Technocrat

Phoenix Shake and Bake

zogger
Sat Jul 05 08:01:00 -0700 2008
Space+Flight
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The Martian Phoenix lander and analysis survey laboratory might be set for its final experiment after this weekend. The last sample looked at required so much vibration to break up the clumps that it has apparently damaged one of the ovens and caused a short circuit.

"Since there is no way to assess the probability of another short circuit occurring, we are taking the most conservative approach and treating the next sample to TEGA as possibly our last," said Peter Smith, Phoenix's principal investigator." Good luck guys!

ass-u-me in engineering

rubycodez
Sat Jul 05 08:37:30 -0700 2008
 manage

the sizing of the ovens and gratings were made by  bad ass-u-me, a lesson about engineering.

ass-u-me in engineering
Michael Smith
Sat Jul 05 14:28:34 -0700 2008
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Something for them to contemplate during their weekend off. They seem very relaxed for people operating a spacecraft with a life span limited to three months, and with experiments already failing.

ass-u-me in engineering
Beryllium Sphere(r)
Sat Jul 05 15:15:04 -0700 2008
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Weren't they based on existing data about Martian soils?

ass-u-me in engineering
Michael Smith
Sat Jul 05 15:40:20 -0700 2008
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Weren't they based on existing data about Martian soils?

The shaking grid thing worked in the end. Its just a shame that driving it this way is creating problems.

Their TEGA instrument developed a short circuit after shaking the sample for a longer than anticipated time. Now I can understand a motor which has been thrashed going open circuit. This seems to have happened to a wheel on Spirit and the shoulder joint on Opportunity after more than two years of operation.

But I don't see how something well designed can go short circuit. Did they melt the insulation on a cable? That doesn't even happen in my car. I know that mass has to be saved, and in a thin atmosphere some things can get very hot due to lack of circulation for cooling, but that should have been understood when they started operations. They could, for example, have run it 50% of the time to keep temperatures down.

Phoenix Shake and Bake
Bhima
Sat Jul 05 08:58:11 -0700 2008
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So here is the TEGA page. (complete with photos).

Having had to very, very occasionally wear similar getups working on instruments of similar size and complexity, I have to say I am glad I am not that man in the photo and I am glad I don't have to wear head / hair covering while wearing head mounted magnifying lenses.

 

So hopefuly everything works out for them!

 

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