[meteorite-list] Mars Exploration Rover Update - June 22, 2004

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Jun 23 12:26:59 2004
Message-ID: <200406231530.IAA26948_at_zagami.jpl.nasa.gov>

>
> Ron,
> I have a question about the Mars rovers. It is unbelievable how well
> they were engineered to not only complete the prescribed missions, but to
> over-extend the way they have been able to do. What is the ultimate limiting
> factor that will cause them to stop functioning? It seems like they have
> unlimited electrical, assuming that the storage cells are still able to
> re-charge from the solar cells. Is it the storage cells themselves that will
> fail first? Or are there other factors that will come into play soon that
> will end the extended mission?
>

If the rovers survive the Mars winter, then they have a good chance of lasting
several more months on Mars. In fact, when I last talked to Jim Erickson,
the project manager, he said they are planning for an 'infinitely long mission'.
Of course, a critical part on the rovers can go out at any time. The thermal
cycling from night & day is rather extreme. The dust accumulation
on the solar arrays is also a concern, as the available power will
drop with time. One of Spirit's front wheels just started to draw more power -
the first sign of age on that rover. Opportunity has had a heater
that has been stuck in the on position ever since landing.

What finally did Mars Pathfinder in was its battery. The battery was
charged during the day, and used at night to turn on the heaters to
keep the lander warm at night. When the battery finally gave out,
the lander was unable to keep itself warm, and after the first
night without the battery, the lander was never heard from again.

Ron Baalke
Received on Wed 23 Jun 2004 11:30:21 AM PDT