Tuesday, July 5, 2016

Did Juno is a PowerPC?

Congratulations to NASA's Juno space probe team, which is now successfully in orbit around Jupiter. When you want radiation-hardened CPU designs (to guard against naughty things like cosmic rays flipping bits and zapping traces), you want BAE's RAD series, and that means you want ... PowerPC. Yes, Juno's brain is a lowly RAD750 running at 200MHz, essentially a beige Power Mac G3 with cojones of pure lead. It has 128MB of the baddest, meanest, toughest DRAM there is and 256MB of flash on board with a system bus providing 100Mbps of instrument bandwidth for pure awesome. The radiation around Jupiter, due largely to its intense magnetic fields acting essentially like gigantic particle accelerators, will expose the probe to the equivalent of a human getting 100 million dental X-rays in the course of a year (for me, that year was 6th grade); to enable it to survive its two year mission, NASA has encased the CPU and other critical components in a titanium box a third of an inch thick.

Remember: when you absolutely have to get to Jupiter, choose PowerPC. (Heck, Mars too.)


  1. You know, given PC specs these days... this probe is kind of funny. Look at how low that is, it's unheard of in this age.... yet it keeps on trucking.

    Put's things into prespective.

  2. That's neat. PowerPC was a good architecture for it's time. :)

  3. Bit-For-Bit (especially for multi-tasking) it will outperform ARM of much higher Geekbench scores.

    My DP MDD G4 comes in just shy of 1300 on Geekbench, but in porformance testing with TenFourFox rates above a Samsung Galaxy S4 on the Peacekeeper Browser Test - that Geekbenches over 3000 (congrats C.K.).

    And that is also considering that the G4 has a lot of other things going in the background/other apps running. Likewise, my Ouya (ARM Tri-Core/12-Graphic Core - Nvidia Tegra3) gets SLAUGHTERED by my MDD and its very old GeForce4 Ti on games found on both like Open Arena.

    If it were not such a power-hog, PPC would still be the king of RISC.

    1. To be fair, the company P.A. Semi did create a version of the PowerPC that consumed less than half the amount of power of the Core 2 chip. It also was much faster & produce much less heat that the Core 2.
      Unfortunately P.A. Semi's now producing ARM processors for the iPhone, Apple bought them out.

  4. Heh... I came here to post a "to be fair" post as well...

    So, here it is: To be fair, the Juno Mission's flight path was programmed to avoid the worst of the radiation, at least until the 36th orbit. It's all outlined in the trajectory design outline on spaceflight101.


    Scroll down to "Science Phase and Jupiter Orbit Design". Interesting stuff...


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