Off-World Cement Tested For The First Time

September 30, 2019 by Tom Nardi 54 Comments

If the current Administration of the United States has their way, humans will return to the surface of the Moon far sooner than many had expected. But even if NASA can’t meet the aggressive timeline they’ve been given by the White House, it seems inevitable that there will be fresh boot prints on the lunar surface within the coming decades. Between commercial operators and international competition, we’re seeing the dawn of a New Space Race, with the ultimate goal being the long-term habitation of our nearest celestial neighbor.

Schmitt's dusty suit while retrieving samples from the Moon — An Apollo astronaut covered in lunar dust

But even with modern technology, it won’t be easy, and it certainly won’t be cheap. While commercial companies such as SpaceX have significantly reduced the cost of delivering payloads to the Moon, we’ll still need every advantage to ensure the economical viability of a lunar outpost. One approach is in situ resource utilization, where instead of transporting everything from Earth, locally sourced materials are used wherever possible. This technique would not only be useful on the Moon, but many believe it will be absolutely necessary if we’re to have any chance of sending a human mission to Mars.

One of the most interesting applications of this concept is the creation of a building material from the lunar regolith. Roughly analogous to soil here on Earth, regolith is a powdery substance made up of grains of rock and micrometeoroid fragments, and contains silicon, calcium, and iron. Mixed with water, or in some proposals sulfur, it’s believed the resulting concrete-like material could be used in much the same way it is here on Earth. Building dwellings in-place with this “lunarcrete” would be faster, cheaper, and easier than building a comparable structure on Earth and transporting it to the lunar surface.

Now, thanks to recent research performed aboard the International Space Station, we have a much better idea of what to expect when those first batches of locally-sourced concrete are mixed up on the Moon or Mars. Of course, like most things related to spaceflight, the reality has proved to be a bit more complex than expected.

Continue reading “Off-World Cement Tested For The First Time” →

What On Earth Is A Pickle Fork And Why Is It Adding To Boeing’s 737 Woes?

September 30, 2019 by Jenny List 89 Comments

It’s fair to say that 2019 has not been a good year for the aircraft manufacturer Boeing, as its new 737 MAX aircraft has been revealed to contain a software fault that could cause the aircraft to enter a dive and crash. Now stories are circulating of another issue with the 737, some of the so-called “Pickle forks” in the earlier 737NG aircraft have been found to develop cracks.

It’s a concerning story and there are myriad theories surrounding its origin but it should also have a reassuring angle: the painstaking system of maintenance checks that underpins the aviation industry has worked as intended. This problem has been identified before any catastrophic failures have occurred. It’s not the story Boeing needs at the moment, but they and the regulators will no doubt be working hard to produce a new design and ensure that it is fitted to aircraft.

The Role of the Pickle Fork

For those of us who do not work in aviation though it presents a question: what on earth is a pickle fork? The coverage of the story tells us it’s something to do with attaching the wing to the fuselage, but without a handy 737 to open up and take a look at we’re none the wiser.

Fortunately there’s a comprehensive description of one along with a review of wing attachment technologies from Boeing themselves, and it can be found in one of their patents. US9399508B2 is concerned with an active suspension system for wing-fuselage mounts and is a fascinating read in itself, but the part we are concerned with is a description of existing wing fixtures on page 12 of the patent PDF.

A cross-section of the aircraft wing fixing, in which we've highlighted the role of the pickle forks. (Boeing) — A cross-section of the aircraft wing fixing, in which we’ve highlighted the role of the pickle forks. (Boeing)

The pickle fork is an assembly so named because of its resemblance to the kitchen utensil, which attaches firmly to each side of the fuselage and has two prongs that extend below it where they are attached to the wing spar.

For the curious engineer with no aviation experience the question is further answered by the patent’s figure 2, which provides a handy cross-section. The other wing attachment they discuss involves the use of pins, leading to the point of the patented invention. Conventional wing fixings transmit the forces from the wing to the fuselage as a rigid unit, requiring the fuselage to be substantial enough to handle those forces and presenting a problem for designers of larger aircraft. The active suspension system is designed to mitigate this, and we’d be fascinated to hear from any readers in the comments who might be able to tell us more.

We think it’s empowering that a science-minded general public can look more deeply at a component singled out in a news report by digging into the explanation in the Boeing patent. We don’t envy the Boeing engineers in their task as they work to produce a replacement, and we hope to hear of their solution as it appears.

[via Hacker News]

[Header image: AMX Boeing 737 XA-PAM by Jean-Philippe Boulet CC-BY 3.0]

Gatwick Drone Incident: Police Still Clueless

September 27, 2019 by Jenny List 32 Comments

Quietly released and speedily buried by Parliamentary wrangles over Brexit is the news that Sussex Police have exhausted all lines of inquiry into the widely publicised drone sighting reports that caused London’s Gatwick Airport to be closed for several days last December. The county’s rozzers have ruled out 96 ‘people of interest’ and combed through 129 separate reports of drone activity, but admit that they are no closer to feeling any miscreant collars. There is no mention of either their claims at the time to have found drone wreckage, their earlier admissions that sightings might have been of police drones, or even that there might have been no drone involved at all.

Regular readers will know that we have reported extensively the sorry saga of official reactions to drone incidents, because we believe that major failings in reporting and investigation will accumulate to have an adverse effect on those many people in our community who fly multi-rotors. In today’s BBC report for example there is the assertion that 109 of the drone sightings came from “‘credible witnesses’ including a pilot and airport police” which while it sounds reassuring is we believe a dangerous route to follow because it implies that the quality of evidence is less important than its source. It is crucial to understand that multi-rotors are still a technology with which the vast majority of the population are still unfamiliar, and simply because a witness is a police officer or a pilot does not make them a drone expert whose evidence is above scrutiny.

Whichever stand you take on the drone sightings at Gatwick and in other places it is clear that Sussex Police do not emerge from this smelling of roses and that their investigation has been chaotic and inept from the start. We believe that there should be a public inquiry into the whole mess, so that those embarrassing parts of it which they and other agencies are so anxious to quietly forget can be subjected to scrutiny. We do not however expect this to happen any time soon.

Keystone Kops header image: Mack Sennett Studios [Public domain].

The Future Of Diesel Is On Shaky Ground

September 26, 2019 by Lewin Day 251 Comments

Diesel is a fuel that has had a mixed history, with varying levels of take-up by consumers around the world. In the world of transport, diesel engines have offered better fuel economy and torque than comparable gasoline engines. Particularly popular in Europe, diesel established a strong consumer base in both small commuter cars as well as heavy vehicles such as trucks and buses.

Despite this, the tide is turning, and for the average motorist, diesel’s days may be numbered. Why is this the case, and what are the potential alternatives vying for diesel’s crown?

Plenty of Pros, but Plenty of Cons

Diesel remains a fuel with a varied uptake around the world. It has enjoyed great popularity in Europe in small commuter cars.

Diesel is a hydrocarbon fuel with several advantages over gasoline. Its lack of volatility makes it workable to use in a compression-ignition mode, and diesel engines can be run with lean fuel-air ratios. It also has a higher volumetric energy density than gasoline, and thanks to low volatility, diesel engines can run at significantly higher compression ratios without risking detonation. These benefits allow diesel engines to produce significantly more torque than similarly sized gasoline engines, and they can offer fuel economy gains in excess of 15%.

Unfortunately, diesel also comes with its fair share of drawbacks. Diesel engines are typically poor when it comes to power to weight ratio, as their high compression ratio and torque output demands heavier materials in their construction. The major bugbear of the diesel engine, however, is its emissions. Despite greater fuel efficiency, carbon dioxide output from a diesel engine is often far worse than that of a comparable gas motor. Additionally, their lean-burning nature leads to production of high levels of oxides of nitrogen (NOx), which have major negative environmental effects. There’s also the problem of particulate pollution, which is responsible for respiratory harm in humans. Diesel automobiles rank significantly worse than gasoline vehicles in all these areas. It’s begun to cause figurative headaches for the industry, and literal headaches for the public. Continue reading “The Future Of Diesel Is On Shaky Ground” →

100 Year Old Atomic Clock

September 25, 2019 by Gregory L. Charvat 33 Comments

Precision time is ubiquitous today thanks to GPS and WWVB. Even your Macbook or smartphone displays time which is synchronized to the NIST-F1 clock, a cesium fountain atomic clock (aka the ‘Atomic Clock’) that is part of a global consortium of atomic clocks known as Coordinated Universal Time (UTC). Without precise timing there would be train collisions, markets would tumble, schools would not start on time, and planes would fall out of the sky.

But how was precision timing achieved in the 19th century during the era of steam, brass, and solenoids? One of the first systems of precision timing kept trains running safely and on time, rang the bells at school, and kept markets trading by using a special clock designed by the Self Winding Clock Company. Through measurements of celestial objects by the US Naval Observatory, and time synchronization pulses broadcast by the Western Union telegraph network, this system synchronized time across the United States in an era where the speed of our train system was out-pacing by the precision of our clocks.

Those clocks were designed so well that many of them are still around and functioning. One of these 100-year-old self-winding clocks made its way onto my workbench. I did what any curious hacker would do, figured out how the synchronization worked and connected it to a clock source with atomic precision. Let’s take a look!

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Ask Hackaday: What Good Is A Robot Dog?

September 25, 2019 by Dan Maloney 63 Comments

It is said that Benjamin Franklin, while watching the first manned flight of a hot air balloon by the Montgolfier brothers in Paris in 1783, responded when questioned as to the practical value of such a thing, “Of what practical use is a new-born baby?” Dr. Franklin certainly had a knack for getting to the heart of an issue.

Much the same can be said for Spot, the extremely videogenic dog-like robot that Boston Dynamics has been teasing for years. It appears that the wait for a production version of the robot is at least partially over, and that Spot (once known as Spot Mini) will soon be available for purchase by “select partners” who “have a compelling use case or a development team that [Boston Dynamics] believe can do something really interesting with the robot,” according to VP of business development Michael Perry.

The qualification of potential purchasers will certainly limit the pool of early adopters, as will the price tag, which is said to be as much as a new car – and a nice one. So it’s not likely that one will show up in a YouTube teardown video soon, so until the day that Dave Jones manages to find one in his magic Australian dumpster, we’ll have to entertain ourselves by trying to answer a simple question: Of what practical use is a robotic dog?

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Who Could Possibly Need An FPGA With 9M Logic Cells And 35B Transistors?

September 24, 2019 by Al Williams 101 Comments

Xilinx recently announced the Virtex UltraScale+ VU19P FPGA. Of course, FPGA companies announce new chips every day. The reason this one caught our attention is the size of it: nearly 9 million logic cells and 35 billion transistors on a chip! If that’s not enough there is also over 2,000 user I/Os including transceivers that can move around 4.5 Tb/s back and forth.

To put things in perspective, the previous record holder — the Virtex Ultrascale 440 — has 5.5 million logic cells and an old-fashioned Spartan 3 topped out at about 50,000 cells — the new chip has about 180 times that capacity. For the record, I’ve built entire 32-bit CPUs on smaller Spartans.

That led us to wonder? Who’s buying these things? When I first heard about it I guessed that the price would be astronomical, partly due to expense but also partly because the market for these has to be pretty small. The previous biggest Xilinx part is listed on DigKey who pegs the Ultrascale 440 (an XCVU440-2FLGA2892E) at a cost of $55,000 as a non-stocked item. Remember, that chip has just over half the logic cells of the VU19P.

Continue reading “Who Could Possibly Need An FPGA With 9M Logic Cells And 35B Transistors?” →