Hacking When It Counts: Much Space Station Hacking Saved Skylab

October 14, 2015 by 45 Comments

Thanks to the seminal work of Howard and Hanks et al, the world is intimately familiar with the story behind perhaps the most epic hack of all time, the saving of the crippled Apollo 13 mission. But Apollo 13 is far from the only story of heroic space hacks. From the repairs to fix the blinded Hubble Space Telescope to the dodgy cooling system and other fixes on the International Space Station, both manned and unmanned spaceflight can be looked at as a series of hacks and repairs.

Long before the ISS, though, America’s first manned space station, Skylab, very nearly never came to fruition. Damaged during launch and crippled both electrically and thermally, the entire program was almost scrapped before the first crew ever arrived. This is the story of how Skylab came to be, how a team came together to fix a series of problems, and how Skylab went on to success despite having the deck stacked against her from the start.

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Graphene Grown On Semiconductors Big Step Toward Manufacturability

October 14, 2015 by 11 Comments

No modern technology has been met with more hype than graphene. These single-layer sheets of carbon promise everything from incredibly efficient power grids to more advanced electronics to literal elevators to space. Until now, though, researchers have yet to produce graphene sheets or ribbons in a reliable way. Researchers at the University of Wisconsin at Madison and the US Department of Energy Argonne National Laboratory have done just that, growing graphene nanoribbons on the surface of a germanium crystal.

By using a germanium crystal as a substrate, the researchers have found a directionality to the way these graphene nanoribbons form. This has been a problem for researchers experimenting with graphene microelectronics in the past; labs experimenting with making transistors out of carbon nanotubes found growth is highly unpredictable. The controlled growth of graphene nanoribbons opens the door to more precise fabrication, something that is necessary for microelectronics fabrication.

Synthesis of nanoribbons this small have not been possible before. Because germanium itself is a semiconductor – and was used for the first transistor – this discovery may pave the way for the creation of graphene-based circuits grown using the same semiconductor fabrication processes used today.

Kids Explore Engineering With Cartoon Tech Build

October 14, 2015 by 17 Comments

“To the Tortuga!” my husband and I heard the announcement from the backyard. Our two boys, Ben (7) and Miles (3), had become pleasantly obsessed with the coolest brothers in nature – the Kratt Brothers. From the moment that these two energetic animal-loving brothers were discovered by our kids, they’ve been huge fans. Our house has been transported to the Sonora Desert where we saved a Gila Monster, then to the Australian Outback to learn about the Thorny Devil. We even went to swing with the Spider Monkeys in South America and then back to the good ‘ole U.S. of A to harness the speed of the Roadrunner – since we are, after all, a family of runners!

creaturepod-from-show
Creaturepod [Source: WildKratts Wiki]
Our boys have been the Grand Brothers for months and there are no signs of it letting up. At the end of summer, I decided to reward the kids with a Creaturepod, a plastic toy meant to look like the fictional walkie talkie of the same name used on PBS Kids’ Wild Kratts program. They loved it, but soon found that it didn’t do anything on its own. They both have wild imaginations and like to bring to life most of their play, but the toy just wasn’t doing it for them. Being that Chris and Martin Kratt are brothers in real life, and Ben and Miles Grand are brothers in real life, Ben thought it would only be right to have “real life” Creaturepods. Real walkie talkies that he could use to communicate with his friends and have Wild Kratts adventures. This natural interest provided an opportunity to make learning, designing, and building a source of fun for the boys. It is an amazing way to teach that you can change the world around you by having an idea, making a plan, and gathering everyone with the skills needed to complete the project.

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Mr. Trash Wheel Cleans Baltimore’s Harbor

October 14, 2015 by 40 Comments

Quite frankly we’re rather surprised we haven’t heard of Mr. Trash Wheel before. It’s a community project by the Baltimore Waterfront’s Healthy Harbor program where they are trying to make the harbor both swimmable and fishable by 2020. One of the coolest projects that resonates with us is Mr. Trash Wheel — a waterwheel-powered-trash-collecting-conveyor-belt. Say that 10 times fast!

It was built in early 2014, and according to the latest data it has removed a whopping 160 tons of garbage from the waterway already. Floating buoy-nets direct the garbage floating on top of the water into a narrow passage where the conveyor belt powered by a waterwheel slowly picks up the trash, and then deposits it into a large dumpster on a barge.

In fact, it’s even saved a python from the water too!

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Hand-Cranked Cyclotron

October 14, 2015 by 10 Comments

Okay, not actually a cyclotron… but this ball cyclotron is a good model for what a cyclotron does and the concepts behind it feel kooky and magical. A pair of Ping Pong balls scream around a glass bowl thanks the repulsive forces of static electricity.

It’s no surprise that this comes from Rimstar, a source we’ve grown to equate with enthralling home lab experiments like the Ion Wind powered Star Trek Enterprise. Those following closely will know that most of [Steven Dufresne’s] experiments involve high voltage and this one is no different. The same Wimshurst Machine he used in the Tea Laser demo is brought in again for this one.

A glass bowl is used for its shape and properties as an insulator. A set of electrodes are added in the form of aluminum strips. These are given opposite charges using the Wimshurst machine. Ping Pong balls coated in conductive paint are light enough to be moved by the static fields, and a good crank gets them travelling in a very fast circuit around the bowl.

When you move a crank the thought of being connected to something with a chain pops into your mind. This feels very much the same, but there is no intuitive connection between the movement of the balls and your hand on the crank. Anyone need a prop for their Halloween party?

If you don’t want to buy or build a Wimshurst machine you can use a Van De Graaff generator. Can anyone suggest other HV sources that would work well here?

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Electronic Ruler Works Out Logic Truth Tables

October 13, 2015 by 23 Comments

Like [Brad], we’ve seen a number of PCB rulers out there. [Brad] was looking to take the idea and run with it. His DigiRule is a ruler with a logic gate simulator. What he built is a mash-up between PCB rulers, and the concept of electronic business cards.

All told it simulates seven logic gates, four flip-flops, and includes a four-bit counter. On one end of the ruler a CR1220 battery feeds the 18F43K20 which is performing the logic operations using buttons and LEDs. Of course the truth tables are printed on the back silk-screen, but playing with the lights is a lot more fun. We do find it fairly amusing that the centimeters on the bottom of the ruler are notated in binary.

It makes a lot more sense to hand out rulers than business cards; people might actually use them after you leave and you can still include contact info. This form-factor also breaks the mold. You can have a lot more space on a ruler and you’re not constrained by thickness (although [Limpkin] solved that problem). While we’re on the topic of business cards [ch00f’s] USB etch-a-sketch style card and this logic-based information delivery device top our favorites list.

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Triple Frequency VFO On A Bamboo Breadboard

October 13, 2015 by 5 Comments

Historically when hams built low power (QRP) transmitters, they’d use a crystal to set the frequency. Years ago, it was common to find crystals in all sorts of radios, including scanners and handheld transceivers. Crystals are very stable and precise and it is relatively easy to make a high quality oscillator with a crystal and a few parts.

The big problem is you can’t change the frequency much without changing crystals. Making a high quality variable frequency oscillator (VFO) out of traditional components is quite a challenge. However, today you have many alternatives ranging from digital synthesis to all-in-one IC solutions that can generate stable signals in a wide range of frequencies.

[N2HTT] likes to build radio projects and he decided to take an Si5351 clock generator and turn it into a three frequency VFO for his projects. The Si5351 uses a crystal, so it is very stable. However, you can digitally convert that crystal frequency into multiple frequencies over a range of about 8kHz to 160MHz.

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