.

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On Egyptian Pyramids And Why It’s Definitely Aliens

History is rather dull and unexciting to most people, which naturally invites exciting flights of fancy that can range from the innocent to outright conspiracies. Nobody truly believes that the astounding finds and (fully functioning) ancient mechanisms in the Indiana Jones and Uncharted franchises are real, with mostly intact ancient cities waiting for intrepid explorers along with whatever mystical sources of power, wealth or influence formed the civilization’s foundations before its tragic demise. Yet somehow Plato’s fictive Atlantis has taken on a life of its own, along with many other ‘lost’ civilizations, whether real or imagined.

Of course, if these aforementioned movies and video games were realistic, they would center around a big archaeological dig and thrilling finds like pot shards and cuneiform clay tablets, not ways to smite enemies and gain immortality. Nor would it involve solving complex mechanical puzzles to gain access to the big secret chamber, prior to walking out of the readily accessible backdoor. Reality is boring like that, which is why there’s a major temptation to spruce things up. With the Egyptian pyramids as well as similar structures around the world speaking to the human imagination, this has led to centuries of half-baked ideas and outright conspiracies.

Most recently, a questionable 2022 paper hinting at structures underneath the Pyramid of Khafre in Egypt was used for a fresh boost to old ideas involving pyramid power stations, underground cities and other fanciful conspiracies. Although we can all agree that the ancient pyramids in Egypt are true marvels of engineering, are we really on the cusp of discovering that the ancient Egyptians were actually provided with Forerunner technology by extraterrestrials?

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DIY Split Keyboard Made With A Saw

Split keyboards are becoming more popular, but because they’re still relatively niche, they can be rather expensive if you want to buy one. So why not make your own? Sure, you could assemble one from a kit, but why not take a cheap mechanical keyboard, slice it in half and just waves hands connect the two halves back together? If this thought appeals to you, then [nomolk]’s literal hackjob video should not be ignored. Make sure to enable English subtitles for the Japanese-language video.

Easy split keyboard tip: just reconnect both halves... (Credit: nomolk, YouTube)
Easy split keyboard tip: just reconnect both halves… (Credit: nomolk, YouTube)

In it, the fancy (but cheap) mechanical keyboard with Full RGB™ functionality is purchased and tested prior to meeting its demise. Although the left side with the cable and controller still works, the right side now needs to be connected, which is where a lot of tedious wires have to be soldered to repair traces.

Naturally this will go wrong, so it’s important to take a (sushi) break and admire the sunset before hurling oneself at the tracing of faulty wiring. This process and the keyboard matrix is further detailed on the blog entry (in Japanese) for this process.

Although this was perhaps easier than the other split keyboard project involving a membrane keyboard, this tongue-in-cheek project demonstrates the limits of practicality with this approach even if it could be cleaned up more with fancier wiring.

We give it full points for going the whole way, however, and making the keyboard work again in the end.

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