

Hayabusa-2 probe uses 64-bit MIPS CPU to explore the origins of the solar system - alexvoica
http://blog.imgtec.com/mips-processors/back-to-the-future-64-bit-mips-cpu-explores-rare-asteroid

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hga
Google helped me find this very detailed article on the probe:
[http://www.spaceflight101.com/hayabusa-2.html](http://www.spaceflight101.com/hayabusa-2.html)

Which says the solar panels are designed to produce 1,400 watts at the
furthest distance from the sun. So it gets this 200 Mhz 64 bit MIPS chip,
whereas the ~200 watts at Pluto New Horizons uses a 12 Mhz 32 bit MIPS chip
(and the power gets steadily lower as it heads out and hopefully looks at a
Kuiper belt object).

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Someone
I don't know anything about architecture or power usage of these CPUs, but it
wouldn't even surprise me if that 200MHz CPU took less power than that 12 MHz
one.

There also is a window of almost 9 years between the launch dates of these
systems (January 2006 vs December 2014)

That's six times the 18 months of Moore's law, or a factor of 64, so it could
explain much of the difference.

~~~
alexvoica
Maximum TDP for HR5000 is 4-6W (fact) whereas the Mongoose-V might be in the
sub 1W range (speculation).

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Symmetry
I wonder how the radiation protection process works?

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bsder
Nowadays, mostly architectural. Some design. Not as much process.

They call it "hardening-by-design" which translates to "not rad-hard, at all,
just fault tolerant"

Architecturally, you put in a lot of fault tolerance. Multiple oscillators so
you don't lose lock. More ECC for RAM. Modulo checks for arithmetic. The
ability to reboot quickly and get back to operational from a checkpoint is
useful. Voting on operations to detect failures.

Design-wise, you minimize nodes that can cause upsets. You put more charge on
gates and only use static CMOS. Presumably, you use bipolar (which is current-
driven rather than voltage driven like CMOS) anywhere you can without losing a
lot of area (PLL's, I/O's, RF, analog circuitry).

Process-wise, insulating substrate is the obvious thing since it minimizes the
collection of ionized charge. I doubt they do much more. Developing stable
materials for semiconductor usage is _really_ expensive, and not terribly
profitable.

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alexvoica
For anyone still reading this, I'm interviewing the JAXA engineering team this
week. If you have any specific questions you'd like me to ask, reply to this
comment.

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gaius
For real work you want MIPS or SPARC, Intel just don't cut it.

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akuma73
May I ask why?

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gaius
Easier/more efficient to program in stack-based languages like Forth, lower
power consumption, simpler designs are easier to radiation-harden, and more.
Why do you think no-one uses Core i7 in space?

Dunno who downvoted me, some fanboy probably. Nevermind I got karma to burn.

