Ion Thrusters: Not Just For TIE Fighters Anymore

March 3, 2022 by Zoe Skyforest 42 Comments

Spacecraft rocket engines come in a variety of forms and use a variety of fuels, but most rely on chemical reactions to blast propellants out of a nozzle, with the reaction force driving the spacecraft in the opposite direction. These rockets offer high thrust, but they are relatively fuel inefficient and thus, if you want a large change in velocity, you need to carry a lot of heavy fuel. Getting that fuel into orbit is costly, too!

Ion thrusters, in their various forms, offer an alternative solution – miniscule thrust, but high fuel efficiency. This tiny push won’t get you off the ground on Earth. However, when applied over a great deal of time in the vacuum of space, it can lead to a huge change in velocity, or delta V.

This manner of operation means that an ion thruster and a small mass of fuel can theoretically create a much larger delta-V than chemical rockets, perfect for long-range space missions to Mars and other applications, too. Let’s take a look at how ion thrusters work, and some of their interesting applications in the world of spacecraft!

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You Can Find Military Radars On Publicly-Available Satellite Data

March 2, 2022 by Zoe Skyforest 15 Comments

When it comes to hunting down military radar installations and associated hardware, we typically think of equipment that is firmly in the price bracket of nation states and their military forces. Whether it’s early warning radar, those used for air defence, or for naval purposes, you’d think it was relatively difficult to intercept or track these emissions.

However, a new tool built by geocomputation lecturer Ollie Ballinger shows this isn’t the case. In fact, openly-available data captured via satellite can be used to find all manner of military radar emitters. Let’s explore how!

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Review: DevTerm Linux Handheld Has Retro-Future Vibe

March 2, 2022 by Donald Papp 32 Comments

It’s not every day that an open-source, portable Linux handheld computer gets announced, so I couldn’t resist placing an order for the DevTerm by ClockworkPi back when we first learned about the stylish little terminal, which includes a 1280 x 480 screen (double-wide VGA) and a modular little thermal printer.

Of course, the global semiconductor shortage combined with shipping slowdowns led to delays, but things did ultimately come together for the project. I’ve always been a sucker for small-format machines, especially ones that come as a well-designed kit, and that means I can tell you all about what it was like to put it together and turn it on. There’s a lot to look at, so let’s get started.

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Human Power, Past And Future

March 1, 2022 by Al Williams 54 Comments

We will assume you’ve seen The Matrix — it was from 1999, after all. The surprise, at the end, was that humans were being used as human batteries to power a civilization of intelligent machines. But aside from just putting out some heat, the idea does have some precedent. After all, humans powered machines like mills, sewing machines, and pumps for centuries before there were good alternatives.

History

Galley ship — Reconstruction of a squadron of ancient Greek galley ships.

Early machines used hand cranks, treadwheels, treadles, and even pedal power to harness energy from humans. Consider, for example, an ancient galley ship with many oarsmen providing an engine. This wasn’t a great use of human power. An oarsman on a galley used his arms and back but didn’t much use his legs. The legs, though, have larger muscles and are often stronger. A pedal boat or racing shell would have been much more efficient, but without mass production of strong metal parts, it would have been difficult to build and maintain such machines in ancient times.

There was a time when pedals or treadles operated lots of machines from sewing machines to lathes. There were even old radios able to transmit and receive with no external power thanks to pedals as late as the 1940s.

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Researchers Build Neural Networks With Actual Neurons

March 1, 2022 by Zoe Skyforest 21 Comments

Neural networks have become a hot topic over the last decade, put to work on jobs from recognizing image content to generating text and even playing video games. However, these artificial neural networks are essentially just piles of maths inside a computer, and while they are capable of great things, the technology hasn’t yet shown the capability to produce genuine intelligence.

Cortical Labs, based down in Melbourne, Australia, has a different approach. Rather than rely solely on silicon, their work involves growing real biological neurons on electrode arrays, allowing them to be interfaced with digital systems. Their latest work has shown promise that these real biological neural networks can be made to learn, according to a pre-print paper that is yet to go through peer review.
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3D Printering: Giants

February 28, 2022 by Al Williams 17 Comments

Newton famously said, “If I see further than others, it is by standing upon the shoulders of giants.” For 3D printing, though, it might be the reverse. If a printer prints larger than others, it is probably using work developed for smaller printers. There are a variety of very large 3D printers out there now and you frequently see claims in the press of “world’s largest 3D printer.” Roboze, for example, makes that claim with a build volume of 1 meter on each axis.

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Logic Simulation Hack Chat With Al Williams

February 28, 2022 by Dan Maloney 3 Comments

Join us on Wednesday, March 2 at noon Pacific for the Logic Simulation Hack Chat with Al Williams!

Many of us probably remember — some fondly, some less so — our first encounter with a truth table. The little grid of ones and zeros seemed simple enough, but it held real power in its tabular representation of the output of a logic circuit for a given set of inputs. It’s what makes more complex logic circuits possible, but only up to a point — add enough gates, flip flops, and counters, and keeping track of what’s high and what’s low becomes problematic with just pencil and paper.

If you’ve reached the point where keeping your digital design in your head doesn’t work anymore, or if you never could keep your NANDs and NORs straight, then you’re ready for a digital logic simulator. Applications like Falstad and LogiSim let you build a design using everything from discrete logic gates to complete assemblies like adders, counters, and even arithmetic logic units. Add in some passives like capacitors and inductors, and a logic simulator may be the only tool you need to bring a design to life in the virtual world before ever touching a breadboard.

To help us figure out where logic simulators fit in our design processes, Hackaday Staff Writer Al Williams will hop onto the Hack Chat with us. Al ran a very successful FPGA Bootcamp series back in 2018, which included a review of digital logic using Falstad. He’ll expand on that in this Hack Chat, so come along with your questions and comments. You won’t want to miss this one!

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, March 2 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

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