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Voyager 1 Completes Tricky Thruster Reconfiguration

September 11, 2024 by 17 Comments

After 47 years it’s little wonder that the hydrazine-powered thrusters of the Voyager 1, used to orient the spacecraft in such a way that its 3.7 meter (12 foot) diameter antenna always points back towards Earth, are getting somewhat clogged up. As a result, the team has now switched back to the thrusters which they originally retired back in 2018. The Voyager spacecraft each have three sets (branches) of thrusters. Two sets were originally intended for attitude propulsion, and one for trajectory correction maneuvers, but since leaving the Solar System many years ago, Voyager 1’s navigational needs have become more basic, allowing all three sets to be used effectively interchangeably.

The first set was used until 2002, when clogging of the fuel tubes was detected with silicon dioxide from an aging rubber diaphragm in the fuel tank. The second set of attitude propulsion thrusters was subsequently used until 2018, until clogging caused the team to switch to the third and final set. It is this last set that is now more clogged then the second set, with the fuel tube opening reduced from about 0.25 mm to 0.035 mm. Unlike a few decades ago, the spacecraft is much colder due energy-conserving methods, complicating the switching of thruster sets. Switching on a cold thruster set could damage it, so it had to be warmed up first with its thruster heaters.

The conundrum was where to temporarily borrow power from, as turning off one of the science instruments might be enough to not have it come back online. Ultimately a main heater was turned off for an hour, allowing the thruster swap to take place and allowing Voyager 1 to breathe a bit more freely for now.

Compared to the recent scare involving Voyager 1 where we thought that its computer systems might have died, this matter probably feels more routine to the team in charge, but with a spacecraft that’s the furthest removed man-made spacecraft in outer space, nothing is ever truly routine.

Reinforcing Plastic Polymers With Cellulose And Other Natural Fibers

September 9, 2024 by 9 Comments

While plastics are very useful on their own, they can be much stronger when reinforced and mixed with a range of fibers. Not surprisingly, this includes the thermoplastic polymers which are commonly used with FDM 3D printing, such as polylactic acid (PLA) and polyamide (PA, also known as nylon). Although the most well-known fibers used for this purpose are probably glass fiber (GF) and carbon fiber (CF), these come with a range of issues, including their high abrasiveness when printing and potential carcinogenic properties in the case of carbon fiber.

So what other reinforcing fiber options are there? As it turns out, cellulose is one of these, along with basalt. The former has received a lot of attention currently, as the addition of cellulose and similar elements to thermopolymers such as PLA can create so-called biocomposites that create plastics without the brittleness of PLA, while also being made fully out of plant-based materials.

Regardless of the chosen composite, the goal is to enhance the properties of the base polymer matrix with the reinforcement material. Is cellulose the best material here?

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Orion Ceases Operations, Future Of Meade Unclear

September 9, 2024 by 24 Comments

There was a time when building a telescope was a rite of passage for budding astronomers, much as building a radio was the coming age for electronics folks. These days, many things are cheaper to buy than build, even though we do enjoy building anything we can. Orion was a big name in telescopes for many years. Their parent company also owned Meade and Coronado, both well-known optical brands. A recent video from [Reflactor] brought it to our attention that Orion abruptly ceased operations on July 9th.

We always hate to hear when well-known brands that serve a big part of our community vanish. According to [Reflactor], people who have telescopes with the company for repair are likely to never see them again. [Dylan O’Donnell] also had a video about it (see below), and, as he notes, at that time, the website was still operating, but it’s gone now. To add further fuel to the fire Sky & Telescope ran an article on July 12th saying that Meade was also on the chopping block, although at the time of this writing, their site is still online.

You have to wonder what problems you might have selling telescopes today. Many people live where there is light pollution. We’d like to think there are still people who want to ponder the universe from their backyard, though.

There are still people selling telescopes, so presumably, one of them — maybe Celestron — will take up the slack. Or maybe we’ll see a resurgence in telescope homebrewing.

After all, if you have a 3D printer, you could make a 114/900 mm telescope on a tight budget. Or, try IKEA.

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Bluetooth Version 6.0 Core Specification Released

September 6, 2024 by 15 Comments

The Bluetooth SIG recently released the core specification for version 6.0 of Bluetooth. Compared to 5.x, it contains a number of changes and some new features, the most interesting probably being Channel Sounding. This builds upon existing features found in Bluetooth 5.x to determine the angle to, and direction of another device using Angle of Arrival (AoA) and Angle of Departure (AoD), but uses a new approach to much more precisely determine these parameters. as defined in the Technical Overview document for this feature.

In addition to this feature, there are also new ways to filter advertising packets, to reduce the number of packets to sift through (Decision-Based Advertising Filtering) and to filter out duplicate packets (Monitoring Advertisers). On a fundamental level, the Isochronous Adaptation Layer (ISOAL) received a new framing mode to reduce latency and increase reliability, alongside frame spacing now being negotiable and additional ways to exchange link layer information between devices.

As with any Bluetooth update, it will take a while before chipsets supporting it become widely available, and for the new features to be supported, but it gives a glimpse of what we can likely expect from Bluetooth-enabled devices in the future.

This Week In Security: EUCLEAK, Revival Hijack, And More

September 6, 2024 by 5 Comments

[Thomas Roche] of NinjaLab is out with EUCLEAK, (pdf) a physical attack against Infineon security microcontrollers, and the security tokens that contain them. The name is a portmanteau of Euclidean and leak. And no surprise, it’s a data leak in some implementations of the Extended Euclidean Algorithm (EEA), a component of an Elliptical Curve Digital Signature Algorithm (ECDSA).

OK, time to step back. Infineon microcontrollers are the digital smart parts inside popular security tokens like the Yubikey 5, some Java smart cards, and even the Infineon TPMs. These devices all serve a similar purpose. They store one or more secret keys, and are guaranteed to never disclose those keys. Instead, they use their secret keys to do cryptographic functions, like ECDSA signatures, and output the result. There’s even a special set of tests, the Common Criteria, that are intended to backstop these guarantees. What’s interesting is that an otherwise excellent product like the Yubikey 5, that passes all these auditing and certification processes, is still vulnerable.

The actual attack is to perform ECDSA signatures while monitoring the physical chip with an electromagnetic probe. This tiny directional antenna can pick up on EM noise generated by the microprocessor. That EM noise leaks timing information about the internal state of the cryptography, and the secret key can be derived as a result.

This process does require physical access to the token for several minutes. To get useful readings, the plastic case around the security token does need to be disassembled to get the probe close enough to pick up signals. From there it’s at least an hour of post-processing to actually get the key. And most of these security tokens intentionally make the disassembly process rather difficult. The point isn’t that it’s impossible to open up, but that it’s impossible not to notice that your token has been tampered with. Continue reading “This Week In Security: EUCLEAK, Revival Hijack, And More” →

If Wood Isn’t The Biomass Answer, What Is?

September 5, 2024 by 120 Comments

As we slowly wean ourselves away from our centuries-long love affair with fossil fuels in an attempt to reduce CO2 emissions and combat global warming, there has been a rapid expansion across a broad range of clean energy technologies. Whether it’s a set of solar panels on your roof, a wind farm stretching across the horizon, or even a nuclear plant, it’s clear that we’ll be seeing more green power installations springing up.

One of the green power options is biomass, the burning of waste plant matter as a fuel to generate power. It releases CO2 into the atmosphere, but its carbon neutral green credentials come from that CO2 being re-absorbed by new plants being grown. It’s an attractive idea in infrastructure terms, because existing coal-fired plants can be converted to the new fuel. Where this is being written in the UK we have a particularly large plant doing this, when I toured Drax power station as a spotty young engineering student in the early 1990s it was our largest coal plant; now it runs on imported wood pellets.

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This Week In Security: The Rest Of The IPv6 Story, CVE Hunting, And Hacking The TSA

August 30, 2024 by 1 Comment

We finally have some answers about the Windows IPv6 vulnerability — and a Proof of Concept! The patch was a single change in the Windows TCP/IP driver’s Ipv6pProcessOptions(), now calling IppSendError() instead of IppSendErrorList(). That’s not very helpful on its own, which is why [Marcus Hutchins]’s analysis is so helpful here. And it’s not an easy task, since decompiling source code like this doesn’t give us variable names.

The first question that needs answered is what is the list in question? This code is handling the option field in incoming IPv6 packets. The object being manipulated is a linked list of packet structs. And that linked list is almost always a single member list. When calling IppSendErrorList() on a list with a single member, it’s functionally equivalent to the IppSendError() in the fixed code. The flaw must be in the handling of this list with multiple members. The only way to achieve that criteria is to send a lot of traffic at the machine in question, so it can’t quite keep up with processing packets one at a time. To handle the high throughput, Windows will assemble incoming packets into a linked list and process them in batch.

So what’s next? IppSendErrorList(), takes a boolean and passes it on to each call of IppSendError(). We don’t know what Microsoft’s variable name is, but [Marcus] is calling it always_send_icmp, because setting it to true means that each packet processed will generate an ICMP packet. The important detail is that IppSendError() can have side effects. There is a codepath where the packet gets reverted, and the processing pointer is set back to the beginning of the packet. That’s fine for the first packet in the list, but because the function processes errors on the entire list of packets, the state of the rest of those packets is now much different from what is expected.

This unexpected but of weirdness can be further abused through IPv6 packet fragmentation. With a bit of careful setup, the reversion can cause a length counter to underflow, resulting in data structure corruption, and finally jumping code execution into the packet data. That’s the Remote Code Execution (RCE). And the good news, beyond the IPv6-only nature of the flaw, is that so far it’s been difficult to actually pull the attack off, as it relies on this somewhat non-deterministic “packet coalescing” technique to trigger the flaw.

Continue reading “This Week In Security: The Rest Of The IPv6 Story, CVE Hunting, And Hacking The TSA” →