Sharkskin Coating Reduces Airliner Fuel Use, Emissions

The aviation industry is always seeking advancements to improve efficiency and reduce carbon emissions. The former is due to the never-ending quest for profit, while the latter helps airlines maintain their social license to operate. Less cynically, more efficient technologies are better for the environment, too.

One of the latest innovations in this space is a new sharkskin-like film applied to airliners to help cut drag. Inspired by nature itself, it’s a surface treatment technology that mimics the unique characteristics of sharkskin to enhance aircraft efficiency. Even better, it’s already in commercial service! Continue reading “Sharkskin Coating Reduces Airliner Fuel Use, Emissions”

Robot 3D Prints Giant Metal Parts With Induction Heat

While our desktop machines are largely limited to various types of plastic, 3D printing in other materials offers unique benefits. For example, printing with concrete makes it possible to quickly build houses, and we’ve even seen things like sugar laid down layer by layer into edible prints. Metals are often challenging to print with due to its high melting temperatures, though, and while this has often been solved with lasers a new method uses induction heating to deposit the metals instead.

A company in Arizona called Rosotics has developed a large-scale printer based on this this method that they’re calling the Mantis. It uses three robotic arms to lay down metal prints of remarkable size, around eight meters wide and six meters tall. It can churn through about 50 kg of metal per hour, and can be run off of a standard 240 V outlet. The company is focusing on aerospace applications, with rendered rocket components that remind us of what Relativity Space is working on.

Nothing inspires confidence like a low-quality render.

The induction heating method for the feedstock not only means they can avoid using power-hungry and complex lasers to sinter powdered metal, a material expensive in its own right, but they can use more common metal wire feedstock instead. In addition to being cheaper and easier to work with, wire is also safer. Rosotics points out that some materials used in traditional laser sintering, such as powdered titanium, are actually explosive.

Of course, the elephant in the room is that Relativity recently launched a 33 meter (110 foot) tall 3D printed rocket over the Kármán line — while Rosotics hasn’t even provided a picture of what a component printed with their technology looks like. Rather than being open about their position in the market, the quotes from CEO Christian LaRosa make it seem like he’s blissfully unaware his fledgling company is already on the back foot.

If you’ve got some rocket propellant tanks you’d like printed, the company says they’ll start taking orders in October. Though you’ll need to come up with a $95,000 deposit before they’ll start the work. If you’re looking for something a little more affordable, it’s possible to convert a MIG welder into a rudimentary metal 3D printer instead.

Magnesium: Where It Comes From And Why We’re Running Out

Okay, we’re not running out. We actually have tons of the stuff. But there is a global supply chain crisis. Most of the world’s magnesium is processed in China and several months ago, they just… stopped. In an effort to hit energy consumption quotas, the government of the city of Yulin (where most of the country’s magnesium production takes place) ordered 70% of the smelters to shut down entirely, and the remainder to slash their output by 50%. So, while magnesium remains one of the most abundant elements on the planet, we’re readily running out of processed metal that we can use in manufacturing.

Nikon camera body
The magnesium-alloy body of a Nikon d850. Courtesy of Nikon

But, how do we actually use magnesium in manufacturing anyway? Well, some things are just made from it. It can be mixed with other elements to be made into strong, lightweight alloys that are readily machined and cast. These alloys make up all manner of stuff from race car wheels to camera bodies (and the chassis of the laptop I’m typing this article on). These more direct uses aside, there’s another, larger draw for magnesium that isn’t immediately apparent: aluminum production.

But wait, aluminum, like magnesium is an element. So why would we need magnesium to make it? Rest assured, there’s no alchemy involved- just alloying. Much like magnesium, aluminum is rarely used in its raw form — it’s mixed with other elements to give it desirable properties such as high strength, ductility, toughness, etc. And, as you may have already guessed, most of these alloys require magnesium. Now we’re beginning to paint a larger, scarier picture (and we just missed Halloween!) — a disruption to the world’s aluminum supply.

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Image of detonation engine firing

Japanese Rocket Engine Explodes: Continuously And On Purpose

Liquid-fuelled rocket engine design has largely followed a simple template since the development of the German V-2 rocket in the middle of World War 2. Propellant and oxidizer are mixed in a combustion chamber, creating a mixture of hot gases at high pressure that very much wish to leave out the back of the rocket, generating thrust.

However, the Japan Aerospace Exploration Agency (JAXA) has recently completed a successful test of a different type of rocket, known as a rotating detonation engine. The engine relies on an entirely different method of combustion, with the aim to produce more thrust from less fuel. We’ll dive into how it works, and how the Japanese test bodes for the future of this technology.

Deflagration vs. Detonation

Humans love combusting fuels in order to do useful work. Thus far in our history, whether we look at steam engines, gasoline engines, or even rocket engines, all these technologies have had one thing in common: they all rely on fuel that burns in a deflagration. It’s the easily controlled manner of slow combustion that we’re all familiar with since we started sitting around campfires. Continue reading “Japanese Rocket Engine Explodes: Continuously And On Purpose”

Let’s Take A Closer Look At This Robotic Airship

It’s not a balloon, however shiny its exterior may seem. This miniature indoor robotic airship created by the University of Auckland mechanical engineering research group [New Dexterity] is an asymmetric system experimenting with the possibilities of an open-source helium-based airship.

Why a helium airship, as opposed to a fixed wing aircraft? The group wanted to experiment with the advantages of lighter-than-air (LTA) travel, namely the higher mobility and looser path planning constraints. Furthermore, LTA airships have a less obstructed field of vision and fewer locomotion issues. While unmanned aerial vehicles (UAV) may be capable of hovering in one place, their lift is generated by rotor thrust, which drains their batteries quickly in the order of minutes. LTA airships can hover for longer periods of time.

The design was created for educational and research purposes, focusing on the financial feasibility of manufacturing the platform, the environmental impact of the materials, and the helium loss through the balloon-like envelope. By measuring these parameters, the researchers are able to study the effects of circumstances such as the cost of indoor commercial balloons and the mechanical properties of balloon materials.

The airship gondola was designed and 3D printed in a modular fashion, then attached to the envelope with Velcro. The placement with respect to the horizontal symmetry of the gondola was done for flight stability, with several configurations tested for the side rotor angle.

The group open-sourced their CAD files and ROS interface for controlling the airship. They primarily use off-the-shelf components such as Raspberry Pi boards, propellers, a DC single brushed motor driver carrier, and LiPo batteries for a total cost of $90 for the platform, with an addition $20 for the balloon and initial helium filling. The price is comparable to the cost of indoor blimps like the Blimpduino 2.0.

You can check out the completed airship below, where the team demonstrates its path following capabilities based on a carrot chasing path finding algorithm. And if you’re interested in learning more about the gotchas of building lighter-than-air vehicles, check out [Sophi Kravitz’s] blimp talk from Hackaday Belgrade.

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Developing Guidelines For Sustainable Spaceflight

In the early days of spaceflight, when only the governments of the United States and the Soviet Union had the ability to put an object into orbit, even the most fanciful of futurists would have had a hard time believing that commercial entities would one day be launching sixty satellites at a time. What once seemed like an infinite expanse above our heads is now starting to look quite a bit smaller, and it’s only going to get more crowded as time goes on. SpaceX is gearing up to launch nearly 12,000 individual satellites for their Starlink network by the mid-2020s, and that’s just one of the “mega constellations” currently in the works.

Just some of the objects in orbit around the Earth

It might seem like overcrowding of Earth orbit is a concern for the distant future, but one needs only look at recent events to see the first hints of trouble. On September 2nd, the European Space Agency announced that one of its research spacecraft had to perform an evasive maneuver due to a higher than acceptable risk of colliding with one of the first-generation Starlink satellites. Just two weeks later, Bigelow Aerospace were informed by the United States Air Force that there was a 1 in 20 chance that a defunct Russian Cosmos 1300 satellite would strike their Genesis II space station prototype.

A collision between two satellites in orbit is almost certain to be catastrophic, ending with both spacecraft either completely destroyed or severely damaged. But in the worst case, the relative velocity between the vehicles can be so great that the impact generates thousands of individual fragments. The resulting cloud of shrapnel can circle the Earth for years or even decades, threatening to tear apart any spacecraft unlucky enough to pass by.

Fortunately avoiding these collisions shouldn’t be difficult, assuming everyone can get on the same page before it’s too late. The recently formed Space Safety Coalition (SSC) is made up of more than twenty aerospace companies that realize the importance of taking proactive steps to ensure humanity retains the unfettered access to outer space by establishing some common “Rules of the Road” for future spacecraft.

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Hey NASA, Do You Want Your Stuff Back?

What would you do if you found hidden away artifacts of aerospace technology from the Apollo era?

You call NASA.

Two hulking computers — likely necessitating the use of a crane to move them — and hundreds of tape reels were discovered in the basement of a former IBM engineer by their heir and a scrap dealer cleaning out the deceased’s home. Labels are scarce, and those that are marked are mostly from the late 1960s through the mid 1970s, including data from the Pioneer 8 to 11 missions, as well as the Helios missions.

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