• Cheating your way into space

    04/04/2018 at 18:58 0 comments

    With US still over 1 year away from being able to launch humans into space again, what a story it would be if someone stowed away in a cargo mission. It would be like a Doolittle raid, but a raid against bureaucracy & management. It would be riskier than Alan Shepard's 1st flight, because the cargo modules have no launch abort capability. Beyond that, it would be the same as that 1st flight, despite all the concern about minutiae in the flight termination system, life support system, & micro meteoroids. Indeed, much of the last 8 years of pain has been micro meteoroid shielding standards.

    The stowaway would be a man, of course. He would have a food supply & a bathroom hidden somewhere. Once on the space station, they would have the issue of feeding him, not having enough room in the Soyuzes to evacuate the station, the life support system encountering loads not seen in 8 years.

    The real drama would be the consequences of stowing away. Would he be shot for treason? Would NASA give up on human spaceflight entirely because they couldn't enforce enough meaningless regulations? Would private space programs tolerate more risk?

  • retro computing & lions

    04/02/2018 at 00:21 0 comments

    Ready Player One might be the peak of retro computing fever or at least the peak of attention to it.  FVWM was written in 1993. XTerm was written in 1984. NEdit was written in 1992. X11 began in 1984. So lions have manely used the same tools since 1995 & those tools date back to the Commodore 64.

    Lions were into retro computing long before retro computing was a fad, but manely in a UNIX sense rather than an 8 bit PC sense. There was always a fascination with the simplicity of these tools compared to the massive marketing gimmicks that modern interfaces have become. X11 is still the only thing which actually works over a network.

    After the decline of early 8 bit PCs, early UNIX workstations were the only computers that interested lions. They were more expensive & capable than what any private individual could afford, yet since the introduction of Linux, could be recreated on any PC hardware.

    The retro computing fad has sorely overlooked early UNIX workstations from the same time period. Millenials know what Koala paint was, but not what XTerm was. It's based on what consumers could afford. Lions have been lucky to be able to base most of their income on using retro tools, though it may not be the most productive way to go.

  • Stopping an op-amp from oscillating

    03/30/2018 at 22:25 0 comments

    How quickly 1 project to make an op-amp oscillate turned to another project to stop an op-amp from oscillating. The internet says op-amp oscillations are caused by very high frequency op-amps with slight delays between the output & feedback. Capacitance on the output & feedback terminals & higher feedback resistors cause delays just like an RC circuit. They recommend lower feedback resistors & a resistive load for the output.

    100 & 200 were the lowest reasonable feedback resistors, but this caused the ADA4817 to oscillate at 80Mhz. Increasing to 1k & 2k actually seemed to eliminate the oscillation. The output of each op-amp is very noisy, but when combined in a difference amplifier, it's relatively clean.  The only explanation is if physics experiments never work, pick what doesn't work to make them work.  Perhaps having the output impedance too low slowed down its response rate & caused it to oscillate.