Why Satellites Of The Future Will Be Built To Burn

April 22, 2019 by 33 Comments

There’s no shortage of ways a satellite in low Earth orbit can fail during the course of its mission. Even in the best case scenario, the craft needs to survive bombardment by cosmic rays and tremendous temperature variations. To have even a chance of surviving the worst, such as a hardware fault or collision with a rogue piece of space garbage, it needs to be designed with robust redundancies which can keep everything running in the face of systemic damage. Of course, before any of that can even happen it will need to survive the wild ride to space; so add high-G loads and intense vibrations to the list of things which can kill your expensive bird.

After all the meticulous engineering and expense involved in putting a satellite into orbit, you might think it would get a hero’s welcome at the end of its mission. But in fact, it’s quite the opposite. The great irony is that after all the time and effort it takes to develop a spacecraft capable of surviving the rigors of spaceflight, in the end, its operators will more than likely command the craft to destroy itself by dipping its orbit down into the Earth’s atmosphere. The final act of a properly designed satellite will likely be to commit itself to the same fiery fate it had spent years or even decades avoiding.

You might be wondering how engineers design a spacecraft that is simultaneously robust enough to survive years in the space environment while at the same time remaining just fragile enough that it completely burns up during reentry. Up until fairly recently, the simple answer is that it wasn’t really something that was taken into account. But with falling launch prices promising to make space a lot busier in the next few years, the race is on to develop new technologies which will help make sure that a satellite is only intact for as long as it needs to be.

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Video Mangler For All Your Video Mangling Needs

April 22, 2019 by 8 Comments

Back in the ’70s and ’80s, before we had computers that could do this sort of thing, there were fully analog video effects. These effects could posterize or invert the colors of a video signal, but for the best example of what these machines could do just go find some old music videos from Top of The Pops or Beat Club. Stuff gets weird, man. Unfortunately, all those analog broadcasting studios ended up in storage a few years ago, so if you want some sweet analog effects, you’re going to have to build your own. That’s exactly what [Julien]’s Video Mangler does. It rips up NTSC and PAL signals, does some weird crazy effects, and spits it right back out.

The inspiration for this build comes from an old ’80s magazine project called the ‘video palette’ that had a few circuits that blurred the image, turned everything negative, and could, if you were clever enough, become the basis for a chroma key. You can have a lot of fun when you split a video signal into its component parts, but for more lo-finess [Julien] is adding a microcontroller and a 12-bit DAC to generate signals that can be mixed in with the video signals. Yes, all of this can still be made now, even though analog TV died a decade ago.

The current status of this project is a big ‘ol board with lots of obscure chips, and as with everything that can be described as circuit bending, there’s going to be a big panel with lots of dials and switches, probably stuffed into a laser-cut enclosure. There’s a mic input for blurring the TV with audio, and enough video effects to make any grizzled broadcast engineer happy.

RIP Rex Garrod, Creator Extraordinaire

April 22, 2019 by 30 Comments

Earlier this month, the youth motocross champion, special effects creator, inventor, TV presenter, and Robot Wars competitor, [Rex Garrod] died at the age of 75 after a long battle with dementia. We do not often carry obituaries here at Hackaday, and it’s possible that if you are not a Brit you may not have heard of [Rex], but his work in the time before YouTube would have made him an international must-watch star had he been operating in the age of on-demand Internet video.

I first became aware of Rex when he appeared as assistant to [Tim Hunkin] on his Secret Life of Machines TV series in the late 1980s. He was the man whose job we all wanted, making the most incredible machines and operating them for our entertainment. Our Hardware heroes tribute to [Tim] has a picture of him operating the needle on a giant mock-up of a sewing machine, but he appeared in many more episodes. Of the many tributes to [Rex] that have appeared over the last few days it is [Tim]’s one that probably says the most about his appeal to our community. His propensity for picking up interesting parts from junkyards strikes a chord, and the tale of hugely overpowering car wiper motors by allowing them to be submerged in water is pure genius.

To a slightly younger generation he is best known for his appearances in the British Robot Wars series‘ with his Cassius series of fighting robots. He created one of the first really potent flipper robots in UK robotic combat, and incidentally the first effective self-righting mechanism. As one of the many members of the SMIDSY team that didn’t appear on the recorded TV series’ I encountered him only peripherally, but I remember his work being a major influence on SMIDSY’s run-any-way-up design. Meanwhile for a younger generation still he created the models for the popular children’s TV character Brum, an anthropomorphised scale-model Austin 7 car.

We’ll leave you with a couple of videos featuring [Rex]. The first is from The Secret Life of Machines, in which along with [Tim] he helps explain electronics from first principles, while the second is a fan-created medley of his Robot Wars appearances. Rest in peace [Rex], and thank you.

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A High-Speed Slide Scanner Build

April 21, 2019 by 19 Comments

Photographic slides were popular in the middle part of the 20th century, but are long forgotten now. If you’ve found a handful in a dusty attic, you might consider sending them away to be digitized professionally, or using a flatbed scanner at home. [Bryan Howard] found himself with over 200,000 slides, however, so that just wouldn’t do. Instead, he endeavored to build an automated scanner of his own. 

Like many similar projects, [Bryan] started with an existing slide projector as a base. This means that all the difficult work of slide transport is already taken care of. The projector has then been upgraded with an LED light source and other tweaks befitting its new role. An Arduino Pro Micro runs the show, firing off the camera to image each slide before loading the next one into place. The DSLR responsible for imaging is then hooked up to a PC so the incoming images can be checked while the machine is in operation.

Preliminary tests are promising, with the scanner successfully capturing several slides in a row. [Bryan] estimates that, with a capture time of between 1 and 2 seconds per slide, it should take somewhere between 2-5 days to image the entire collection.

We wish [Bryan] the best of luck with the project, and look forward to seeing the final results. We’ve seen similar work before, too. Video after the break.

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Build Your Own Freezer With Thermoelectric Coolers

April 21, 2019 by 40 Comments

Freezers are highly useful devices. You can preserve food, stop a dead animal from stinking out your apartment, and keep your vodka at the optimal drinking temperature. Of course, most of us bought ours from the local whitegoods store, but [Tech Ingredients] set out to build his own (YouTube, embedded below).

Unlike your freezer at home, this build doesn’t use the typical heat pump and refrigeration cycle with a compressor and expansion valve and so on. Instead, this freezer uses thermoelectric devices to pump heat, in combination with a glycol cooling circuit and fan-cooled radiators.

It’s not the most efficient or practical way to build a freezer, but it is functional and the device demonstrably works, making ice cubes over the course of a few hours. Performance can be further improved by moving the radiator assembly outdoors to make the most of the low ambient temperatures.

[Tech Ingredients] has further plans to experiment with a dessicant-based refrigeration system, and reports that initial results are promising. We’re eager to see how that goes; we’re fans of any rig that can cool a beer down in no time flat. Video after the break.

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Hackaday Links: April 21, 2019

April 21, 2019 by 16 Comments

A Russian company has developed a drone with a very interesting control scheme. It’s a VTOL fixed wing, that takes off like a bicopter, transitions to use wings for lift, flies around for half an hour or so, and then lands on its tail. This is a big ‘un; the reported weight is 50 pounds. Although the available footage really doesn’t give any sense of scale, we would estimate the wingspan as somewhere between four and five feet. Fixed-wing VTOLs are close to the holy grail of current drone science — wings actually generate lift, and VTOL means Uber can deliver McDonalds to your driveway.

What happens when you give an idiot a USB killer? $60,000 in damages. A former student at the College of St. Rose killed 59 computers with a USB killer, basically a charge pump that dumps a hundred or so volts back into a USB port, destroying the computer. Yes, you can just buy USB killers on the Internet, and yes you can film yourself zapping computers and posting the videos on social media. Both are dumb ideas.

This week was huge for the preservation of our digital culture. The source for the original Infocom games, such as Zork and Hitchhiker’s Guide to the Galaxy have been archived and released. This is a rather interesting development, as these games were written in Zork Implementation Lanugage (ZIL), a language that is used by no one and there’s almost zero documentation. Yes, we have the source, but not a compiler. It’s Lisp-ish, and there are people working to make new games in this language. Also this week is the release of the source for Leisure Suit Larry. Hackaday readers will be familiar with Leisure Suit Larry as the protagonist is a 38-year-old loser who lives in his mother’s basement. This game goes off the rails when the protagonist decides to leave the basement, but it was written a long time ago, and I guess Al Lowe didn’t foresee the Internet or something. Tip of the very fancy hat to @textfiles here.

You in Jersey? The Vintage Computer Festival East is May 3-5th, and it’s bound to be a grand time. Keynotes are by Steve Bellovin, co-inventor of USENET, Ken Thompson (!), co-inventor of UNIX, and Joe Decuir, co-inventor of the Atari VCS, Atari 800, and the Commodore Amiga. There’s also a Software Store (new this year), which we can only hope is like walking into Babbage’s. Protip: while you’re there, go up to Asbury Park and visit the Silverball Museum. It’s a whole lot of pinball.

For easier production and assembly of circuit boards, you should only place your components on one side. Doing so means you don’t have to flip the board and run it through the pick and place again, and you don’t have to worry about glue. This is a single-sided circuit board. There’s only one side. It’s a Mobius PCB, the flex-circuit version of a handmade circuit board made with a conductive pen.

Making A Flying Wing With Expanding Foam

April 21, 2019 by 9 Comments

Many radio control aircraft modelers will be familiar with the process of cutting wings out of foam with the hot wire method. The tools are simple enough to build at home, and it’s an easy way of producing a lightweight set of wings without too much hassle. [IkyAlvin] walks a different path, however (YouTube link, embedded below).

Expanding foam is the key here – that wonderful sticky material in a can that never quite goes where you want it to. MDF and foam is used to create a mold to produce the wing forms. It’s then a simple matter of loading floor underlay into the mold to act as the outer skin, and then filling the mold with expanding foam and waiting for it to cure.

The final parts are assembled into a flying wing, and the first test flight is remarkably successful. Using foam overlay as a skin also has the added benefit of providing a sleek silver finish to the aircraft. It goes to show that there’s always room to explore alternative techniques outside of the mainstream. If you’d like to get more familiar with the classic hot wire technique, though, we can help there too. Video after the break.

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