The Price Of Space

January 28, 2016 by Al Williams 61 Comments

Many engineers of a certain age have one thing in common: Their early interest in science and engineering came from watching the US and Russian space programs. To me, regardless of any other benefit from the space program (and there are many), that ability to inspire a future generation of engineers made the entire program worthwhile.

We live in a world where kids’ role models are more likely to be sports or entertainment figures that have regular visits to police stations, jails, and rehab centers. The value of having role models that “do science” is invaluable.

This time of the year is a dark time for NASA missions, though. On January 27, 1967, the Apollo I crew (Grissom, White, and Chaffee) died in a fire. The investigation led to NASA limiting how much Velcro you can use in a cabin and moving away from pure oxygen in the cabin.

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Bone Up On Your Multiplication Skills

January 25, 2016 by Kristina Panos 5 Comments

John Napier was a Scottish physicist, mathematician, and astronomer who usually gets the credit for inventing logarithms. But his contributions to simplifying mathematics and building shorthand solutions didn’t end there. In the course of performing the many calculations he needed to practice these subjects in the 1500s, Napier invented a kind of computing mechanism for multiplication. It’s a physical manifestation of an old system known as lattice multiplication or gelosia.

Lattice multiplication makes use of the multiplication table in order to multiply huge numbers together quickly and easily. It is thought to have originated in India and moved west into Europe. When the lattice method reached Italy, the Italians named it gelosia after the trellised window covering it resembled, which was commonly used to keep prying eyes away from one’s possessions and wife.

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Wolfenstein In 600 Lines Of Code

January 15, 2016 by Mike Szczys 62 Comments

What’s more impressive, the fact that this Wolfenstein-like game is 600 lines of code, or that it’s written in AWK?

AWK is a language primarily used for text processing. But if you can write code the world bows to your wishes. [Fedor Kalugin] leverages the ability of a Linux terminal’s color options to draw his game. The 3D aspect is produced through ray-casting which generates a 2D image from 3D coordinates.

Trying out the game is extremely simple, install gawk, clone the repo, and play:

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An Incredible Clock Made Of Popsicle Sticks

January 9, 2016 by Gerrit Coetzee 13 Comments

[alvenh] has come a long way since he was a kid, but he kept the bag of popsicle sticks from his childhood. When he set out to build a clock for himself, he remembered his stored treasure and made something unexpectedly good out of the humble material. We’ve seen some neat stuff made with popsicle sticks before, but they usually retain their familiar shape.

[alvenh] began by choosing a style for his clock. We don’t know how he looked at a bag of sticks and thought, “Old English Georgian bracket clock with a bell top,” but if Hackaday teaches anything, it’s that some people just have a wider vision for the world. Next he laminated the sticks together or used them as a veneer for a thinner sheet of plywood to make his base materials.

An incredible amount of work went into the clock as he did things like sanding large contours using a jar for a form, or cutting mortise and tenons into craft sticks. [alvenh] even painted the face of the clock using his German Shepard as a model. Finally he installed an antique movement into the creation. The final result is stunning, and the build log is fun to read through.

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The 3D Printers Of CES

January 6, 2016 by Brian Benchoff 65 Comments

CES, the Consumer Electronics Show, is in full swing. That means the Hackaday tip line is filled to the brim with uninteresting press releases, and notices that companies from the world over will be at CES.

3D printing has fallen off the radar of people who worship shiny new gadgets of late, and this is simply a function of 3D printing falling into the trough of disillusionment. The hype train of 3D printing is stuck on a siding, people are bored, but this is the time that will shape what 3D printing will become for the next ten years. What fascinating news from the 3D printing industry comes to us from CES?

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Shark With Frickin’ LED Tells People Not To Bother You

January 1, 2016 by Dan Maloney 5 Comments

Everybody is busy these days, but sometimes it’s hard to tell. What with teleconferences being conducted over tiny Bluetooth headphones and Skype meetings where we seem to be dozing in front of the monitor, we’ve lost some of the visual cues that used to advertise our availability. So why not help your colleagues to know when to give you space with this shark themed WiFi-enabled meeting light?

Why a shark and not a mutated intemperate sea bass? Only [falldeaf] can answer that. But the particulars of the build are well-documented and pretty straightforward. A Photon runs the show, looking for an Outlook VFB file to parse. An RGB LED is used to change the color of the translucent 3D printed shark based on whether you’re in a meeting, about to step into one, or free. The case is 3D printed as well, although [falldeaf] farmed the prints out to a commercial printing outfit because of the size and intricacy of the parts. He did fabricate a nice looking wood base for the light, though.

There are plenty of ways to tell people to buzz off, but this is a pretty slick solution. For those in open floor plan workspaces, something like this IoT traffic light for you and your cube-mates might be in order.

32C3: So You Want To Build A Satellite?

December 31, 2015 by Elliot Williams 46 Comments

[INCO] gave this extremely informative talk on building a CubeSat. CubeSats are small satellites that piggyback on the launches of larger satellites, and although getting a 10 cm³ brick into orbit is cheap, making it functional takes an amazing attention to detail and redundant design.

[INCO] somehow talks through the entire hour-long presentation at a tremendous speed, all the while remaining intelligible. At the end of the talk, you’ve got a good appreciation for the myriad pitfalls that go along with designing a satellite, and a lot of this material is relevant, although often in a simpler form, for high altitude balloon experiments.

CubeSats must be powered down during launch, with no radio emissions or anything else that might interfere with the rocket that’s carrying them. The satellites are then packed into a box with a spring, and you never see or hear from them again until the hatch is opened and they’re pushed out into space.

[INCO] said that 50% of CubeSats fail on deployment, and to avoid being one of the statistics, you need to thoroughly test your deployment mechanisms. Test after shaking, being heated and cooled, subject to low battery levels, and in a vacuum. Communication with the satellite is of course crucial, and [INCO] suggests sending out a beacon shortly after launch to help you locate the satellite at all.

Because your satellite is floating out in space, even tiny little forces can throw it off course. Examples include radiation pressure from the sun, and anything magnetic in your satellite that will create a torque with respect to the Earth’s magnetic field. And of course, the deployment itself may leave your satellite tumbling slightly, so you’re going to need to control your satellite’s attitude.

Power is of course crucial, and in space that means solar cells. Managing solar cells, charging lithium batteries, and smoothing out the power cycles as the satellite enters the earth’s shadow or tumbles around out of control in space. Frequent charging and discharging of the battery is tough on it, so you’ll want to keep your charge/discharge cycles under 20% of the battery’s nominal capacity.

In outer space, your satellite will be bombarded by heavy ions that can short-circuit the transistors inside any IC. Sometimes, these transistors get stuck shorted, and the only way to fix the latch-up condition is to kill power for a little bit. For that reason, you’ll want to include latch-up detectors in the power supply to reset the satellite automatically when this happens. But this means that your code needs to expect occasional unscheduled resets, which in turn means that you need to think about how to save state and re-synchronize your timing, etc.

In short, there are a ridiculous amount of details that you have to attend to and think through before building your own CubeSat. We’ve just scratched the surface of [INCO]’s advice, but if we had to put the talk in a Tweet, we’d write “test everything, and have a plan B whenever possible”. This is, after all, rocket science.