Printable Version of Topic

Posted by: Cugel Jun 22 2006, 09:08 AM

http://tweakers.net/nieuws/43129/Spontane-zelfontbranding-Dell-laptop-gemeld.html

Sorry for posting a link to a Dutch webpage, but it shows 2 images that pretty much speak for itself. It shows a Dell laptop that went into spontaneous self combustion mode. Note that these laptops use the same Li-ion battery type used on the MER rovers. Well, personally I think going out with a big KABOOM is a more appropriate ending to such a great mission than just fading away. I'm not implying that this will happen of course... just mentioning the possibility.

Posted by: climber Jun 22 2006, 09:45 AM

Yep, I like the idea of how we imagine could be an appropriate ending of such a mission. I realy don't like the plug out solution, I can accomodate with a rover been a lander because of the loose of mobility and I hate the fade away possibility. Soujourner was "ok" in the sense that we could imagine that the lander was the culprit, not Soujouner herself...hope she's still wandering around . I curious to ear the solution JPL will come up to give back some mobility to Spirit when spring will come.

Posted by: djellison Jun 22 2006, 11:38 AM

I quite like the idea of a rover dying by basically setting itself on fire in a fit of rage

Personally, I hope for the day where I can see images of one of these rovers sat on the surface wherever it ended its mission

Doug

Posted by: Pertinax Jun 22 2006, 12:34 PM

For those about who are less than poor at Dutch, the following translator may be of some help for getting a basic idea of the text: http://www.worldlingo.com/en/websites/url_translator.html

My apologies for a needless post if this is a well known resource.



-- Pertinax

Posted by: climber Jun 22 2006, 12:57 PM

I guess you mean shot by an astronaut.
I'm sure in this case it'll be a photograph not an image.

Posted by: Bob Shaw Jun 22 2006, 10:30 PM

It's entirely possible there's be a sudden POP! if either MER gets cold enough, then tries to recharge the battery after the electolyte gel freezes and warps the interior of the cells; whether or not the MERs could 'exist' as purely solar-powered stations without batteries I don't know - I suppose it'd largely be down to how the electrical engineers designed things. Phoenix, though, can hardly fail but to have it's battery trashed once winter sets in.

Bob Shaw

Posted by: helvick Jun 23 2006, 12:19 AM

I'm pretty sure the rovers cannot operate without functional batteries - AFAIK the failure mode of the battery cells is such that they fail open and all the other systems draw down from the batteries. I'd be very happy to learn that this was not the case from someone in the know however. So any expert out there reading who would like to delurk, please feel free to jump in.

There isn't much data available on the precise lifetime of the battery systems apart from preflight test requirements that listed 300 charge\discharge cycles for the battery subsystem and testing of the similar 2001 Surveyor batteries that showed they were capable of more than a thousand deep discharge cycles however recent updates to http://www.yardney.com/lithion/index.htmlseems to indicate that the MER batteries might be good for >2000 deep discharge cycles.

Posted by: mchan Jun 23 2006, 06:15 AM

Here is the article properly translated to English --

http://www.theinquirer.net/?article=32550