Continental Europe’s First Spaceport – And It’s Above The Arctic Circle!

November 9, 2023 by 28 Comments

When we think of a space launch it’s likely our minds might turn to the lush swampland of Florida’s Cape Canaveral, or the jungle of Kourou in Guyana. These are both in the tropical regions on sites as close to the Equator as the governments who built them could find, because the higher rotational speed of the planet at its widest point gives departing rockets a bit of extra kick. Even the Soviet Baikonur cosmodrome in modern-day Kazakhstan which sits at around 45 degrees North, was chosen in part to lie in one of the more southerly Soviet republics.

It’s unexpected then to report on the opening of what may at the time of writing be the world’s newest spaceport, situated on the island of Andøya in northern Norway, at around 69 degrees North. Just what is going on?

The answer for the German company Isar Aerospace is that their launches from the site will be ideally placed not for low-inclination orbits but for polar orbits, something of a valuable commodity and a worthy point of competition when compared to equatorial sites. We have shamefacedly to admit that we’re not completely au fait with Norwegian geography, so it took us a minute to find Andøya towards the top of the country’s westward chain of islands.

The spaceport itself lies in a bay facing westward over the Norwegian Sea, and the launch platform is on a stone jetty protruding into the water. It appears to be a beautiful landscape, a suitable reward for any hardy souls who make the trip to watch a launch. Unexpectedly the spaceport stands alone in Continental Europe, though before too long it’s likely to be joined by other projects including one in northern Scotland. European skies are likely to become busier over the coming years.

Virginia Cave Is The Largest Musical Instrument In The World

November 9, 2023 by 23 Comments

Hit something with a hammer, and it makes a sound. If you’re lucky, it might even make a pleasant sound, which is the idea behind the Great Stalacpipe Organ in Luray Caverns, Virginia. The organ was created in 1954 by [Leland W. Sprinkle], who noticed that some stalactites (the ones that come down from the ceiling of the cave) would make a nice, pure tone when hit.

So, he did what any self-respecting hacker would do: he picked and carved 37 to form a scale and connected them to an electronic keyboard. The resonating stalactites are spread around a 3.5 acre (14,000 square meters) cave, but because it is in a cave, the sound can be heard anywhere from within the cave system, which covers about 64 acres (260,000 square meters). That makes it the largest musical instrument in the world.

We’ll save the pedants the trouble and point out that the name is technically an error — this is not a pipe organ, which relies on air driven into resonant chambers. Instead, it is a lithophone, a percussion instrument that uses rock as the resonator. You can see one of the solenoids that hits the rock to make the sound below.

This is also the sort of environment that gives engineers nightmares: a constant drip-drip-drip of water filled with minerals that love to get left behind when the water evaporates. Fortunately, the Stalacpipe Organ seems to be in good hands: according to an NPR news story about it, the instrument is maintained by lead engineer for the caverns [Larry Moyer] and his two apprentices, [Stephanie Beahm] and [Ben Caton], who are learning the details of maintaining a complex device like this.

Continue reading “Virginia Cave Is The Largest Musical Instrument In The World” →

Apple System 7… On Solaris?

November 8, 2023 by 17 Comments

While the Unix operating systems Solaris and HP-UX are still in active development, they’re not particularly popular anymore and are mostly relegated to some enterprise and data center environments They did enjoy a peak of popularity in the 90s during the “wild west” era of windowed operating systems, though. This was a time when there were more than two mass-market operating systems commercially available, with many companies fighting for market share. This led to a number of efforts to get software written for one operating system to run on others, whether that was simply porting software directly or using some compatibility layer. Surprisingly enough it was possible in this era to run an entire instance of Mac System 7 within either of these two Unix operating systems, and this was an officially supported piece of Apple software.

The software was called the Macintosh Application Environment (MAE), and was an effort by Apple to bring Macintosh System 7 applications to various Unix-based operating systems, including Solaris and HP-UX. This was a time before Apple’s OS was Unix-compliant, and MAE provided a compatibility layer that translated Macintosh system calls and application programming interfaces (APIs) into the equivalent Unix calls, allowing Mac software to function within the Unix environments. [Lunduke] outlines a lot of the features of this in his post, including some of the details the “scaffolding” allowing the 68k processor to be emulated efficiently on the hardware of the time, the contents of the user manual, and even the memory management and layout.

What’s really jarring to anyone only familiar with Apple’s modern “walled garden” approach is that this is an Apple-supported compatibility layer for another system. At the time, though, they weren’t the technology giant they are today and had to play by a different set of rules to stay viable. Quite the opposite, in fact: they almost went out of business in the mid-90s, so having their software run on as many machines as possible would have been a perk at the time. While this era did have major issues with cross-platform compatibility, there was some software that attempted to solve these problems that are still in active development today.

Thanks to [Stephen] for the tip!

Lunar Gateway’s Advanced Solar Electric Propulsion Engine Passes Initial Qualification Tests

November 8, 2023 by 8 Comments

Recently NASA announced earlier this month that the 12 kW Advanced Electric Propulsion System (AEPS) — which is scheduled to form an integral part of the Lunar Gateway when it is launched — has passed a number of qualification tests, after a rather tumultuous number of years during its development.

Top-Level PPE Conceptual Ion Propulsion System (IPS) Block Diagram. (Credit: NASA)
Top-Level PPE Conceptual Ion Propulsion System (IPS) Block Diagram. (Credit: NASA)

Originally designed since 2015 to propel the AARM mission to fetch rocks from an asteroid, when AARM was cancelled it became the cornerstone of the Lunar Gateway that should enable astronauts in the Artemis program to land on the Moon.

The AEPS is a solar electric propulsion system that uses xenon as its propellant, much like existing ion engines. Where it differs is in the power output, which should allow it to work as the primary propulsion method for large deep space and cargo missions. Much of the development and projections are covered in a 2017 presentation at the International Electric Propulsion Conference (IEPC).

Although the projected dates for much in this presentation (e.g. first flight of SLS Block 1 was in 2022, not 2018) are decidedly off, once the individual AEPS thrusters are validated, three strings will be mounted on the Power and Propulsion Element (PPE) that forms the core of the Lunar Gateway and is scheduled to be launched in November of 2025.

Top image: AEPS installed for testing at NASA Glenn. (Credit NASA)

Getting PCIe Working On The New Pi 5

November 8, 2023 by 36 Comments

After the Pi 4 released, a discovery was quickly made that the internals of the popular single-board computer use PCIe to communicate with each other. This wasn’t an accessible PCIe bus normally available in things like desktop computers for expansion cards, though; this seemed to be done entirely internally. But a few attempts were made to break out the PCIe capabilities and connect peripherals to it anyway, with varying levels of success. The new Pi 5 seems to have taken that idea to its logical conclusion and included a PCIe connector, and [George] is showing us a way to interface with this bus.

The bus requires the port to be enabled, but once that’s done it’s ready to be used. First, though, some support circuitry needs to be worked out which is why [George] is reverse engineering the system to see what’s going on under the hood. There are a few handshakes that happen before it will work with any peripherals, but with that out of the way a PCIe card can be connected. [George] removed the connector to solder wires to the board directly in order to connect a proper PCIe port allowing a variety of cards to be connected, in this case a wireless networking card and an old Firewire card. This specific build only allows Gen 1 speeds, but the bus itself supports faster connections in theory with better wiring and support circuitry.

While it might not be the prettiest solution, as [George] admits, it does a great job of showing the inner workings of this communication protocol and its use in the new, more powerful Raspberry Pi 5. This makes a lot of things more accessible, such as high-speed PCIe HATs allowing for a wide range of expansion for these popular single-board computers, which wouldn’t have been possible before. If you’re still stuck with a Pi 4, though, don’t despair. You can still access the PCIe bus on these older models but it’ll take a little bit more work.

Thanks to [CJay] for the tip!

Continue reading “Getting PCIe Working On The New Pi 5” →

An Open-Source Ebike Motor Controller

November 8, 2023 by 18 Comments

DIY e-bikes are often easy to spot. If they’re not built out of something insane like an old washing machine motor, the more subtle kits that are generally used still stand out when compared to a non-assisted bike. The motors tend to be hub- or mid-drive systems with visible wires leading to a bulky battery, all of which stand out when you know what to look for. To get a stealthy ebike that looks basically the same as a standard bicycle is only possible with proprietary name-brand solutions that don’t lend themselves to owner repair or modification, but this one has at least been adapted for use with an open source motor controller.

The bike in use here is a model called the Curt from Estonian ebike builder Ampler, which is notable in that it looks indistinguishable from a regular bicycle with the exception of the small 36-volt, 350-watt hub motor somewhat hidden in the rear wheel. [BB8] decided based on no reason in particular to replace the proprietary motor controller with one based on VESC, an open-source electric motor controller for all kinds of motors even beyond ebikes. Installed on a tiny Arduino, it fits inside the bike’s downtube to keep the stealthy look and can get the bike comfortably up to around 35 kph. It’s also been programmed to turn on the bike’s lights if the pedals are spun backwards, and this method is also used to change the pedal assist level, meaning less buttons and other user-interface devices on the handlebars. Continue reading “An Open-Source Ebike Motor Controller” →

Forever Writing On Monofilament Fishing Line

November 8, 2023 by 50 Comments

Collectively, we have a long-term memory problem. Paper turns to mulch, dyes in optical disks degrade, iron oxides don’t last forever, and flash memories will eventually fade away. So what do you do when you want to write something down and make sure it’s around a couple of thousand years from now? Easy — just use something that even Mother Nature herself has trouble breaking down: plastic.

Specifically, fluoropolymer fishing line, which is what [Nikolay Valentinovich Repnitskiy] uses as a medium in his “Carbon Record” project. There’s not a lot of information in the repository, but the basic idea is to encode characters by nicking the fishing line along its length. The encoder is simple enough; a spool of fresh line is fed into a machine where a solenoid drives a sharpened bolt against the filament. This leaves a series of nicks that encode the ones and zeros of 255 ASCII characters. It looks like [Nikolay] went through a couple of prototypes before settling on the solenoid; an earlier version used a brushed motor to drive the encoder, but the short, rapid movements proved too much for the motor to handle. We’ve included a video below that shows the device encoding some text; sounds a little like Morse to us.

There seems to be a lot more going on with this device than the repo lets on; we’d love to know what the big heat sink on top is doing, for instance. Hopefully we’ll get more details, including how [Nikolay] intends to decode the dents. Or perhaps that’s an exercise best left to whoever finds these messages a few millennia hence.