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Programming Error Doomed Russian Mars Probe
astroengine writes "So it turns out U.S. radars weren't to blame for the unfortunate demise of Russia's Phobos-Grunt Mars sample return mission — it was a computer programming error that doomed the probe, a government board investigating the accident has determined."
According to the Planetary Society Blog's unofficial translation and paraphrasing of the incident report, "The spacecraft computer failed when two of the chips in the electronics suffered radiation damage. (The Russians say that radiation damage is the most likely cause, but the spacecraft was still in low Earth orbit beneath the radiation belts.) Whatever triggered the chip failure, the ultimate cause was the use of non-space-qualified electronic components. When the chips failed, the on-board computer program crashed."
Obviously the error handling routine was poorly written.
I'll assume your tongue was firmly planted in your cheek, and suggest a +1 Funny mod.
But on the chance you were serious, depending on where that chip was, it may have been beyond something manageable by software.
A chip in a power controller could take down any or all of the processor components, or render access to control circuits impossible.
The linked article also states
Everything was working well with the spacecraft immediately after launch, including deployment of the solar panels, until the command to start the engines was issued. When that did not happen, the spacecraft went into a safe mode, keeping the solar panels pointed to the Sun to maintain power.
How many times do you supposed they actually tested engine start IN THE SPACE CRAFT? I'm guessing ZERO.
non-space qualified parts being used in some of the electronics circuits. This is a design failure by the spacecraft engineers that might have been caught had they performed adequate component and system testing prior to flight. But they did not.
So design failure, due to radiation, prior to the craft getting near the strongest radiation belts. Unbelievable. Occam would be skeptical.
This sounds to me like some on-board internal source of radiation, or induction, or simple overload, fried a chip somewhere in some un-specified circuitry, most probably in the engine controls. This seems far more likely than an external radiation source given the shielding the physical design would provide.
I doubt space qualification made any difference at all. The window for space radiation in the brief time it was operational was small.
Rather I suspect under-spec parts, over voltage or high current draw, or internal shielding oversights.
Sig Battery depleted. Reverting to safe mode.
Space Micro doesn't list the prices of their components or systems, nor can I find any from anyone else. Honeywell don't list their prices either. Atmel seem to have dropped out of the field. Linear don't list the prices for their space-hardened stuff. Don't see any for BAE either, or Intersil. Empire Magnetics require a lot of personal data before they give you access to even the price classification information. Not the prices, just how they're classified.
You've got to allow for a year's worth of traveling outside of an atmosphere and then operating on Mars for the duration of the mission. This analysis of radiation for manned missions suggests you're looking at 3.5 mSv per day, then 20 rems per year in most of the places of interest.
Converting everything to rads, it's 0.1 rads per mSv and 1 rad per rem, so that's 12.75 rads to get to Mars if you assume a year-long trip, plus 20 rads for the mission, so anything with a rating of less than 32.75 rads is pretty much guaranteed to fail. However, over the course of a two years, the odds of there being a solar flare are not insignificant. To be safe, you want resistance to a further 400 rad. 432.75 rad is within the tolerance of most of the space-hardened components (some components can be taken up to 1000 rad, others up to 10,000). However, the cheapest space components would NOT survive. You're talking high-end on the space scale.
I'm going to figure that the top-line components will cost 100x that of their conventional counterparts, due to the higher-level of precision and QA that are required. It might well be a good deal more. In Russia, you've also got to pay for smuggling decent-grade hardware out of the US, as all of this stuff will be under massive amounts of regulation.
My guess is that the cuts would have saved enough that those doing the cost-cutting could buy second homes in Switzerland.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Which makes me think of something I've been wondering for awhile, now that Intel has quit making the 386 are we gonna be seeing more failures like this in the future? Because from what i understand Intel kept making the 386 rev for so damned long (last chip rolled out in 09 IIRC) because its large die area and primitive but functional design made it trivial to harden for military and aerospace use. Now again from what I've been told due to the die shrinks that a modern chip, even something as old as the P3 or P4 would be hell to harden simply because its smaller dies and tighter tolerances would make it hell to protect from bit flips caused by cosmic rays, not to mention outright frying the chip from radiation exposure.
so are there any modern chips that would be easy to harden without being insanely expensive? Atom? AMD Geode? I'm sure with its GPU and dual cores Bobcat would be right out, maybe Via C3s? While ARM would be a good guess its die shrinks to fit in mobile phones would probably make it insanely expensive to harden yes? So while i'm sure the military probably bought a warehouse full of 386s before intel shut down what happens when they are gone? do we have a viable modern chip that withstand the rigors of space without costing insane amounts of money?
ACs don't waste your time replying, your posts are never seen by me.