A SpaceX Falcon 9 Will Blow Up Very Soon, And That’s OK

January 16, 2020 by Tom Nardi 27 Comments

They say you can’t make an omelette without breaking a few eggs, and there are few fields where this idiom is better exemplified than rocketry. It’s a forgone conclusion that when you develop a new booster, at least a few test articles are going to be destroyed in the process. In fact, some argue that a program that doesn’t push the hardware to the breaking point is a program that’s not testing aggressively enough.

Which is why, assuming everything goes according to plan, SpaceX will be obliterating one of their Falcon 9 boosters a little after 8:00 AM EST on Saturday morning. The event will be broadcast live via the Internet, and thanks to the roughly 70% propellant load it will be carrying at the moment of its destruction, it should prove to be quite a show.

This might seem like an odd way to spend $62 million, but for SpaceX, it’s worth it to know that the Crew Dragon Launch Abort System (LES) will work under actual flight conditions. The LES has already been successfully tested once, but that was on the ground and from a standstill. It allowed engineers to see how the system would behave should an abort occur while the rocket was still on the pad, but as the loss of the Soyuz MS-10 dramatically demonstrated, astronauts may need to make a timely exit from a rocket that’s already well on the way to space.

In an actual emergency, the crewed spacecraft will very likely be speeding away from a violent explosion and rapidly expanding cloud of shrapnel. The complete destruction of the Falcon 9 that will be carrying the Crew Dragon during Saturday’s test will serve to create the same sort of conditions the spacecraft will need to survive if the LES has any hope of bringing the crew home safely. So even if there was some way to prevent the booster from breaking up during the test, it’s more useful from an engineering standpoint to destroy it.

Of course, that only explains why the Falcon 9 will be destroyed during this test. But exactly how this properly functioning booster will find itself being ripped to pieces high over the Atlantic Ocean in a matter of seconds is an equally interesting question.

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Automate Your Life With Node-RED (Plus A Dash Of MQTT)

January 15, 2020 by Mike Szczys 54 Comments

For years we’ve seen a trickle of really interesting home automation projects that use the Node-RED package. Each time, the hackers behind these projects have raved about Node-RED and now I’ve joined those ranks as well.

This graphic-based coding platform lets you quickly put together useful operations and graphic user interfaces (GUIs), whether you’re the freshest greenhorn or a seasoned veteran. You can use it to switch your internet-connected lights on schedule, or at the touch of a button through a web-app available to any device on your home network. You can use it as an information dashboard for the weather forecast, latest Hackaday articles, bus schedules, or all of them at once. At a glance it abstracts away the complexity of writing Javascript, while also making it simple to dive under hood and use your 1337 haxor skills to add your own code.

You can get this up and running in less than an hour and I’m going to tackle that as well as examples for playing with MQTT, setting up a web GUI, and writing to log files. To make Node-RED persistent on your network you need a server, but it’s lean enough to run from a Raspberry Pi without issue, and it’s even installed by default in BeagleBone distributions. Code for all examples in this guide can be found in the tutorial repository. Let’s dive in!

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Tetraethyl Lead: The Solution To One, And Cause Of Many New Problems

January 15, 2020 by Maya Posch 101 Comments

From the 1920s until the 1970s, most gasoline cars in the USA were using fuel that had lead mixed into it. The reason for this was to reduce the engine knocking effect from abnormal combustion in internal combustion engines of the time. While lead — in the form of tetraethyllead — was effective at this, even the 1920s saw both the existence of alternative antiknock agents and an uncomfortable awareness of the health implications of lead exposure.

We’ll look at what drove the adoption of tetraethyllead, and why it was phased out once the environmental and health-related issues came into focus. But what about its antiknock effects? We’ll also be looking at the alternative antiknock agents that took its place and how this engine knocking issue is handled these days.

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A Vintage Phone In 2020

January 14, 2020 by Jenny List 72 Comments

When we make a telephone call in 2020 it is most likely to be made using a smartphone over a cellular or IP-based connection rather than a traditional instrument on a pair of copper wires to an exchange. As we move inexorably towards a wireless world in which the telephone line serves only as a vehicle for broadband Internet, it’s easy to forget the last hundred years or more of telephone technology that led up to the present.

The iconic British telephone of the 1960s and 1970s, the GPO model 746. Mine is from 1971. (That isn’t my phone number)

In a manner of speaking though, your telephone wall socket hasn’t forgotten. If you like old phones, you can still have one, and picture yourself in a 1950s movie as you twirl the handset cord round your finger while you speak. Continue reading “A Vintage Phone In 2020” →

Raspberry Pi 4 And The State Of Video Game Emulation

January 14, 2020 by Drew Littrell 40 Comments

The modern ideal of pixel art is a fallacy. Videogame art crammed onto cartridges and floppy discs were beholden to the CRT display technology of their day. Transmitting analog video within the confines of dingy yellow-RCA-connector-blur, the images were really just a suggestion of on-screen shapes rather than clearly defined graphics. Even when using the superior RGB-video-over-SCART cables, most consumer grade CRT televisions never generated more than about 400 lines, so the exacting nature of digitized plots became a fuzzy raster when traced by an electron beam. It wasn’t until the late 90s when the confluence of high resolution PC monitors, file sharing, and open source emulation software that the masses saw pixels for the sharp square blocks of color that they are.

More importantly, emulation software is not restricted to any one type of display technology any more than the strata of device it runs on. The open-source nature of videogame emulators always seems to congregate around the Lowest Common Denominator of devices, giving the widest swath of gamers the chance to play. Now, that “L.C.D.” may very well be the Raspberry Pi 4. The single board computer’s mix of tinker-friendly IO at an astonishingly affordable entry price has made it a natural home for emulators, but at fifty bucks what options unlock within the emulation scene?

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Anti-Bacterial Plastic Wrap Clings To Hope Of Stopping Superbugs’ Spread

January 13, 2020 by Kristina Panos 45 Comments

Researchers at McMaster University in Ontario have developed a plastic wrap that repels viruses and bacteria, including some of the scariest antibiotic-resistant superbugs known to science. With the help of a scanning electron microscope, the researchers were able to watch superbugs like MRSA and Pseudomonas bounce right off the surface.

The wrap can be applied to things temporarily, much like that stuff you wrestle from the box and stretch over your leftovers. It can also be shrink-wrapped to any compatible surface without losing effectiveness. The ability to cover surfaces with bacteria-shielding armor could have an incredible impact on superbug populations inside hospitals. It could be shrink-wrapped to all kinds of things, from door handles to railings to waiting room chair armrests to the pens that everyone uses to sign off on receiving care.

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Why Do Resistors Have A Color Code?

January 13, 2020 by Al Williams 226 Comments

One of the first things you learn in electronics is how to identify a resistor’s value. Through-hole resistors have color codes, and that’s generally where beginners begin. But why are they marked like this? Like red stop signs and yellow lines down the middle of the road, it just seems like it has always been that way when, in fact, it hasn’t.

Before the 1920s, components were marked any old way the manufacturer felt like marking them. Then in 1924, 50 radio manufacturers in Chicago formed a trade group. The idea was to share patents among the members. Almost immediately the name changed from “Associated Radio Manufacturers” to the “Radio Manufacturer’s Association” or RMA. There would be several more name changes over the years until finally, it became the EIA or the Electronic Industries Alliance. The EIA doesn’t actually exist anymore. It exploded into several specific divisions, but that’s another story.

This is the tale of how color bands made their way onto every through-hole resistor from every manufacturer in the world.

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