Open-Source Satellite Propulsion Hack Chat

Join us on Wednesday, December 11 at noon Pacific for the Open-Source Satellite Propulsion Hack Chat with Michael Bretti!

When you look back on the development history of any technology, it’s clear that the successful products eventually reach an inflection point, the boundary between when it was a niche product and when it seems everyone has one. Take 3D-printers, for instance; for years you needed to build one if you wanted one, but now you can buy them in the grocery store.

It seems like we might be getting closer to the day when satellites reach a similar inflection point. What was once the province of nations with deep pockets and military muscles to flex has become far more approachable to those of more modest means. While launching satellites is still prohibitive and will probably remain so for years to come,  building them has come way, way down the curve lately, such that amateur radio operators have constellations of satellites at their disposal, small companies are looking seriously at what satellites can offer, and even STEM programs are starting to get students involved in satellite engineering.

Michael Bretti is on the leading edge of the trend toward making satellites more DIY friendly. He formed Applied Ion Systems to address one of the main problems nano-satellites face: propulsion. He is currently working on a range of open-source plasma thrusters for PocketQube satellites, a format that’s an eighth the size of the popular CubeSat format. His solid-fuel electric thrusters are intended to help these diminutive satellites keep station and stay in orbit longer than their propulsion-less cousins. And if all goes well, someday you’ll be able to buy them off-the-shelf.

Join us for the Hack Chat as Michael discusses the design of plasma thrusters, the details of his latest testing, and the challenges of creating something that needs to work in space.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 11 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Cold Plasma Torch Produces A Cleansing Flame That Never Consumes

It’s basically a lightsaber. Except smaller. And with an invisible blade. And cold to the touch. But other than that, this homebrew cold plasma torch (YouTube, embedded below) is just like the Jedi’s choice in elegant weaponry.

Perhaps we shouldn’t kid [Justin] given how hard he worked on this project – seventeen prototypes before hitting on the version seen in the video below – but he himself notes the underwhelming appearance of the torch without the benefit of long-exposure photography. That doesn’t detract from how cool this build is, pun intended. As [Justin] explains, cold plasma or non-equilibrium plasma is an ionized stream of gas where the electron temperature is much hotter than the temperature of the heavier, more thermally conductive species in the stream. It’s pretty common stuff, seen commercially in everything from mercury vapor lamps to microbial sterilization.

It’s the latter use that piqued [Justin]’s interest and resulted in a solid year of prototyping before dialing in a design using a flyback transformer to delivery the high voltage to a stream of argon flowing inside a capillary tube. The quartz tube acts as a dielectric that keeps electrons from escaping and allows argon to be ionized and wafted gently from the tube before it can reach thermal equilibrium. The result is a faint blue glowing flame that’s barely above room temperature but still has all the reactive properties of a plasma. The video shows all the details of construction and shows the torch in action.

Hats off to [Justin] for sticking with a difficult build and coming through it with an interesting and useful device. We’ve no doubt he’ll put it to good use in his DIY biohacking lab in the coming months.

Continue reading “Cold Plasma Torch Produces A Cleansing Flame That Never Consumes”

Ion Powered Airplane: Not Coming To An Airport Near You

Not that we don’t love Star Trek, but the writers could never decide if ion propulsion was super high tech (Spock’s Brain) or something they used every day (The Menagerie). Regardless, ion propulsion is real and we have it today on more than one spacecraft. However, MIT recently demonstrated an ion-powered airplane. How exciting! An airplane with no moving parts that runs on electricity. Air travel will change forever, right? According to [Real Engineering], ion-propelled (full-sized) aircraft run into problems with the laws of physics. You can see the video explaining that, below.

To understand why, you need to know two things: how ion drive works and how the engines differ when using them in an atmosphere. Let’s start with a space-based ion engine, a topic we’ve covered before. Atoms are turned into ions which are accelerated electrically. So the ion engine is just using electricity to create thrust exhaust instead of burning rocket fuel.

Continue reading “Ion Powered Airplane: Not Coming To An Airport Near You”

Neon Lamps Light Up Dim Ion Motor

Small pinwheel type ion motors fall into the category of a fun science experiment or something neat to do with high voltage, but Hackaday’s own [Manuel Rodriguez-Achach] added a neat twist that incorporates neon lamps.

Normally you’d take a straight wire and make 90 degree bends at either end but pointing in opposite directions, balance it on a pole, and apply a high voltage with a moderate amount of current. The wire starts spinning around at the top of the pole, provided the ends of the wire are sharp enough or the wire has a small enough diameter. If your power supply has ample current available then in the dark you’ll even see a purplish glow, called a corona, at the tips of the wire.

[Manuel] made just such an ion motor but his power supply didn’t have the necessary current to produce a strong enough corona to be visible to his camera. So he very cleverly soldered neon lamps on the two ends of the wires. One leg of each lamp goes to the wire and the other end of the lamp acts as the sharp point left out in the air for emitting the ions.

The voltage needed across each lamp in order to ignite it is that between the high voltage power supply’s output and the potential of the surrounding air. That air may be initially at ground potential but he also bends the other output terminal of the power supply such that its tip is also up in the air. This way it sprays ions of the opposite polarity into the surrounding air.

Either way, the neon lamps light up and the wire spins around on the pole. Now, even without a visible corona, his ion motor makes an awesome display. Check it out in the video below.

For more about these ion motors, sometimes called electric whirls, check our article about all sorts of interesting non-electromagnetic motors.

Continue reading “Neon Lamps Light Up Dim Ion Motor”

Practical Plasma For Thin-Film Deposition

[Nixie] wants to sputter. We know, who doesn’t? But [Nixie] has a specific purpose for his sputtering: thin-film deposition, presumably in support of awesome science. But getting to that point requires a set of tools that aren’t exactly off-the-shelf items, so he’s building out a DIY sputtering rig on the cheap.

If you’re not familiar with sputtering, that’s understandable. In this context, sputtering is a process that transfers particles from one solid to another by bombarding the first solid with some sort of energetic particles, usually electrons or a plasma. When properly controlled, sputtering has applications from mass spectrometry to the semiconductor industry, where it’s used to either deposit thin films on silicon wafers or etch them away selectively.

No matter the application, sputtering needs a stable stream of plasma. [Nixie] has posted a series of articles on his blog walking us through his plasma experiments, from pulling a really strong vacuum to building a high-voltage power supply from a microwave oven transformer. It’s a project that needs a deep well of skills and tools, like glassworking, machining, and high-voltage electronics. Check out the plasma in the video below.

Will [Nixie] be using this for a DIY fab lab? Will it be used to make homebrew LEDs? The world waits to hear.

Continue reading “Practical Plasma For Thin-Film Deposition”

Photograph Of Single Atom Captured With A Plain Old Camera

The Engineering and Physical Sciences Research Council awarded a remarkable photograph its overall prize in science photography. The subject of the photograph? A single atom visible to the naked eye. Well, perhaps not exactly the naked eye, but without a microscope. In the picture above (click here to enlarge), the atom is that pale blue dot between the two needle-like structures.

You probably learned in school that you couldn’t see a single atom, and that’s usually true. But [David Nadlinger] from the University of Oxford, trapped a positively charged strontium atom in an ion trap and then irradiated it with a blue-violet laser. The atom absorbs and reemits the light, and a camera can pick up the light, creating a one-of-a-kind photograph. The camera was a Canon 5D Mk II with a 50mm f/1.8 lens — a nice camera, but nothing too exotic.

The ion trap keeps the single atom balanced between two small needle points about 2 millimeters apart. [Nadlinger] did some math that convinced him the photograph could be possible and made it a reality on a Sunday afternoon. The pale dot isn’t especially spectacular by itself, but when you realize that it is the visual effect of a single atom, it is mind-blowing. Turns out, the lab has taken some similar photographs in the past. They don’t remember who took it, but they have a picture of 9 calcium-43 ions trapped, that you can seen below. The ions are 10 microns apart and at an effective temperature of 0.001 degrees Kelvin.

Other winning photographs included patterns on a soap bubble, an EEG headset in use, and microbubbles used to deliver drugs. There’s also an underwater robot, a machine for molecular beam epitaxy that looks like a James Bond villain’s torture device, and lattices made with selective laser melting 3D printing.

If you want to look at atoms from the comfort of your own home, maybe you should build an STM. You might even try NIST’s improved atom probe while you are at it. Just remember you can’t trust atoms. They make up everything.

Photo credit: David Nadlinger

Bicycle Racing In Space Could Be A Thing

It’s 2100 AD, and hackers and normals live together in mile-long habitats in the Earth-Moon system. The habitat is spun up so that the gravity inside is that of Earth, and for exercise, the normals cycle around on bike paths. But the hackers do their cycling outside, in the vacuum of space.

How so? With ion thrusters, rocketing out xenon gas as the propellant. And the source of power? Ultimately that’s the hackers’ legs, pedaling away at a drive system that turns two large Wimshurst machines.

Those Wimshurst machines then produce the high voltage needed for the thruster’s ionization as well as the charge flow. They’re also what gives the space bike it’s distinctly bicycle-like appearance. And based on the calculations below, this may someday work!

Continue reading “Bicycle Racing In Space Could Be A Thing”