After the Orion capsule of the Artemis I lunar mission returned to Earth, it was found that massive chunks of its heatshield had been ripped off, posing a serious risk to any future missions. In a recent video in which [polymatt] takes a break from repairing old laptop shells and the like, he tries to recreate the Orion’s heatshield using a variety of methods and materials.
For this test a number of samples were created, each using the same kind of segmented structure as the larger Orion heatshield. The filler was created from the published materials for the heat shield by NASA, requiring just serious mixing.
The resulting samples were then cured with thermocouples inserted, before they got blasted with the heat from a propane torch, trying to simulate the various re-entry patterns.
Perhaps unsurprisingly, the results matched the findings by NASA for why the Orion’s heat shield had failed, being the build-up of gases due to the sustained pyrolysis processes that eventually fractured the material. Despite some experimental flaws that injected residual heat from the copper structure, this still seems to be a pretty good setup to test ablative heat shields in DIY lab conditions.
When you see a listing for an Ethernet switch whose specification list is in effect ‘yes’, with a four-digit price tag when new, and with the seller asking for less than 10% of said $3,000 asking price in an ‘untested’ condition, the only rational thing to do is of course to mash that ‘buy’ button. This is what [This Does Not Compute] 
For a little while vacuum tubes and semiconductors were fighting a heated battle for dominance, with bipolar junction transistors and 1959’s RCA Nuvistor both allowing you to build a compact circuit with relatively low power usage and no high voltages. Although we now know that semiconductor technology won out overwhelmingly, that doesn’t mean that you cannot build a brand new Nuvistor board in 2026, 
As FDM printers keep getting faster, we are forced to deal with a range of bottlenecks, all of which conspire to hold us back from another Benchie world record. A major physical limitation is that of flowrate, as the hotend has to be able to melt the filament that enters the nozzle before it departs said nozzle. One attempt to make a high-flow nozzle involves splitting the material path into three winding sections, which theoretically should help said flowrate. Recently [Thomas Sanladerer] took a poke 
