Saving Martian Colonists Using Table Salt And Rocket Science

January 24, 2022 by Ryan Flowers 45 Comments

Imagine for a moment that you are a member of an early Mars colony. You’re stranded, and the only way to get a message home is to launch a radio well above the surface. To make matters worse, you’ve got no rockets! It was this thought experiment that has motivated [Thoisoi2] to experiment with making a rocket motor using only ingredients and methods available to your average Martian colonist. The methods he has chosen can be seen in the video below the break.

If you skipped Rocketry 101, a quick refresher might help: Rockets work by burning a fuel in an enclosed chamber and then expelling it at high speed in one direction. To get the fuel to burn more quickly (and therefore adding more oomph to the angry end) a complement to the fuel called an Oxidizer is added. It serves to create an oxygen rich environment for the fuel to burn in. It’s the same reason a oxy-propane torch burns hotter than propane by itself.

Sugar Fuels Go Boom — The Sugar Powered Rocket Motor says “Boom!”

Firstly, a stranded Martian would need rocket fuel. If you recall the 1999 movie October Sky, four high school kids used table sugar as their fuel. You might also recall that those tended to get all explody. This volatility caused [Thoisoi2] to eschew sugar as a fuel in favor of a fuel that would also be available to any Martian colonist but be far less likely to cause Rapid Unplanned Disassembly.

What about the oxidizer? In October Sky, the boys experimented with Potassium Chlorate. This is commonly used in rockets but may be more difficult to obtain for your average Mars colonist. But, it turns out that Potassium Chlorate and Sodium Chlorate which can be prepared from table salt will work equally. It’s quite a bit more involved than that however.

Simply adding salt and fuel does not a rocket motor make. The nuances, the science, and the chemistry are all laid out in the wonderful video that [Thoisoi2] has put together, and we are sure you’ll enjoy it as much as we did.

You’ll also get to find out if our stranded Martian ever makes it home or if his potato farming was for naught.

We’d also like to echo the warning in the video: This is an experiment that is pretty dangerous, so don’t try this at home! Definitely try it at somebody else’s house first. Or on the surface of Mars.

Recently Hackaday covered another great attempt at making a rocket motor at home, although this one was a bit less successful, but every bit as interesting! Continue reading “Saving Martian Colonists Using Table Salt And Rocket Science” →

Floating Solar Farms Are Taking The World’s Reservoirs By Storm

January 24, 2022 by Zoe Skyforest 60 Comments

Photovoltaic solar panels are wonderful things, capable of capturing mere light and turning it into useful electricity. They’re often installed on residential and commercial rooftops for offsetting energy use at the source.

However, for grid-scale generation, they’re usually deployed in huge farms on tracts of land in areas that receive plenty of direct sunlight. These requirements can often put solar farms in conflict with farm-farms — the sunlight that is good for solar panels is also good for growing plants, specifically those we grow for food.

One of the more interesting ideas, however, is to create solar arrays that float on water. Unlike some of the wackier ideas out there, this one comes with some genuinely interesting engineering benefits, too!

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Detecting Alpha Particles Using Copper Wire And High Voltage

January 22, 2022 by Robin Kearey 14 Comments

If you want to measure radioactivity, nothing really beats a Geiger counter: compact, rugged, and reasonably easy to use, they’re by far the most commonly used tool to detect ionizing radiation. However, several other methods have been used in the past, and while they may not be very practical today, recreating them can make for an interesting experiment.

[Mirko Pavleski] used easily obtainable components to build one such device known as an alpha radiation spark detector. Invented in 1945, a spark detector contains a strong electric field into which discharges are triggered by ionizing radiation. Unlike a Geiger-Müller tube, it uses regular air, which makes it sensitive only to alpha radiation; beta and gamma rays don’t cause enough ionization at ambient pressure. Fortunately, alpha radiation is the main type emitted by the americium tablets found in old smoke detectors, so a usable source shouldn’t be too hard to find.

The construction of this device is very simple: a few thin copper wires are suspended above a round metal can, while a cheap high-voltage source provides a strong electric field between them. Sparks fly from the wires to the can when an alpha source is brought nearby; a series resistor limits the current to ensure the wires don’t overheat and melt.

Although not really practical as a measurement device, the spark detector can nevertheless be used to perform simple experiments with radioactivity. As an example, [Mirko] demonstrates in the video embedded below that alpha particles are stopped by a piece of paper and therefore present no immediate danger to humans. The high voltage present in the device does however, so care must be taken with the detector more than with the radiation source.

We’ve seen several homebrew Geiger counters, some built with plenty of duct tape or with the good old 555 timer. But you can also use photodiodes or even certain types of plastic to visualize ionizing radiation.

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Thirty Seconds At 100 Megakelvins

January 16, 2022 by Chris Lott 28 Comments

Back in Dec 2020 we wrote about the Korea Superconducting Tokamak Advanced Research (KSTAR) magnetic fusion reactor’s record-breaking feat of heating hydrogen plasma up to 100 megakelvins for 20 seconds. Last month it broke its own record, extending that to 30 seconds. The target of the program is 300 seconds by 2026. There is a bit of competition going, as KSTAR’s Chinese partner in the International Thermonuclear Experimental Reactor (ITER), the Experimental Advanced Superconducting Tokamak (EAST) did a run a week later reaching 70 million degrees for 1056 seconds. It should be noted that KSTAR is reaching these temperatures by heating ions in the plasma, while EAST takes a different approach acting on the electrons.

The news reports seem to be using Celsius and Kelvins interchangeably, but at millions of degrees, that’s probably much smaller than measurement error. These various milestones are but stepping stones along the path to create a demonstration large fusion reactor, the goal of the global ITER mega-project. Currently China, the EU including Switzerland and the UK, India, Japan, Russia, South Korea, and the United States are members of ITER, and Australia, Canada, Kazakhstan, and Thailand are participants. The ITER demonstration reactor is being constructed at the Cadarache facility located 60 km northeast of Marseille, France, and is on track for commissioning phase to begin in 2025, going operational ten years later.

Rapid-Reload Vacuum Cannon Totally Demolishes Those Veggies

January 14, 2022 by Dave Rowntree 9 Comments

[NightHawkInLight] has been developing his design for a vacuum canon for a while now, so it seems fitting to drop in check out the progress. The idea is pretty straightforward, take a long rigid tube, insert a close fitting piston, magnetically attached to a projectile, and stopper the open end with something easily destroyed. The piston needs to be pulled into the tube with some force, to pull a vacuum against the stopper. The interesting bit happens next, when the piston exits the other end of the tube, with the vacuum at its maximum, there is a sudden inrush of air. Apparently this inrush of supersonic velocity, and the momentum of the mass of air is sufficient to eject the projectile at considerable velocity, smashing through the plug and demolishing the target. So long as the target is of the soft and squishy variety anyway.

It’s an interesting idea, and certainly gives plenty of bang for not many bucks. That big lump of acrylic tubing (presumably used for ease of explanation in the video) looks fairly expensive to buy off the shelf, but we reckon any old pipe would probably work out fine.

We’ve definitely covered our share of DIY projectile weapons, like this air cannon made from PVC pipe parts, and of course there’s this crazy big one, that you should definitely not try at home.

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This DIY Microscope Design Is All Wet

January 14, 2022 by Al Williams 5 Comments

[Robert Murray-Smith] wanted to recreate how some ancient microscopes worked: with a drop of water as a lens. The idea is that the meniscus of a drop of water will work as a lens. This works because of surface tension and by controlling the attraction of the water to the surface, you can actually form convex and concave surfaces.

What’s interesting is that this doesn’t require a lot of equipment. Some plastic, a hole punch, some pens, a flashlight, and some other odds and ends. Then it’s just a matter of grabbing some puddle water and examining the critters inside. Of course, with a single lens, these are more properly magnifying glasses. Some claim that people in China built such instruments thousands of years ago. [Robert] mentions [Antonie van Leeuwenhoek] as the father of the microscope, although he wasn’t the first to build such a device. He did create amazing glass lenses using a method he kept secret but has been worked out using modern science.

It is hard to see much through the camera, but it clearly was magnifying. Not a bad little rainy day kid’s project since you probably have everything you need on hand. We wonder what other readily-available things you could image with a device like this.

Of course, if you want to build a real microscope, the designs are out there. You can even make one using — mostly — LEGO.

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Illuminating Origami Is Just Around The Corner

January 12, 2022 by Michael Shaub 14 Comments

Pop-up greeting cards are about to get a whole lot more interesting. Researchers at Seoul National University in Korea have created glowing 3D objects with a series of prototypes that fold thin QLED (Quantum Dot LED) sheets like origami. They used a CO₂ laser to etch “fold lines” in the QLED so the sheets could be formed into 3D shapes. The bends are actually rounded, but at 5μm they appear to be sharp corners and the panels continue to illuminate across the fold lines for at least 500 folds. Some glow in solid colors, while others use smaller addressable areas to create animated matrix displays of patterns and letterforms. See the short video after the break, read the Physics World article or to see all the prototypes and dig into details of the full research paper in Nature (freed from the paywall by SharedIt).

Folded QLED Panels – forming a pyramid and a cube

Folded QLED Panels – various patterns and the 3D forms they fold into

We’re not sure how soon this technique can be duplicated in our home labs, but we can’t wait to fold up our own 3D lights and matrices. Until then, check out some glowing origami you can make right now from [Charlyn Gonda] at Remoticon 2020 and earlier that year and this amazing origami lamp.

Continue reading “Illuminating Origami Is Just Around The Corner” →