NASA’s Just Prolonged Voyager 2’s Science Mission With A Big Bang

Letting go is hard, especially when it concerns an irreplaceable space probe like the two Voyagers. Fortunately JPL engineers have managed to pull off a ‘big bang’ switch on Voyager 2, involving two heaters and another device that was kept on to keep providing sufficient heat to the spacecraft to allow it to keep functioning. After all, while the vacuum of space isn’t cold, out in deep space you’re radiating away all your precious heat.

Unfortunately the official press release in exceedingly limited in details, but The Register was kind enough to already nag a NASA spokesperson about it, which gives us some technical details. The short version is that these heaters don’t just keep the electronics within a happy operating range, they also keep the fuel lines warm and capable of providing fuel for attitude adjustments.

With this switch apparently enough of the rapidly diminishing power from the RTG has been freed up that the Voyager 2 has just gained a whole extra year on its extended mission. The JPL team hopes to perform the same switch on the Voyager 1 spacecraft soon, giving it a similar boost to its expected lifespan, before both of them go quiet in the depths of space.

Thanks to [Mark Stevens] for the tip.

Rubidium Frequency Standard Explained

You’ve probably heard of rubidium frequency standards, which are used where you need an extremely accurate time or frequency reference. [IMSAI] guy has a good explainer video about what’s actually going on inside one of these standards. Much of the basic idea also applies to cesium standards.

The explainer starts with the periodic table. Rubidium and cesium are both alkali metals, with a single electron in their outermost electron shell. Rubidium has 37 electrons, with the outermost one relatively loosely bound. Naturally occurring rubidium consists mainly of two isotopes, rubidium-85 and rubidium-87, which have the same number of protons and electrons but different numbers of neutrons.

A rubidium standard typically has three gas cells that have a bit of rubidium in them. An RF-excited rubidium-87 discharge lamp produces light at very specific wavelengths. The RF energy excites rubidium atoms into higher electronic states, and when their electrons fall back to lower-energy states, the atoms emit photons.

That light passes through a filter cell containing rubidium-85. The filter preferentially absorbs part of the lamp’s spectrum, leaving light that optically pumps the rubidium-87 atoms in the second resonance cell into one of two closely spaced hyperfine states of the atom’s ground state.

Those two states differ because of the interaction between the magnetic moment of the outer electron and that of the rubidium-87 nucleus. Their energy separation corresponds to a microwave frequency of about 6.835 GHz.

The resonance cell is illuminated by the filtered light while also being exposed to microwave energy from a local oscillator. When the microwave frequency is exactly equal to the rubidium-87 hyperfine transition frequency, it transfers atoms between the two ground-state hyperfine levels. That changes how strongly the cell absorbs the optical pumping light, producing a detectable dip in the light reaching a photodetector.

Electronics then servo the microwave oscillator onto the center of that absorption dip, using a feedback technique somewhat analogous to a phase-locked loop. Once locked, the oscillator is effectively referenced to an atomic transition rather than to the dimensions or mechanical properties of a crystal, giving you an extremely stable frequency standard.

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Phantomdrive Keeps Your Secrets Out Of Sight

It’s a complex world out there, and more than ever folks may find themselves in a situation where they want to keep particular bits of information away from prying eyes. At the same time, overly complex methods of file security can make it difficult to share said information with the intended recipients impractical. So what’s the solution?

One proposal from [Ryan Walker] AKA [machinehum] is the Phantomdrive — a fully open source USB flash drive that features a secret secondary filesystem. Not only is the existence of this data hidden from the operating system under normal circumstances, but it’s encrypted with AES-256. Rather than relying on software running on the computer to handle the decryption, the CH569 chip that powers the drive does it internally.

To complete this platform-agnostic approach, [machinehum] had to come up with a way for the user to unlock the secure storage that didn’t require running any code on the client machine. A hardware solution such as a keypad is the obvious answer, but in this case, was out of the question as it would immediately tip off an observer about the drive’s true nature. A covert storage device needs a similarly inconspicuous method of authentication.

That’s why the firmware on the Phantomdrive keeps an eye on all the write operations to the unsecured section of the drive looking for the string password:. Once it sees that, it treats whatever follows as the decryption key. If it’s correct, the previously inaccessible data will appear to the operating system as a new drive.

[machinehum] cautions that none of this has been professionally audited from a security standpoint, and that you should treat this whole concept as an experiment. In other words, it’s probably more than sufficient for the average person, but no guarantees on how long it would last should a three letter agency gets too interested in what you’re up to.

If this seems a bit familiar, it’s because the Phantomdrive follows up [machinehum]’s self-destructing USB flash drive from a few years back. The concept is essentially the same, except this time there’s no Magic Smoke getting released.

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CNC’d, CNC-inspired Adjustable Wrench Won’t Round Your Bolts

We’ve probably all got one item in our toolboxes or chests that we really, really don’t like, but find too handy to toss. For [Someone Should Make That], that item was the bolt-rounding adjustable wrench. Rather than continuing to gripe about it, or alter his habits to make greater use of the full wrench set he also owns, he decided to build a better mousetrap. By mousetrap, we mean adjustable wrench.

It took a couple of iterations on-screen before he hits on a solution that seems to work quite well indeed. The problem [Someone] had with his adjustable wrench was one of physical slop: once adjusted, there’s just too much play in the mechanism, which results in rounded-off bolt heads. [Someone]’s CNC’d solution takes inspiration from the CNC machine that manufactures it: he’s using spring-loading in the adjustment screw akin to what you find in the anti-backlash nut on your CNC mill or 3D printer’s ball threads. The tension from the springs keeps the wrench tight to the bolt, and that keeps [Someone] from rounding them off. Speaking of 3D printers, he prototyped in plastic before machining, and the screw in the end product stayed that way. It would be interesting to see how well that holds up.

Not only do we appreciate that it’s solved a common problem many of us have, the ethos of “this angers me, so I shall hack it” is one we support 100%, so do give a watch unless you’re one of those people who absolutely can’t stand videos, even when they’re spring-loaded to have no slop. There’s some good tips for beginner CNC operators in there, too.

This isn’t the first time someone’s tried to reinvent this particular wheel, though the last version we liked was a ratchet.

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Calculus-Free PID (Almost) In A Spreadsheet

PID controllers are everywhere. They regulate temperature, motor speed, power supplies, positioning systems, process equipment, and probably a dozen things within arm’s reach of you right now.

They’re also frequently explained with enough calculus to make them seem more mysterious than they really are. Granted, the I and D in PID stand for calculus terms, but they are easy enough to build into a spreadsheet. Grab a copy and keep it open while you read this post.

The Google Sheet implements a simple simulated PID controller along with a simulated process — the thing we’re trying to control. You can change the controller gains, alter the process, introduce disturbances, and watch what happens without compiling anything or wiring up a heater that might accidentally become a toaster. Continue reading “Calculus-Free PID (Almost) In A Spreadsheet”

Going Full Fruity With Apple’s 1999 High-End Power Mac G3

Back in the late 90s, Apple was definitely a pretty fruity company, with its aggressively translucent shades of colored plastic that often got described in terms of such fruit variants. Although the iMac steals a lot of the glory here, the Power Mac series and associated hardware deserves that spot in the limelight as well. Recently [Dan Wood] put together a full Power Mac G3-based setup, including the appropriate LCD monitor and other peripherals as someone with some serious disposable income back in 1999 might have owned.

Why Macs are better than PCs. (Credit: Dan Wood, YouTube)
Why Macs are better than PCs. (Credit: Dan Wood, YouTube)

Part of Steve Jobs’ return to Apple, the Power Macintosh G3 debuted first in basically recycled beige enclosures from previous Macintosh systems before its second generation introduced the Blue and White version, as it was officially called. This dazzling style was carried through in the peripherals, with pin stripes, translucent plastic and a distinct absence of sharp corners or edges.

As for what you get in these colorful Power Mac G3s, a 300 to 450 MHz CPU, an official memory limit of 192 MB and perhaps the most user-friendly way to access the logic board to upgrade and install components with the folding lid. Something which had PC users with sharp edged cases and plentiful blood sacrifices to the PC gods somewhat steaming in jealousy.

For the time these Power Mac G3s didn’t just look fetching, they also were quite powerful. Something which came at a pretty hefty price tag, of course. The 400 MHz model that [Dan] got his paws on would have cost around $2,000 back in 1999, or closer to $4,000 clams today. The active-matrix TFT LCD screen would have been cutting edge as well, with a similar cutting edge price tag.

Released before OS X this system runs Mac OS 8.6, though it can run OS X 10.4 (Tiger) which unlocks more software options and of course the transition to a proper multi-tasking OS. This particular system was apparently used for graphics design until 2010 based on the files on the HDD. As demonstrated in the video, the system is still quite usable, even in 2026, thanks to all the software available online.

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FitzRoy’s Glass: Victorian Weather Marvel Or Glorified Thermometer?

Everyone talks about the weather. This is doubly true for sailors, where bad weather could mean a very bad day. So it isn’t surprising that navies around the world have had a keen interest in weather forecasting. But how did you predict the weather before modern instruments, radar, and satellite images? Vice Admiral Robert FitzRoy had great faith in “storm glasses,” a glass chamber containing some chemicals that he didn’t invent, but did document and promote heavily during the 1860s.

Did it work? Apparently not, but the device is still interesting in its own right. FitzRoy was a pioneer of meteorology, replacing folklore with actual observations and attempts at scientific rigor. While he did arm observation stations with conventional things like thermometers and barometers, he was also a proponent of the weather glass. Continue reading “FitzRoy’s Glass: Victorian Weather Marvel Or Glorified Thermometer?”