See Starlink’s “Space Train” Before It Leaves The Station

Have you looked up into the night sky recently and seen a bizarre line of luminous dots? Have you noticed an uptick in the number of UFO reports mentioned in the news and social media? If so, you may have already been touched by what many have come to affectionately call Elon Musk’s “Space Train”: a line of tightly grouped Starlink satellites that are making their way around the globe.

Some have wondered what’s so unique about the Starlink satellites that allows them to be visible from the ground by the naked eye, but that’s actually nothing new. It’s all about being in the right place at the right time, for both the observer¬†and the spacecraft in question. The trick is having the object in space catch the light from the Sun when it has, from the observer’s point of view, already set. It’s essentially the same reason the Moon shines at night, but on a far smaller scale.

The ISS as it travels through Earth’s night and day

The phenomena is known as “satellite flare”, and chasing them is a favorite pastime of avid sky watchers. If you know when and where to look on a clear night, you can easily spot the International Space Station as it zips across the sky thanks to this principle. NASA even offers a service which uses email or SMS to tell you when the ISS should be visible from your location.

What makes the Starlink satellites unique isn’t that we can see them from the ground, but that there’s so many of them flying in a straight line. The initial launch released 60 satellites in a far tighter formation than we’ve ever seen before; Elon even warned that collisions between the individual Starlink satellites wasn’t out of the realm of possibility. The cumulative effect of these close proximity satellite flares is a bit startling, and understandably has people concerned about what the night sky might look like when all 12,000 Starlink satellites are in orbit.

The good news is, the effect is only temporary. As the satellites spread out and begin individual maneuvers, that long line in the sky will fade away. But before Elon’s “Space Train” departs for good, let’s look at how it was created, and how you can still catch a glimpse of this unique phenomena.

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The Fascinating World Of Solder Alloys And Metallurgy

Solder is the conductive metal glue that one uses to stick components together. If you get the component and the PCB hot enough, and melt a little solder in the joint, it will stay put and conduct reliably. But it’s far from simple.

There are many different solder alloys, and even the tip of the soldering iron itself is a multi-material masterpiece. In this article, we’ll take a look at the metallurgy behind soldering, and you’ll see why soldering tip maintenance, and regular replacement, is a good idea. Naturally, we’ll also touch upon the role that lead plays in solder alloys, and what the effect is of replacing it with other metals when going lead-free. What are you soldering with? Continue reading “The Fascinating World Of Solder Alloys And Metallurgy”

Atomic Power Gets Small

There was a time when nuclear power plants were going to save the world. Barring accidents, the plants are clean and generate a lot of power. However, a few high-profile accidents and increased public awareness of some key issues have made nuclear power a hard sell, at least in the United States. The fastest growing nuclear power-related business in the US — according to sources — is companies decommissioning nuclear power plants. However, there’s a move afoot to make nuclear power a viable solution again. The company behind it says their plants will be cheaper to build, cheaper to operate, and are much safer than conventional plants. Are those claims reasonable?

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There And Back Again: A Falcon 9 Launch Story

It’s true that I’m not known for keeping particularly regular hours, but even I had my doubts about this plan. We’d go to sleep around midnight, wake up at 3 AM, drive up the coast aimlessly, then turn around and attend a full-day event where we’d have to maintain at least some semblance of professionalism. It was a bad idea, terrible even. But there I was at 11:30 PM sitting in a Waffle House with Thomas, the Supplyframe videographer, getting dangerously close to signing off on it.

Officially we were there to cover the Cornell Cup Finals being held at Kennedy Space Center, but as it so happens, our arrival in Florida perfectly coincided with the launch of CRS-17, SpaceX’s latest International Space Station resupply mission. Technically this was not part of our assignment. But really, what choice did we have?

Even if our respective bosses didn’t see it as a wasted opportunity, we had to consider the locals. In the few hours we’d been here, it seemed the launch was all anyone wanted to talk about. Everyone from the airport shuttle driver to the waitress who brought us our hash browns reminded us a rocket would be lifting off soon. If we didn’t go, then come Friday afternoon we’d be the only people in Cape Canaveral who didn’t have a personal account of the event. By all indications, an unforgivable cultural faux pas in central Florida.

Of course, the truth of the matter is that we didn’t actually need any convincing to go on this adventure. We had the supreme good fortune of finding ourselves in the vicinity of Kennedy Space Center a few hours before they were going to send a rocket thundering off into the black, and there was no way we could just sleep through it. No, there was never any choice in the matter. We were going.

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3D Printering: The Past And Future Of Prusa’s Slicer

If you own a desktop 3D printer, you’re almost certainly familiar with Slic3r. Even if the name doesn’t ring a bell, there’s an excellent chance that a program you’ve used to convert STLs into the G-code your printer can understand was using Slic3r behind the scenes in some capacity. While there have been the occasional challengers, Slic3r has remained one of the most widely used open source slicers for the better part of a decade. While some might argue that proprietary slicers have pulled ahead in some respects, it’s hard to beat free.

So when Josef Prusa announced his team’s fork of Slic3r back in 2016, it wasn’t exactly a shock. The company wanted to offer a slicer optimized for their line of 3D printers, and being big proponents of open source, it made sense they would lean heavily on what was already available in the community. The result was the aptly named “Slic3r Prusa Edition”, or as it came to be known, Slic3r PE.

Ostensibly the fork enabled Prusa to fine tune print parameters for their particular machines and implement support for products such as their Multi-Material Upgrade, but it didn’t take long for Prusa’s developers to start fixing and improving core Slic3r functionality. As both projects were released under the GNU Affero General Public License v3.0, any and all of these improvements could be backported to the original Slic3r; but doing so would take considerable time and effort, something that’s always in short supply with community developed projects.

Since Slic3r PE still produced standard G-code that any 3D printer could use, soon people started using it with their non-Prusa printers simply because it had more features. But this served only to further blur the line between the two projects, especially for new users. When issues arose, it could be hard to determine who should take responsibility for it. All the while, the gap between the two projects continued to widen.

With a new release on the horizon that promised to bring massive changes to Slic3r PE, Josef Prusa decided things had reached a tipping point. In a recent blog post, he announced that as of version 2.0, their slicer would henceforth be known as PrusaSlicer. Let’s take a look at this new slicer, and find out what it took to finally separate these two projects.

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Life After IRC – Your Move, Mozilla!

Last year marked the 30th anniversary of the Internet Relay Chat protocol (IRC) and it is hard to imagine that [Jarkko Oikarinen] could have foreseen the impact his invention would one day have on the world as we know it. How it would turn from a simple, decentralized real-time communication system for university-internal use into a global phenomenon, connecting millions of users all over the world, forming its own subculture, eventually reaching mainstream status in some parts of the world — including a Eurodance song about a bot topping European music charts.

Those days of glory, however, have long been gone, and with it the version of an internet where IRC was the ideal choice. What was once a refuge to escape the real world has since become the fundamental centerpiece of that same real world, and our ways of communicating with each other has moved on with it. Nevertheless, despite a shift in mainstream and everyday communication behavior, IRC is still relevant enough today, and going especially strong in the open source community, with freenode, as one of the oldest networks, being the most frequently used one, along some smaller ones like OFTC and Mozilla’s own dedicated network. But that is about to change.

Last month, Mozilla’s envoy [Mike Hoye] announced the decommissioning of irc.mozilla.org within “the next small number of months, and moving all communication to a new, or at least different system. And while this only affects Mozilla’s own, standalone IRC network and projects, and not the entire open source community, it is a rather substantial move, considering Mozilla’s overall reach and impact on the internet itself — past, present, and now even more the future. Let’s face it, IRC has been dying for years, but there is also no genuine alternative available yet that could truly replace it. With Mozilla as driving force, there is an actual chance that they will come up with a worthy replacement that transforms IRC’s spirit into the modern era.

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Zork And The Z-Machine: Bringing The Mainframe To 8-bit Home Computers

Computer games have been around about as long as computers have. And though it may be hard to believe, Zork, a text-based adventure game, was the Fortnite of its time. But Zork is more than that. For portability and size reasons, Zork itself is written in Zork Implementation Language (ZIL), makes heavy use of the brand-new concept of object-oriented programming, and runs on a virtual machine. All this back in 1979. They used every trick in the book to pack as much of the Underground Empire into computers that had only 32 kB of RAM. But more even more than a technological tour de force, Zork is an unmissable milestone in the history of computer gaming. But it didn’t spring up out of nowhere.

DEC PDP-10 Flip Chip module
DEC PDP-10 Flip Chip module

The computer revolution had just taken a fierce hold during the second World War, and showed no sign of subsiding during the 1950s and 1960s. More affordable computer systems were becoming available for purchase by businesses as well as universities. MIT’s Laboratory for Computer Science (LCS) was fortunate to have ties to ARPA, which gave MIT’s LCS and AI labs (formerly part of Project MAC) access to considerable computing resources, mostly in the form of DEC PDP systems.

The result: students at the MIT Dynamic Modeling Group (part of LCS) having access to a PDP-10 KA10 mainframe — heavy iron at the time. Though this PDP-10 was the original 1968 model with discrete transistor Flip Chip modules and wire-wrapping, it had been heavily modified, adding virtual memory and paging support to expand the original 1,152 kB of core memory. Running the MIT-developed Incompatible Timesharing System (ITS) OS, it was a highly capable multi-user system.

Naturally, it got mostly used for playing games.
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