I seem to recall a nasty cartoon around that time to the effect of.

Two astronauts hurtling to their doom and a tech on the ground with a kind
of Eureka balloon which said, Damn, I wondered what that extra set of
brackets did...

Brian

--
Brian Gaff....Note, this account does not accept Bcc: email.
graphics are great, but the blind can't hear them
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"Dac" wrote in message
u...
There are many different ways.

Some take pictures of objects, usually certain bright asteriods. There is
also a world network of recievers working like opposite to GPS.

Does anyone know how we navigate our deep space probes? I know we use
radar and GPS in LEO. What do we use for deep space? My guess is we use
Doppler shift a lot -- but that is just a guess.

My understanding is the navigation system of the probe that had the unit
conversion error was "telling" us that there was a problem, but we didn't
have enough confidence in the navigation system to realize there was a
catastrophic error in the trajectory.

Since the way they pass from one peice of software to the next and there
errors were all in that software as well no-one thought better.