I am so rooting for the finding of water. I can't even begin to express the depth of my desire for the find. I'd love it even more if they continue to find "signs of life." I think the evidence so far is pointing that way (microbal of course) but I would love for this dig to really punch that idea through. I like the idea of a life-full universe. I think it's more statistically likely than not anyway, but that's me. :)
I still think my favorite HiRISE image is that of the lander still under the parachute. That really is rocket science.
I'd like to understand better the images of the backshell and parachute, and of the heat shield. The backshell and parachute appear to have been carried by the air in a 6 o'clock to 7 o'clock direction when the backshell impacted. That seems pretty clear from both the pattern of the discoloration and the position of the parachute.
But the heat shield looks more like it thumped into the surface and bounced off in the 2 o'clock direction. Which way would it have been moving relative to the ground, and the other parts of the craft? It would have been more ballistic, without as much influence by wind and no rocket-powered flight.
And, yeah, that sure does look like a creek bed! Spring thaw is going to be an interesting time...
Impact and landing sitessidelobeMay 29 2008, 20:20:03 UTC
The backshell and parachute appear to have been carried by the air in a 6 o'clock to 7 o'clock direction when the backshell impacted.
Yes. It seems to me that there are a several things going on.
The heat shield separated when the whole assembly was doing something like 900 miles per hour and was still miles up. The chute was intended to operate for only about 15 seconds, and was to slow it from about 900MPH to about 150MPH or so.
During that time, it might have covered perhaps two miles of distance. So the heat shield popped off two or more miles above ground, and its own velocity would have decreased rapidly as it's relatively light by itself (not much structure, and it was supported by attachment to the lander's underside and the upper surface of the aeroshell).
Apparently it slowed down (and curved more vertical) in a pattern very similar to the rest of the craft after separation. We know how big these objects are -- this pattern is close. I wonder if they were worried about landing on it? Or the parachute draping
( ... )
Re: Impact and landing sitessidelobeMay 30 2008, 01:00:15 UTC
I hadn't considered the mass of the heat shield. It probably has the aerodynamics of an aluminum foil pie tin. So maybe it followed the breeze just like the parachute did. I understood that it separated at 13km altitude, so it had a lot of time to flutter and flop around. (Maybe I have this part of the landing sequence backward, but wouldn't they want to separate the heat shield before the chute opens, to increase separation and reduce the mass to decelerate?) It's almost surprising it didn't sail, though the air really is pretty thin. I'll bet its fall was pretty well modeled at JPL, so I'm guessing they had probability ovals all laid out for the various parts
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Ah, but it's not just you. I'm inclined to think the same way.
I'm betting on Europa, though.
===|===============/ Level Head
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And, aw, shucks. Good to know I'm not alone. :)
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And I was just thinking of you in a different context:
Headlines on a Dark Knight
===|==============/ Level Head
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I'd like to understand better the images of the backshell and parachute, and of the heat shield. The backshell and parachute appear to have been carried by the air in a 6 o'clock to 7 o'clock direction when the backshell impacted. That seems pretty clear from both the pattern of the discoloration and the position of the parachute.
But the heat shield looks more like it thumped into the surface and bounced off in the 2 o'clock direction. Which way would it have been moving relative to the ground, and the other parts of the craft? It would have been more ballistic, without as much influence by wind and no rocket-powered flight.
And, yeah, that sure does look like a creek bed! Spring thaw is going to be an interesting time...
Reply
Yes. It seems to me that there are a several things going on.
The heat shield separated when the whole assembly was doing something like 900 miles per hour and was still miles up. The chute was intended to operate for only about 15 seconds, and was to slow it from about 900MPH to about 150MPH or so.
During that time, it might have covered perhaps two miles of distance. So the heat shield popped off two or more miles above ground, and its own velocity would have decreased rapidly as it's relatively light by itself (not much structure, and it was supported by attachment to the lander's underside and the upper surface of the aeroshell).
Apparently it slowed down (and curved more vertical) in a pattern very similar to the rest of the craft after separation. We know how big these objects are -- this pattern is close. I wonder if they were worried about landing on it? Or the parachute draping ( ... )
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