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September 5, 2021 Archives

Sunday, September 5, 2021

THE HAPPENING WORLD: Mars Helicopter Ingenuity Completes 13th Flight

Ingenuity has now been operating on Mars for 141 sols (Martian days), far beyond its planned 30 day technology demonstration mission. It is now being used to scout destinations and routes for the Perseverance rover, which deployed it on 2021-04-03. Here is a pre-flight summary of the plan for flight 13.

Posted at 13:30 Permalink

TRACKING WITH CLOSEUPS: Single Event Upsets—Computer Crashes from Deep Space

Note that while error correction code (ECC) memory can dramatically reduce the vulnerability of computer systems to errors induced by cosmic rays or other exogenous sources (memory arrays are very dense and have few electrons per storage cell, and thus present both a large and soft target), the logic circuits within processors and other electronics remain at risk and, except for special-purpose and very expensive “radiation hardened” or multiple redundant hardware designed for aerospace applications, are not protected against upsets.

Single event upsets due to cosmic rays do not damage electronics: they just cause transient errors where the computer does something it isn't supposed to. This makes it extremely difficult to diagnose the source of the problem, and when something apparently inexplicable happens due to poorly designed and incompetently implemented software (for example, that intermittently operating system famed for its “blue screen of death”), its sloppy perpetrators sometimes blame it instead on “a cosmic ray”. It does happen, but usually it's crappy code.

Posted at 12:45 Permalink

CONTINUITY: Colour-Motion Optical Illusion

Posted at 12:21 Permalink

THE HAPPENING WORLD: Weekly Space Report: Starbase Infrastructure, Cargo to ISS, Smallsat Stumbles

Posted at 11:33 Permalink