kabdib 7 hours ago

Henry S F Cooper wrote a wonderful account of debugging OS race condition on the Magellan (Venus) orbiter in The Evening Star

antonvs 15 hours ago

It was technically "interstellar", but given its actual position - still inside the Oort Cloud, for example - it's a bit misleading.

It'd still take another 70+ thousand years for it to reach another star, if it was even heading in the optimal direction for that. That makes it less than 0.07% of the way to the nearest star. At interstellar scales, it's basically still on Earth's surface.

  • mkl 7 hours ago

    I think this was extrasolar, not interstellar.

  • quotemstr 14 hours ago

    Still impressive to do with those latencies. Plus, the Voyager team got very lucky --- if a different memory bank had failed, recovery might not have been possible.

    • antonvs 12 hours ago

      I agree it was impressive.

      My objection to using the word "interstellar" here is that it gives the impression that Voyager is much further away from Earth and the solar system than it really is.

      • Insanity 12 hours ago

        Eh, I agree with you but humans can’t really visualize / comprehend these distances regardless. It’s just “very far away”

        • 8note 12 hours ago

          id have gone with "extrastellar"

          its not so far to be between two stars, but its far enough from our star, at least past the firewall

          • locusofself 11 hours ago

            perhaps "extrasolar" if we want to be extra pedantic

          • tonyhart7 11 hours ago

            "at least past the firewall"

            what do you mean by this???? also where I can study these stuff

            • snitch182 10 hours ago

              Its past the influence of our sun. At least as measured by the on board tec of the time. Sort of out in the void between the stars but at these distances just barely out.

quotemstr 15 hours ago

The earlier Galileo hack was also impressive. The high gain antenna (necessary for its high speed data link) got stuck trying to unfurl and so the whole mission had to rely on the low-gain, low-speed backup antenna --- which topped out at a glorious speed of ~10 bits per second.

"The Galileo mission operations concept is undergoing substantial redesign, necessitated by the deployment failure of the High Gain Antenna, while the spacecraft is on its way to Jupiter. The new design applies state-of-the-art technology and processes to increase the telemetry rate available through the Low Gain Antenna and to increase the information density of the telemetry. This paper describes the mission planning process being developed as part of this redesign. Principal topics include a brief description of the new mission concept and anticipated science return (these have been covered more extensively in earlier papers), identification of key drivers on the mission planning process, a description of the process and its implementation schedule, a discussion of the application of automated mission planning tool to the process, and a status report on mission planning work to date. Galileo enhancements include extensive reprogramming of on-board computers and substantial hard ware and software upgrades for the Deep Space Network (DSN). The principal mode of operation will be onboard recording of science data followed by extended playback periods. A variety of techniques will be used to compress and edit the data both before recording and during playback. A highly-compressed real-time science data stream will also be important. The telemetry rate will be increased using advanced coding techniques and advanced receivers. Galileo mission planning for orbital operations now involves partitioning of several scarce resources. Particularly difficult are division of the telemetry among the many users (eleven instruments, radio science, engineering monitoring, and navigation) and allocation of space on the tape recorder at each of the ten satellite encounters. The planning process is complicated by uncertainty in forecast performance of the DSN modifications and the non-deterministic nature of the new data compression schemes. Key mission planning steps include quantifying resource or capabilities to be allocated, prioritizing science observations and estimating resource needs for each, working inter-and intra-orbit trades of these resources among the Project elements, and planning real-time science activity. The first major mission planning activity, a high level, orbit-by-orbit allocation of resources among science objectives, has already been completed; and results are illustrated in the paper. To make efficient use of limited resources, Galileo mission planning will rely on automated mission planning tools capable of dealing with interactions among time-varying downlink capability, real-time science and engineering data transmission, and playback of recorded data. A new generic mission planning tool is being adapted for this purpose."

https://ui.adsabs.harvard.edu/abs/1994smog.symp..279G/abstra...

daemonologist 5 months ago

An excellent video from Scott Manley about last year's fix of the Voyager 1 computer. Not related to the recent thruster fix.

Original title "The First Interstellar Software Update - The Insane Hack That Saved Voyager 1"; this combined with the [video] tag was too long, so I removed the "number + adjective" in accordance with the HN guidelines.