MER 2003 Update Week Ending August 31, 2002

It’s alive! Our first rover arm has been delivered, and it’s working
beautifully.

Each MER rover will carry a robotic arm that we’ll use to position
four of our scientific instruments: the Microscopic Imager, the APXS,
the Moessbauer Spectrometer, and the RAT. The arm is the same size as
a human arm, and like a human arm has a shoulder, an elbow, and a
wrist.

Our first flight arm — one of the ones that’s going to Mars —
recently arrived at JPL, and we’ve been putting it through its paces.
We haven’t put any of the instruments on it yet, though that’ll
happen soon. What we’ve done this past week has been to mount the arm
on a rack, hook it up to the rover’s electronics, and start seeing
how well it moves. The real question on our minds has been how well
the arm will be able to position the instruments, and the preliminary
answer seems to be very well indeed. We still have to actually mount
it on the rover body and run it at real martian temperatures, but all
the indications so far are that it will be able to put the
instruments where we want them every bit as accurately as we had
hoped, or maybe even better.

And on top of that, it’s really something to see as the arm moves all
its joints and reaches out toward some imaginary martian rock. It’ll
be doing the real thing soon enough.