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The Ancient Computers Powering the Space Race
An anonymous reader writes "Think that the exploration of space is a high tech business? Technology dating back to the Apollo moon landings is still used by Nasa mission control for comms and the 1980s 386 processors that keep the International Space Station aloft."
The Ancient Computers Powering the Space Race
From general agreement on the definition of the Space Race:
The Space Race was a mid-to-late twentieth century competition between the Soviet Union (USSR) and the United States (USA) for supremacy in outer space exploration. The term refers to a specific period in human history, 1957-1975, and does not include subsequent efforts by these or other nations to explore space.
Emphasis mine. As to the 'ancient tech', it's stable and still working so what's the problem? People are bitching about rising taxes not the fact that we are stunting ourselves in exploring space. It's not 1975 anymore, people have moved on to other international penis/rocket/missile envy matches.
In related news, the house fails to agree on a meager NASA funding bill while space tourism continues to progress.
My work here is dung.
Those "ancient" 386 chips are probably mil-spec radiation hardened chips, too. Good luck getting your 45nm quad cores to work reliably in space...
No sig today...
And the B-2 Stealth bomber has the equivalent of an Amiga 1000 running it. What is the point of this article? Critical systems require reliable, proven, hardened hardware, not flakey netbooks.
If they are not the fastest CPUs, who cares? They aren't playing half-life on these systems they are flying space shuttles, and if you can't tell the difference, do not work in the defense or space industries. CPU speed isn't the prevailing factor here, reliablility and a known/proven system is.
If telephones are outlawed, then only outlaws will have telephones.
I forget which sci fi author it was, but there is a book where one of the main characters is hired to analyze code of a failing satelite. And he says "Perhaps the cleanest most boring software he had ever seen, virtually bug free, and what bugs there were had 3000 pages of documentation."
The Revolution Will Not Be Televised
My first engineering job out of college was as an avionics engineer at McDonnell Douglas in 1996. We were designing avionics using a Highly Reliable Industrial (HRIP) M68000 CPU downclocked to a couple of MHz. The reason for this CPU choice was that it did exactly what was required for building an embedded system. Also the M68000 had/has a very long production cycle and would be around for many years to come, which is important if you need spare parts in the future. We used the minimum clock setting required to achieve the required performance and to reduce power consumption and thermal cooling requirements. Modern general-purpose desktop CPUs normally aren't good choices for single-task embedded systems because of their power consumption, short product life spans, and general feature overkill. You do not need a particularly fast CPU to perform basic guidance and control tasks or to run avionics computers. The PowerPC has been adapted for imbedded MILSPEC systems for example and it's about 10 years behind the "state of the art."
I'm not surprised, not at all. The A320 ELAC uses 3 68k chips, and the A320 SEC uses an 80186 and even an 8086 chip. Why? For lots of reasons. Basically, it doesn't require billions of instructions per second, it doesn't need to access gigabytes of memory, and most importantly, they are proven chips that have gone through years of testing, and they are relatively simple. At the time they were complicated, granted, but they were still within reach of severe quality control. Remember the problems Intel had with the Pentium and floating point calculations? Nothing serious, but still... The chip was so complex that problems crept into the design phase, and at 38000 feet, you do not want problems. To cite a fellow Slashdotter above, (thanks tekrat), Critical systems require reliable, proven, hardened hardware, not flakey netbooks. Enough design faults have crept into aeronautical design, so I can only imagine the space sector. NASA used to program everything in 68k because they were reliable, simple, fast enough, and because they had lots of really, really good engineers that knew every single aspect of the chips. Don't get me wrong, I love todays chips, and i7s look sexy, but with a TDP of 130W for the Extreme Edition chips, they just add problems. Running at 3.2GHz, with over a billion transistors, you are just asking for trouble. At those speeds and heat, problems do happen, the system will crash. Ok, not often, but with mission critical systems, just once is enough. Did anyone seriously expect the shuttle to run quad-cores with terabytes of RAM?
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The last 20MHz RAD6000 flight board we bought was around $250k. A flight FPGA runs about $5k each. 10 times is actually quite an understatement for radiation hardened.
Largely this is a function of geometry. The smaller gates required for higher speed operation are also vastly more sensitive to imparted charge from ionizing radiation. Large slow chips are inherently more robust, so when you do things like Si on sapphire you get a lot of bang for your buck.
I don't doubt that a fast core could be RAD hardened, but the current generation of Core2 arch and ix arch from Intel/AMD/IBM are virtually impossible to make into a rad hardened build. You really would need to do a redesign with things like ECC registers and the demand for such chips is so low as to not be a profitable endeavor for any of the main players. Demand is satisfied by the RAD600/750 families (PowerPC 750 / Apple G3), so why invest gobs of money into R&D for a product that has little to no demand?
-nB
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