[meteorite-list] Mars Rover Spirit Restored to Health

From: E. L. Jones <jonee_at_meteoritecentral.com>
Date: Thu Apr 22 10:31:20 2004
Message-ID: <4020EA24.4010409_at_epix.net>

NASA doesn't want you to know that it may have gotten a
"virus"........e-mail or otherwise.(just kidding) MyDoom doesn't take
long to fill up any in box anywhere!

Actually, the memory, CPU and bus speeds are low, for amongst other
things I suspect, because they opted for EMP hardened military spec
chips. Those aren't as densely circuited as what we have today
commercially. Certification costs are very high and improvements don't
keep pace with commercially available chips. I think we were using a
microprocessor on par with the 386 recently on the shuttle orbiter. We
take things for granted today by assuming space hardened hardware is on
par with the latest "Plentimum Mk 8 Hyper10 Windblows 2010" . Be it
remembered we went to the moon with guidance computers less
sophisticated than a hand held calculator.

Good also that they are programed in a more widely used programming
language. Anyone know what the specs are for the onboard processors?
11k xfer rate is slower than a fax.

Elton

MexicoDoug_at_aol.com wrote:

>Thanks for the kind and informative answers in this and the other post, Ron ... At only 128 MB, that sounds surprisingly low ... it's pretty standard on a decent digital camera nowadays (and costs $100 or less, though I guess you have to keep it warm), that many dealers are sporting in Tucson. Also I can add that I recall reading, -don't remember where- that the data transfer rate (e.g., upload and download) for the communication netork / Rover is only around 11 Kbits per second ... if true, that's about one third the rate of a conventional land phone line (read one third of a dial up conection)... so maybe the memory isn't needed (128MB would take very near one Sol to transfer continuously assuming that were possible).
>
>Given the size of Flash Memory, I guess next time there could be an automatic backup safety parallel system that is activated by an independent signal. I.e. a reboot using a simple safety mode. Also, had the programming been in a lower level language, I wonder if the software crash would have been as likely to occur. But this is easy to sit back and contemplate now:)
>
>Saludos, Doug "Tucson" Dawn
>
>
>
>In a message dated 2/3/2004 9:02:21 PM Eastern Standard Time, baalke_at_zagami.jpl.nasa.gov writes:
>
>
>
>>
>>
>>>What type of operating system or machine language environment is being used?
>>>How many megabytes is the total flash memory's capacity?
>>>
>>>
>>The operating system is VxWorks, a real-time Unix operating system. It was
>>also used on the Sojourner rover. I've programmed on VxWorks before, and it
>>is a nice operating system, though I admit I have a Unix
>>bias. Most of the
>>rover's software is in C. The flash memory is 128 MB.
>>
>>Ron Baalke
>>
>>
>
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Received on Wed 04 Feb 2004 07:48:36 AM PST