Things might be getting a bit dicey out in Jezero crater for Ingenuity. The little helicopter that could is starting to have trouble dealing with the thinning Martian atmosphere, and may start pressing against its margin of safety for continued operation. Ingenuity was designed for five flights that would all take place around the time its mothership Perseverance touched down on Mars back in February, at which time the mean atmospheric pressure was at a seasonal high. Over the last few months, the density of the Martian atmosphere has decreased a wee bit, but when you’re starting with a plan for a pressure that’s only 1.4% of Earth’s soupy atmosphere, every little bit counts. The solution to keeping Ingenuity flying is simple: run the rotors faster. NASA has run a test on that, spinning the rotors up to 2,800 RPM, and Ingenuity handled the extra stresses and power draw well. A 14th flight is planned to see how well the rotors bite into the rarefied air, but Ingenuity’s days as a scout for Perseverance could be numbered.

If you thought privacy concerns and government backdoors into encryption technology were 21st-century problems, think again. IEEE Spectrum has a story about “The Scandalous History of the Last Rotor Cipher Machine,” and it’s a great read — almost like a Tom Clancy novel. The story will appeal to crypto — not cryptocurrency — fans, especially those fascinated by Enigma machines, because it revolves around a Swiss rotor cipher machine called the HX-63, which was essentially a refinement of the original Enigma technology. With the equivalent of 2,000-bit encryption, it was considered unbreakable, and it was offered for sale to any and all — at least until the US National Security Agency sprung into action to persuade the inventor, Boris Hagelin, to shelve the HX-63 project in favor of electronic encryption. The NSA naturally helped Hagelin design this next generation of crypto machines, which of course all had backdoors built into them. While the cloak and dagger aspects of the story — including a possible assassination of Boris Hagelin’s son in 1970, when it became clear he wouldn’t “play ball” as his father had — are intriguing, the peek inside the HX-63, with its Swiss engineering, is the real treat.

One of the great things about the internet is how easy it is to quickly answer completely meaningless questions. For me, that usually involves looking up the lyrics of a song I just heard and…

Continue reading: https://hackaday.com/2021/09/19/hackaday-links-september-19-2021/

Source: hackaday.com