Tomorrow, the first of the American rovers lands on Mars. Ed Weiler, the
Associate Administrator for Space Science at NASA, and someone who I tend to hold
in high regard, has called Mars the "Death Planet" simply because so many
lander attempts have failed in the past. At the moment, the failure rate is about
70% -- and potentially climbing.

The Mars Exploration Rovers are the most complicated machines yet sent to
Mars. NASA/JPL has put up two really nice movies about what will happen tomorrow
and over the next week. The two events are called Entry, Descent and Landing
(EDL) and Impact to Egress (ITE). If you have an even reasonably high-speed
connection, the movies are certainly worth watching. The first movie is at:

      http://marsrovers.jpl.nasa.gov/gallery/video/challenges.html#edl

and the second (broken into two parts) is a little further down the page.

Every action taken during the EDL phase has to be done automously, by
computer. EDL will take the spacecraft from a speed of 12,000 mph to essentially
zero, in a space of six minutes, thus NASA calls the first movie "Six Minutes of
Terror." No commands from the earth are possible, simply because Mars is now
out about 10 light-minutes roundtrip ping time.

While the first landing occurs tomorrow, it will probably be about a week
before the MER rolls off of its landing pad and onto the surface of Mars, if it's
successful.

Wirt Atmar

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