Kritik sah

If you’ve watched a Saturn V launch, you’ve probably seen how a large rocket will often jettison a stage on the way up. There are several reasons for this — there is no reason to haul an empty fuel container, for example. However, you can probably imagine how the separation works. You release something — probably explosive bolts — and gravity pulls the old stage away from you as you climb on the next stage’s engines. But what about on the way back? The command module drops the service module before reentry. [Apollo11Space] has a video explaining just how complicated that was to pull off . You can watch it below. The main problem? The service module has almost everything you need: oxygen, a big engine, fuel, and electrical generation capability. If you’ve ever seen a real command module, they are tiny. Somehow, you need to get the command module prepared to be on its own for the amount of time it takes to land, and get the service module safely ...

If you’ve been interested in FreeCAD but haven’t known where to start, here’s a wonderful video tutorial for FreeCAD 1.1 by [Deltahedra] aimed squarely at how to model a 3D part from scratch while also following best engineering practices for part design. It focuses on a concise and meaningful workflow that respects your time and doesn’t make assumptions about skill level. It even starts by taking a few moments to explain how to navigate the interface, a courtesy many will appreciate. FreeCAD can do quite a lot, so a tutorial that focuses on a specific yet broadly-applicable task with a clear context is a great way to narrow the scope into something manageable, and be comprehensive without getting bogged down in minutiae. [Deltahedra] does this by exclusively using the part design workbench, demonstrating what to do to make a part step-by-step, and showing common mistakes that can happen and how to fix them if they occur. Beyond that, it’s left up to the...

As time marches on, the retro gaming community gets more and more access to older systems. This is partially a product of modern computing having much more power to emulate more demanding systems, but also because many in the community have spent more time with their favorite systems. Such is the case for [tschicki] who has spent considerable time and effort reverse engineering the Playstation 2 to come up with this custom mainboard for a handheld version that still uses some of the original chips from the console. This Playstation 2 handheld console is designed almost completely from the ground up, not just including the impressive main board but also its modernized features, including USB power delivery handled by an RP2040, digital video output, support for modern storage media like SD cards, a customized boot ROM, and upgraded audio. The DualShock 2 controller is also implemented within the handheld, and the case itself is designed to be 3D printed. It’s an impressive effort...

Arbitrary command execution with the Wi-Fi password. (Credit: Benn Jordan) Continuing on his quest to expose the dark underbelly of modern technology, [Benn Jordan] recently did a deep-dive into the rise of so-called robot dogs. Although their most striking resemblance with biological dogs is that they also have four legs and generally follow commands, [Benn] found many issues with them that range from safety issues due to limited sensory capabilities, to basic security vulnerabilities, all the way to suspicious network traffic from Unitree’s robot dog firmware. Although not the only seller of this type of quadruped robot, Unitree Robotics has made a name for itself by offering very capable and yet very cheap products. Their basic quadruped robot costs only a few thousand clams and features Lidar and heaps of processing power, all of which should make it a pretty useful device. Despite this, [Benn] found that the original task that he’d envisioned for the robot, as in p...

In the search for more exciting broken electronics to repair, [Hugh Jeffreys] bought a GoPro Hero 10 for US$100 with an apparently rather common issue of no camera input, along with a cracked display . This particular camera issue is rather obvious, with just darkness where the camera’s input should appear on the display. Since [Hugh] already needed a spare display, he figured that he might as well get an even more broken GoPro Hero 10 for parts. Another US$40 later, [Hugh] found himself the proud owner of a second GoPro, this one being water damaged and no longer turning on. Getting to the internals requires removing the glued-in display, which is even trickier than with a smartphone. By inserting a thin blade, adding solvents and not prying, you can slowly work it loose. With two disassembled GoPros it was now possible to swap modules. After a factory reset and firmware update had failed to fix the first GoPro, the camera module from the donor unit was inserted, but this made ...

Aside from nostalgia, people claim to like CRTs because they’re apprehendable– the technology just makes more sense than the arcane wibbly-wobbly solid-state madness going on inside the driver chip of your new OLED. CRTs weren’t the first technology used to display moving images though, and their mechanical forebears were even easier to understand. For that reason we suppose it was only a matter of time before one of The Youths– in this case a British YouTuber by the name of [smill]–tried gaming on a mechanical television display. The game in question was Minecraft — because of course it was, that’s the new generation’s DOOM –and the mechanical TV in question is not a priceless 1920s antique but a commercial kit that reproduces [John Logie Baird]s 1925 televisor. If you’re not familiar, it uses a flat disk– called a Nipkow disk after its inventor– with a series of holes in a spiral to demodulate a single lamp...