MER Status Report Week Ending March 8, 2003

Every now and then you catch a lucky break. We caught one this week
that we still don’t completely understand, but we’ll take it. Our
Rock Abrasion Tool (also known as the RAT) uses diamond grinding
heads to wear away at martian rocks. Even though diamonds are the
hardest materials known, they can still wear out, and we’ve been very
concerned about how long the RAT grinding heads will last on Mars.
We’ve done a lot of testing in the laboratory, and it looked like the
RAT would do fine if martian rocks are soft. If the rocks turn out to
be really hard, though, it seemed that the RAT would make it through
just a handful of grindings before wearing out.

The big question, of course, was how things would work under the very
cold, dry, low-pressure atmospheric conditions on Mars. We put a RAT
into a test chamber recently, took it to real martian conditions for
the first time, and got a very pleasant surprise. The rate at which
our diamond-studded teeth wear away slowed way down! We’re still
figuring out why, but it turns out that when you put this martian RAT
into its natural environment, its teeth don’t wear down nearly as
fast. So we should be able to grind into as many rocks as we want to
on Mars, no matter how hard they turn out to be.