NASA's Phoenix Mars Lander Killed By Ice 113
coondoggie writes "NASA officially ended its Phoenix Mars Lander operation today after a new image of the machine showed severe ice damage to its solar panels, and repeated attempts to contact the spacecraft had failed. 'Apparent changes in the shadows cast by the lander are consistent with predictions of how Phoenix could be damaged by harsh winter conditions. It was anticipated that the weight of a carbon-dioxide ice buildup could bend or break the lander's solar panels. [Michael Mellon of the University of Colorado] calculated hundreds of pounds of ice probably coated the lander in mid-winter.'"
Re:Too bad they didn't use RTGs. (Score:5, Interesting)
A. It wasn't a rover.
B. They knew that this would happen.
C. The only reason they didn't use RTGs was because of cost and the nut cases that would protest the launch.
I know why they used solar. It was good enough for this mission.
But it would have been really interesting if they where given the budget to use an RTG and had kept gathering data over the winter.
So no knuckle head I was not criticizing their skills. Just lamenting that the mission was so limited in scope.
Re:What? (Score:2, Interesting)
Frozen CO2 as "ice" makes as much sense as frozen iron as "ice".
Actually, it makes as much sense as frozen water as "ice". Anyone who thinks otherwise is simply not as fluent in the English language as they could be. Someone who isn't as familiar with the language is likely to try to puzzle out nonexistent rules because they aren't familiar with the linguistic conventions that apply in the case at hand. But those who are familiar with how the language is used know that "ice" is a word that applies to certain cases of solids without regard to their chemical composition. Indeed, the word "ice" long predates the knowledge that water ice composed of H2O, or that dry ice is composed of CO2. To assert that "ice" means "solid H2O" shows vast ignorance of the historical usage of the word.
Re:What? (Score:3, Interesting)
I cannot think of any time anyone would use the word ice (alone without adjectives) to mean anything else, save for completely unrelated slang. Educate me....
I can't think of any situation on Earth where "ice" would be used to mean anything but water ice, since everything else requires such otherworldly conditions. NASA scientists are a bunch of space cadets. Speak English not Martian!
Hintedy hint. :)
But seriously, it's not like they didn't specify at any point in the article that they meant CO2 ice. If you've ever heard the term "Martian icecaps", then you've heard ice used to mean not-water ice (even though there is some there, but we didn't always know that).
Re:Too bad they didn't use RTGs. (Score:3, Interesting)
more complex? How? the RTG is a very simple device.
Your analysis is 100% correct assuming the REST OF THE MACHINE could function for years without any increase in complexity and weight. My guess is no. Yes a radio that operates "forever" costs about as much as a radio that operates for a couple weeks. I'm not completely familiar with the science instruments onboard, some things like magnetometers operate "forever" but some things like gas analysis systems complete with reagents and vacuum pumps and purge gases have a very finite life. Optics get covered with dust, unless you add a heavy system to clean them. Stainless steel ball bearings in a windspeed meter will eventually wear out, unless you do something heavy and complicated.
Wasting all that money on an expensive RTG isn't so useful if all you end up with a year later is a working radio and ... not much else. Maybe a working seismometer and a working magnetometer and everything else used up and worn out? Interesting, but maybe not worth the bucks.