Autonomous Spaceplane Travels to 10 km, Lands Safely 200 km Away

Space balloons, where one sends instrument packages to the edge of space on a weather balloon, are a low-cost way to scratch the space itch. But once you’ve logged the pressure and temperature and tracked your balloon, what’s the next challenge? How about releasing an autonomous glider and having it return itself to Earth safely?

That’s what [IzzyBrand] and his cohorts did, and we have to say we’re mightily impressed. The glider itself looks like nothing to write home about: in true Flite Test fashion, it’s just a flying wing made with foam core and Coroplast reinforced with duct tape. A pair of servo-controlled elevons lies on the trailing edge of the wings, while inside the fuselage are a Raspberry Pi and a Pixhawk flight controller along with a GPS receiver. Cameras point fore and aft, a pair of 5200 mAh batteries provide the juice, and handwarmers stuffed into the avionics bay prevent freezing.

After a long series of test releases from a quadcopter, flight day finally came. Winds aloft prevented a full 30-kilometer release, so the glider was set free at 10 kilometers. The glider then proceeded to a pre-programmed landing zone over 80 kilometers from the release point. At one point the winds were literally pushing the glider backward, but the little plane prevailed and eventually spiraled down to a perfect landing.

We’ve been covering space balloons for a while, but take a moment to consider the accomplishment presented here. On a shoestring budget, a team of amateurs hit a target the size of two soccer fields with an autonomous aircraft from a range of almost 200 kilometers. That’s why we’re impressed, and we can’t wait to see what they can do after a release from the edge of space.

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Radiosondes: Getting Data from Upstairs

Ever since I first learned about radiosondes as a kid, I’ve been fascinated by them. To my young mind, the idea that weather bureaus around the world would routinely loft instrument-laden packages high into the atmosphere to measure temperature, pressure, and winds aloft seemed extravagant. And the idea that this telemetry package, having traveled halfway or more to space, could crash land in a field near my house so that I could recover it and take it apart, was an intoxicating thought.

I’ve spent a lot of time in the woods over the intervening years, but I’ve never seen a radiosonde in the wild. The closest I ever came was finding a balloon with a note saying it had been released by a bunch of schoolkids in Indiana. I was in Connecticut at the time, so that was pretty cool, but those shortsighted kids hadn’t put any electronics on their balloon, and they kind of left me hanging. So here’s a look at what radiosondes are, how they work, and what you can do to increase your chances of finding one.

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Ham Antenna Rises to the Occasion

There was a time when you could do what you wanted in your yard and hams could build giant antenna farms. These days, there are usually laws or deed restrictions that stop that from happening. Even if you can build an antenna, you might want to quickly put up something temporary in an emergency.

[Eric’s] solution? Suspend a wire from a weather balloon filled with helium from the local WalMart. The 8 foot balloon took two containers (18 cubic feet) of gas before it would rise sufficiently. Once you have a floating balloon, the rest of the concept is simple: connect a wire (100 feet of 26 gauge), use a tuner to match the load to the transmitter, and you have instant antenna.

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The Dubious Claim of a World Helium Shortage

If you’ve been reading the news lately, you doubtless read about the find of a really big new helium gas field in Tanzania. It’s being touted as “life-saving” and “game-changing” in the popular media, but this is all spin. Helium is important for balloon animals, scientists, and MRI machines alike, but while it’s certainly true that helium prices have been rising steadily since 2000, this new field is unlikely to matter all that much in the grand scheme of things.

Source: USGS

The foundation of every news story on helium is that we’re running out of the stuff. As with most doomsday scenarios, the end of the world’s supply of helium is overstated, and we don’t just mean in light of the new Tanzanian field. Helium is the second-most abundant element, making up 24% of the total mass of the universe. And while the earth has a disproportionate amount of heavier elements, helium is in rocks everywhere. It’s just a question of getting it out, and at what price that’s viable.

So while we’re stoked that the era of (relatively) cheap helium can continue onwards for a few more years, we’re still pretty certain that the price is going to continue to rise, and our children’s children won’t be using the stuff for something so frivolous as blowing up party balloons — it’ll be used primarily, as it is now, where it’s more valuable: in science, medicine, and industry.

Let’s take this moment to reflect on the economics of second-lightest element. Here’s to you, Helium!

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Retrotechtacular: First laser transmitter built 50 years ago


Most of the time we feature hokey film footage in our Retrotechtacular series, but we think this hack is as cool today as it was fifty years ago. [Clint] wrote in to tell us about Operation Red Line. It was an experiment performed May 3rd and 4th, 1963, which means the 50th anniversary just passed a few weeks ago. The hack involved sending data (audio in this case) over long distances using a laser. But back then you couldn’t just jump on eBay and order up the parts. The team had to hack together everything for themselves.

They built their own helium-neon laser tube, which is shown on the right. The gentlemen involved were engineers at a company called Electro-Optical System (EOS) by day, and Ham radio enthusiasts by night. With the blessing of their employer they were able to ply their hobby skills using the glass blowing and optical resources from their work to get the laser up and running. With that side of things taken care of they turned to the receiving end. Using a telescope and a photomultipler they were able to pick up the beam of light at a distance of about 119 miles. The pinnacle of their achievement was modulating audio on the transmitter, and demodulating it with the receiver.

[Clint] knows the guys who did this and wrote up a look back at the project on his own blog.

New dirigibles are power plants in the sky

We wonder if a floating wind turbine generator (translated) like this one would alleviate some of the complaints we hear about ground-based turbines. This huge helium-filled structure is designed to generate electricity at high altitude, where winds are stronger and blow much more consistently than near ground level. We’ve read complaints at the unsightliness of wind farms, and the noise that they make as the turbines spin. A test run took place at only 350 feet, but this generator is meant to fly at an altitude of 2000 feet. We’d bet it’s much less obtrusive and much quieter at that distance.

There isn’t a whole lot to the lighter-than-air assembly. It’s got an aerodynamic balloon with stabilizing fins, and a propeller attached to a generator at the center. The tether that holds it in place also carries the conductors which translate the power down to the ground. There is mention of a fail-safe system that allows for a slow descent if it get gets away from its tether, so you shouldn’t have to worry about the sky falling on you.

It’s certainly an interesting idea. For some reason this makes us think of the space-based solar generator panels found on Larry Niven’s Ringworld.

[via Reddit]

High Voltage Hacks: Transmute the elements in your garage

The magnum opus of alchemy was the Philosopher’s stone, a substance that was able to turn common metals into gold. Unlike alchemists, [Carl Willis] might not be poisoning himself in a multitude of ways, but he did build a Farnsworth fusor that’s capable of turning Hydrogen into Helium.

To fuse Hydrogen in his device, [Carl] first evacuates a vacuum chamber. Deuterium (Hydrogen with an added neutron) is injected into the chamber, and a spherical cathode made of Tungsten is charged to 75 kV. The deuterium gas is heated and confined by the cathode and fuses into Helum. The electrostatic confinement of the plasma isn’t very much different from some old CRT tubes. This isn’t a coincidence – both the fusor and CRTs were invented by the same man.

While no fusion experiments – including some billion dollar experiments – have ever produced a net energy gain, this doesn’t mean it’s not an impressive engineering feat. If you’d like to try your hand at building your own fusor, drop by the surprisingly active research forum. There’s a lot of really good projects to look through over there.