Artemis II Agenda Keeps Moon-Bound Crew Busy

With the launch of Artemis II from Cape Canaveral potentially just weeks away, NASA has been releasing a steady stream of information about the mission through their official site and social media channels to get the public excited about the agency’s long-awaited return to the Moon. While the slickly produced videos and artist renderings might get the most attention, even the most mundane details about a flight that will put humans on the far side of our nearest celestial neighbor for the first time since 1972 can be fascinating.

The Artemis II Moon Mission Daily Agenda is a perfect example. Released earlier this week via the NASA blog, the document seems to have been all but ignored by the mainstream media. But the day-by-day breakdown of the Artemis II mission contains several interesting entries about what the four crew members will be working on during the ten day flight.

Of course, the exact details of the agenda are subject to change once the mission is underway. Some tasks could run longer than anticipated, experiments may not go as planned, and there’s no way to predict technical issues that may arise.

Conversely, the crew could end up breezing through some of the planned activities, freeing up time in the schedule. There’s simply no way of telling until it’s actually happening.

With the understanding that it’s all somewhat tentative, a look through the plan as it stands right now can give us an idea of the sort of highlights we can expect as we follow this historic mission down here on Earth.

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The Rise And Fall Of Free Dial Up Internet

In the early days of the Internet, having a high-speed IP connection in your home or even a small business was, if not impossible, certainly a rarity. Connecting to a computer in those days required you to use your phone. Early modems used acoustic couplers, but by the time most people started trying to connect, modems that plugged into your phone jack were the norm.

The problem was: whose computer did you call? There were commercial dial-up services like DIALOG that offered very expensive services, such as database searches via modem. That could be expensive. You had a fee for the phone. Then you might have a per-minute charge for the phone call, especially if the computer was in another city. Then you had to pay the service provider, which could be very expensive.

Even before the consumer Internet, this wasn’t workable. Tymnet and Telenet were two services that had the answer. They maintained banks of modems practically everywhere. You dialed a local number, which was probably a “free” call included in your monthly bill, and then used a simple command to connect to a remote computer of your choice. There were other competitors, including CompuServe, which would become a major force in the fledgling consumer market.

While some local internet service providers (ISPs) had their own modem banks, when you saw the rise of national ISPs, they were riding on one of several nationwide modem systems and paying by the minute for the privilege. Eventually, some ISPs reached the scale that made dedicated modem banks worthwhile. This made it easier to offer flat-rate pricing, and the presumed likelihood of everyone dialing in at once made it possible to oversubscribe any given number of modems.

The Cost

Once consumer services like CompuServe, The Source, and AOL started operations, the cost was less, but still not inexpensive. Some early services charged higher rates during business hours, for example. There was also the cost of a phone line, and if you didn’t want to tie up your home phone, you needed a second line dedicated to the modem. It all added up.

By the late 1990s, a dial-up provider might cost you $25 a month or less, not counting your phone line. That’s about $60 in today’s money, just for reference. But the Internet was also booming as a place to sell advertising.

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Preparing To Fire Up A 90-Year-Old Boiler After Half A Century

Continuing the restoration of the #1 Lancashire boiler at the Claymills Pumping Station in the UK, the volunteers are putting on the final touches after previously passing the boiler inspection. Although it may seem that things are basically ready to start laying down a fire after the boiler is proven to hold 120 PSI with all safeties fully operating, they first had to reassemble the surrounding brickwork, free up a seized damper shaft and give a lot of TLC to mechanisms that were brand new in the 1930s and last operated in 1971.

Removing the ashes from a Lancashire boiler. (Credit: Claymills pumping station, YouTube)
Removing the ashes from a Lancashire boiler. (Credit: Claymills pumping station, YouTube)

The damper shaft is part of the damper mechanism which controls doors that affect the burn rate, acting as a kind of throttle for the boilers. Unfortunately the shaft’s bearings had seized up completely, and no amount of heat and kinetic maintenance could loosen it up again. This forced them to pull it out and manufacture a replacement, but did provide a good look at how it’s put together. The original dial indicator was salvaged, along with some other bits that were still good.

Next was to fit the cast-iron ash boxes that sit below the boiler and from where ash can be scraped out and deposited into wheelbarrows. The automatic sprinkler stokers are fitted above these, with a good look at their mechanism. The operator is given a lot of control over how much coal is being fed into the boiler, as part of the early 20th-century automation.

The missing furnace doors on the #1 boiler were replaced with replicas based on the ones from the other boilers, and some piping around the boiler was refurbished. Even after all that work, it’ll still take a few weeks and a lot more work to fully reassemble the boiler, showing just how complex these systems are. With some luck it’ll fire right back up after fifty years of slumbering and decades of suffering the elements.

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Hacking The System In A Moral Panic: We Need To Talk

It seems that for as long as there have been readily available 3D printers, there have been moral panics about their being used to print firearms. The latest surrounds a Washington State Legislature bill, HB2320, which criminalises the printing of unregistered guns. Perhaps most controversially, it seeks so impose a requirement on printers sold in the state to phone home and check a database of known firearms and refuse to print them when asked.

This has drawn a wave of protest from the 3D printing community, and seems from where we are sitting to be a spectacularly ill-conceived piece of legislation. It’s simply not clear how it could be implemented, given the way 3D printers and slicing software actually work.

Oddly This Isn’t About Firearms

The root of the problem with this bill and others like it lies in ignorance, and a misplaced belief in the power of legislation. Firearms are just the example here, but we can think of others and we’re sure you can too. Legislators aren’t stupid, but by and large they don’t come from technology or engineering backgrounds.

Meanwhile they have voters to keep happy, and therefore when a moral panic like this one arises their priority is to be seen to be doing something about it. They dream up a technically infeasible solution, push to get it written into law, and their job is done. Let the engineers figure out how to make it work. Continue reading “Hacking The System In A Moral Panic: We Need To Talk”

Fictional Moon: Reality TV And SciFi Don’t Mix

It is a safe bet that nearly all Hackaday readers like to at least imagine what it would be like to build and live in an orbital station, on the moon, or on another planet. Moon bases and colonies show up all the time in fictional writing and movies, too. For the Hackaday crowd, some of these are plausible, and others are — well — a bit fanciful. However, there’s one fictional moonbase that we think might have been too realistic: Moonbase 3.

View of the base from above.

If that didn’t ring a bell, we aren’t surprised. The six-episode series was a co-production between Twentieth Century Fox and the BBC that aired in 1973. To make matters worse, after the initial airings in the UK, Australia, and New Zealand, the video master tapes were wiped out. Until 1993, there were no known copies of the show, but then one turned up in a US television station.

The show had many links to Dr. Who and, in fact, if you think the spacesuits look familiar, they made later appearances in two Dr. Who episodes.

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How I 3D Printed My Own Lego-Compatible Train Bridges

Lego train sets have been available for decades, now. The Danish manufacturer long ago realized the magic of combining its building block sets with motors and plastic rails to create real working railways for children and adults to enjoy. Over the years, Lego has innovated through several generations of trains, from classic metal-rail systems to the more modern IR and later Bluetooth-controlled versions. The only thing largely missing over all that time, though…? A bridge!

Yes, Lego has largely neglected to build any bridges for its mainstream train lineup. There are aftermarket solutions, and innovative hacks invented by the community, all with their own limitations and drawbacks. This glaring oversight, though, seemed like a perfect opportunity to me. It was time to fire up the 3D printer and churn out a fully-realized Lego rail bridge of my very own.

Bridges Are Hard

I’ve experimented with building Lego rail bridges before, using standard track and household objects like cardboard, books, and beer. Unfortunately, it can be very difficult to support the track evenly at the joints which occur every 150mm, and derailments are common. Credit: author

There’s actually a good reason Lego bridges aren’t a big thing in the company’s own product lineup, beyond a few obscure historical parts. This is probably because they aren’t very practical. Lego locomotives are not particularly strong haulers, nor do they have excellent grip on the rails, and this makes them very poor at climbing even mild grades. Any official Lego bridge would have to be very long with a shallow slope just to allow a train to climb high enough to clear a locomotive on a track below. This would end up being an expensive set that would probably prove unpopular with the casual Lego train builder, even if the diehard enthusiasts loved it. 

There are third-party options available out there. However, most rely on standard Lego track pieces and merely combine them with supports that hold them up at height. This can work in some cases, but it can be very difficult to do cool things like passing a Lego train under a bridge, for example. It can be hard to gain enough height, and the short length of Lego track pieces makes it hard to squeeze a locomotive between supports. Continue reading “How I 3D Printed My Own Lego-Compatible Train Bridges”

The Shockley 4-Layer Diode In 2026

The physicist William Shockley is perhaps today best known for three things: his role in the invention of the transistor, his calamitous management of Shockley Semiconductor which led to a mass defection of employees and precipitated the birth of the Silicon Valley we know, and his later descent into promoting eugenics. This was not the sum of his work though, and [David Prutchi] has been experimenting with a now-mostly-forgotten device that bears the Shockley name (PDF), after finding one used in an early heart pacemaker circuit.  His findings are both comprehensive and fascinating.

The Shockley diode, or 4-layer diode as it later became known, is as its name suggests a two terminal device with a 4-layer NPNP structure. It can be modeled as a pair of complementary transistors in parallel with a reverse biased diode, and the avalanche breakdown characteristics of that diode when a particular voltage is applied to it provide the impetus to turn on the two transistors. This makes it a voltage controlled switch, that activates when the voltage across it reaches that value.

The PDF linked above goes into the Shockley diode applications, and in them we find a range of relaxation oscillators, switches, and logic circuits. The oscillators in particular could be made with the barest minimum of components, important in a time when each semiconductor device could be very expensive. It may have faded into obscurity as it was superseded by more versatile 4-layer devices such as the PUJT or silicon-controlled switch and then integrated circuits, but he makes the point that its thyristor cousin is still very much with us.

This appears to be the first time we’ve featured a 4-layer diode, but we’ve certainly covered the genesis of the transistor in the past.