Jim Lux wrote:

...
It wasn't km and miles, it was pounds and newtons AND
the error was that Lockheed Martin supplied the thrust data in pounds,
unlike the contractual requirement to supply it in Newtons (which is
what we at JPL have used for decades). The error wasn't caught because
the absolute magnitude of the force is very small, so the differences
from predict to observation were on the order of the measurement
uncertainty. (We're talking measuring the velocity to mm/sec and range
to mm, when its at Mars.)
I'd venture that anyone would find measuring distances to 1 part in 1E12
challenging...
...

Damn, well someone told me, at work, told me it was a kilo/miles problem
.... however, the difference you state resulted in the same, apparent,
outcome--so sue me roflol

I must say, predictable!

Regards,
JS