Seen on RISKS-L

From: William Donzelli <aw288_at_osfn.org>
Date: Thu Mar 7 18:03:21 2002

> I thought I read the Mars lander machine readable data was lost
> from 1976? because the format the data was saved in was not documented
> and the programmer on the project died, and the computer used was
> scrapped.

No. Funny that you mention the Viking mission - one of the guys at RCS
has the actual tapes. Plain ol' 9 tracks.

The thing that might have been the seed for all of this "NASA lost data"
mythology is that the original telemetry tapes may be gone. When anything
was launched by NASA (or the military), the telemetry receivers would
record the information in analog format - the video coming right off the
receivers. This was done so the data was recorded in real time,
reduntantly, even if a computer crashed - the "dumb" tape decks would
record regardless of the world around them. Only later would the analog
tapes be read and converted into digital data.

Telemetry tape drives, as with most lab grade tape drives, were built to
a number of standards, some of which died off and faded into obscurity.
NASA, however, was smart enough to covert the data into a far more stable
format before the telemetry tapes would have decayed. I would not be
suprised if it was only hours after the data came back to Earth.

William Donzelli
aw288_at_osfn.org
Received on Thu Mar 07 2002 - 18:03:21 GMT