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Hackaday Links: August 21, 2022

As side-channel attacks go, it’s one of the weirder ones we’ve heard of. But the tech news was filled with stories this week about how Janet Jackson’s “Rhythm Nation” is actually a form of cyberattack. It sounds a little hinky, but apparently this is an old vulnerability, as it was first noticed back in the days when laptops commonly had 5400-RPM hard drives. The vulnerability surfaced when the video for that particular ditty was played on a laptop, which would promptly crash. Nearby laptops of the same kind would also be affected, suggesting that whatever was crashing the machine wasn’t software related. As it turns out, some frequencies in the song were causing resonant vibrations in the drive. It’s not clear if anyone at the time asked the important questions, like exactly which part of the song was responsible or what the failure mode was on the drive. We’ll just take a guess and say that it was the drive heads popping and locking.

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A Deeper Dive Into Reverse Engineering With A CT Scanner

We’ve recently got a look at how [Ken Shirriff] used an industrial CT scanner as a reverse engineering tool. The results were spectacular, with pictures that clearly showed the internal arrangement of parts that haven’t seen the light of day since the module was potted back in the 60s. And now, [Ken]’s cohort [Curious Marc] has dropped a video with more detail on the wonderful machine, plus deep dives into more Apollo-era hardware

If you liked seeing the stills [Ken] used to reverse engineer the obscure flip-flop module, you’re going to love seeing [Marc] using the Lumafield scanner’s 3D software to non-destructively examine several Apollo artifacts. First to enter the sample chamber of the CT scanner was a sealed module called the Central Timing Equipment, which served as the master clock for the Apollo Command Module. The box’s magnesium case proved to be no barrier to the CT scanner’s beam, and the 3D model that was built up from a series of 2D images was astonishingly detailed. The best part about the virtual models is the ability to slice through them in any plane — [Marc] used this feature to hunt down the clock’s quartz crystal. Continue reading “A Deeper Dive Into Reverse Engineering With A CT Scanner”

CT Scans Help Reverse Engineer Mystery Module

The degree to which computed tomography has been a boon to medical science is hard to overstate. CT scans give doctors a look inside the body that gives far more information about the spatial relationship of structures than a plain X-ray can. And as it turns out, CT scans are pretty handy for reverse engineering mystery electronic modules, too.

The fact that the mystery module in question is from Apollo-era test hardware leaves little room for surprise that [Ken Shirriff] is the person behind this fascinating little project. You’ll recall that [Ken] recently radiographically reverse engineered a pluggable module of unknown nature, using plain X-ray images taken at different angles to determine that the undocumented Motorola module was stuffed full of discrete components that formed part of a square wave to sine wave converter.

The module for this project, a flip-flop from Motorola and in the same form factor, went into an industrial CT scanner from an outfit called Lumafield, where X-rays were taken from multiple angles. The images were reassembled into a three-dimensional view by the scanner’s software, which gave a stunningly clear view of the components embedded within the module’s epoxy body. The cordwood construction method is obvious, and it’s pretty easy to tell what each component is. The transistors are obvious, as are the capacitors and diodes. The resistors were a little more subtle, though — careful examination revealed that some are carbon composition, while others are carbon film. It’s even possible to pick out which diodes are Zeners.

The CT scan data, along with some more traditional probing for component values, let [Ken] reverse engineer the whole circuit, which turned out to be a little different than a regular J-K flip-flop. Getting a non-destructive look inside feels a little like sitting alongside the engineers who originally built these things, which is pretty cool.

Reverse Engineering An Apollo-Era Module With X-Ray

The gear that helped us walk on the Moon nearly 60 years ago is still giving up its mysteries today, with some equipment from the Apollo era taking a little bit more effort to reverse engineer than others. A case in point is this radiographic reverse engineering of some Apollo test gear, pulled off by [Ken Shirriff] with help from his usual merry band of Apollo aficionados.

The item in question is a test set used for ground testing of the Up-Data Link, which received digital commands from mission controllers. Contrary to the highly integrated construction used in Apollo flight hardware, the test set, which was saved from a scrapyard, used more ad hoc construction, including cards populated by mysterious modules. The pluggable modules bear Motorola branding, and while they bear some resemblance to ICs, they’re clearly not.

[Ken] was able to do some preliminary reverse-engineering using methods we’ve seen him employ before, but ran into a dead end with his scope and meter without documentation. So the modules went under [John McMaster]’s X-ray beam for a peek inside. They discovered that the 13-pin modules are miniature analog circuits using cordwood construction, with common discrete passives stacked vertically between parallel PCBs. The module they imaged showed clear shadows of carbon composition resistors, metal-film capacitors, and some glass-body diodes. Different angles let [Ken] figure out the circuit, which appears to be part of a square wave to sine wave converter.

The bigger mystery here is why the original designer chose this method of construction. There must still be engineers out there who worked on stuff like this, so here’s hoping they chime in on this innovative method.

Can You Hear Me Now? Lunar Edition

Despite what it looks like in the movies, it is hard to communicate with astronauts from Earth. There are delays, and space vehicles don’t usually have a lot of excess power. Plus everything is moving and Doppler shifting and Faraday rotating. Even today, it is tricky. But how did Apollo manage to send back TV, telemetry, and voice back in 1969? [Ken Shirriff] and friends tell us part of the story in a recent post where he looks at the Apollo premodulation processor.

Things like weight and volume are always at a premium in a spacecraft, as is power. When you look at pictures of this solid box that weighs over 14 pounds, you’ll be amazed at how much is crammed into a relatively tiny spot. Remember, if this box was flying in 1969 it had to be built much earlier so there’s no way to expect dense ICs and modern packaging. There’s not even a printed circuit board. The components are attached to metal pegs in a point-to-point fashion. The whole thing lived near the bottom of the Command Module’s lower equipment bay.

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The Apollo Digital Ranging System: More Than Meets The Eye

If you haven’t seen [Ken Shirriff]’s teardowns and reverse engineering expeditions, then you’re in for a treat. His explanation and demonstration of the Apollo digital ranging system is a fascinating read, even if vintage computing and engineering aren’t part of your normal fare.

The average Hackaday reader should be familiar with the concept of determining the distance of a faraway object by measuring how long it takes a sound or radio wave to be reflected, such as in sonar and radar. Going another step and measuring Doppler Shift – the difference in the returned signal’s frequency – will tell us the velocity of the object relative to our position. It’s so simple that an Arduino can do it. But in the days of Apollo, there was no Arduino. In fact, there were no Integrated Circuits. And Apollo missions went all the way to the moon- far too distant for relatively simple Radar measurements. Continue reading “The Apollo Digital Ranging System: More Than Meets The Eye”

NASA Continues Slow And Steady Pace Towards Moon

It’s often said that the wheels of government turn slowly, and perhaps nowhere is this on better display than at NASA. While it seems like every week we hear about another commercial space launch or venture, projects helmed by the national space agency are often mired by budget cuts and indecisiveness from above. It takes a lot of political will to earmark tens or even hundreds of billions of dollars on a project that could take decades to complete, and not every occupant of the White House has been willing to stake their reputation on such bold ambitions.

In 2019, when Vice President Mike Pence told a cheering crowd at the U.S. Space & Rocket Center that the White House was officially tasking NASA with returning American astronauts to the surface of the Moon by 2024, everyone knew it was an ambitious timeline. But not one without precedent. The speech was a not-so-subtle allusion to President Kennedy’s famous 1962 declaration at Rice University that America would safely land a man on the Moon before the end of the decade, a challenge NASA was able to meet with fewer than six months to spare.

Unfortunately, a rousing speech will only get you so far. Without a significant boost to the agency’s budget, progress on the new Artemis lunar program was limited. To further complicate matters, less than a year after Pence took the stage in Huntsville, there was a new President in the White House. While there was initially some concern that the Biden administration would axe the Artemis program as part of a general “house cleaning”, it was allowed to continue under newly installed NASA Administrator Bill Nelson. The original 2024 deadline, at this point all but unattainable due to delays stemming from the COVID-19 pandemic, has quietly been abandoned.

So where are we now? Is NASA in 2022 any closer to returning humanity to the Moon than they were in 2020 or even 2010? While it might not seem like it from an outsider’s perspective, a close look at some of the recent Artemis program milestones and developments show that the agency is at least moving in the right direction.

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