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#120
by
jnc
on 08 Aug, 2012 18:13
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The SkyCrane "crater".
Just to make sure I understand, this is one of the exhaust-dug holes near the rover, not the impact crater, right?
Noel
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#121
by
Hungry4info3
on 08 Aug, 2012 18:14
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Yes.
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#122
by
Rocket Guy
on 08 Aug, 2012 18:14
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It wasn't heard wrong, that's what they said the other day (14:39). They have finally corrected it after being asked to, but not explained why they had it wrong.
I'd have to listen to it again.
They said something was 1014:39 but maybe it wasn't rover touchdown
or maybe it wasn't PDT but some uncorrected telemetry counter value?
They stated touchdown Mars time was 10:14:39, leading to lots of chatter about whether it was three minutes early, there was bad info, and other news sites reporting "10:39" as well. I believe the reporter asked today because they still hadn't clarified.
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#123
by
Pheogh
on 08 Aug, 2012 18:20
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I would love to know how the telemetry reconstruction is going and especially to actually see a sim of it. Anyone have any news about this?
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#124
by
Norm Hartnett
on 08 Aug, 2012 18:29
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#125
by
ArbitraryConstant
on 08 Aug, 2012 19:19
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Anyone have any news about this?
The one thing I caught from mission control during EDL was that when the heat shield popped, the radar velocity correction was 0.7 meters per second. I assume guidance until then was purely inertial.
Not my field, but that seems insanely good to me. They can probably work backwards from the initial radar fix and get very good position numbers all the way back to whenever they last got a fix from Earth.
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#126
by
asdyt
on 08 Aug, 2012 19:45
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#127
by
John44
on 08 Aug, 2012 19:50
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#128
by
go4mars
on 08 Aug, 2012 20:00
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Looks like a deflation lag to me (where it landed).
Also, I'm not a rocketry expert, but am surprised that the plumes had such a focussed effect on the ground so far below through near-vacuum. I figured the plumes would be more dispersed than that at that distance...
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#129
by
robertross
on 08 Aug, 2012 20:21
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Great view of the heatshield falling away, another full res frame that was downloaded from MARDI:
Super fantastic!
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#130
by
jcm
on 08 Aug, 2012 20:36
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It wasn't heard wrong, that's what they said the other day (14:39). They have finally corrected it after being asked to, but not explained why they had it wrong.
I'd have to listen to it again.
They said something was 1014:39 but maybe it wasn't rover touchdown
or maybe it wasn't PDT but some uncorrected telemetry counter value?
They stated touchdown Mars time was 10:14:39, leading to lots of chatter about whether it was three minutes early, there was bad info, and other news sites reporting "10:39" as well. I believe the reporter asked today because they still hadn't clarified.
Yes, the reporter asked today because I emailed him just before the press conference :-) - we go back a ways
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#131
by
iamlucky13
on 08 Aug, 2012 20:49
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So can we now cross off "unreasonable" radation levels on Mars for humans off the Mars Risk list 
...I believe that was one of the major unknowns......
The first graph isn't RAD data. It's sunspot counts for the last decade. The second graph (
link is an uncalibrated plot and has no units. It doesn't tell us much so far.
But the radiation environment has already been predicted through some fairly thorough analysis. It was not a complete unknown. We know it's quite a bit worse than earth - about 1,000 times the cosmic ray exposure, and I think about 100-200 times the total surface background exposure from all sources. This is the average rate, and it can jump significantly due to solar activity, so even though astronauts are allowed to receive up to about 75 times the annual exposure rate they would on the ground, you actually need more shielding than just what it would take to get your from 100x to 75x exposure. Mission design is for peak exposure, not average exposure.
I don't have a complete picture of the past dose assessments, but they generally seem amount to that the amount of shielding necessary is for the most part reasonable, but there is a moderate chance that a major solar flare can push the amount of shielding required to impractical levels.
The RAD data will show how well those predictions stand up to measurements, and provide a more confident basis for understanding how much protection astronauts actually need and what their total mission dosage would be.
In other words, excess radiation exposure is still considered a real risk, and the RAD instrument will likely confirm that. Note that this is primarily in the form of increased lifetime cancer risk. It should quite reasonably be possible to keep the exposure rate below what would cause radiation sickness, which would be a definitely unacceptable case.
Changing topics, here's a very roughly merged self-portrait mosaic from the navcam thumbnails:
http://mars.jpl.nasa.gov/msl/multimedia/images/?ImageID=4346
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#132
by
Robotbeat
on 08 Aug, 2012 21:05
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Comparing Mars surface radiation levels and Earth surface radiation levels isn't terribly helpful, and makes the situation seem worse than it is. There are places on Earth where people live long, healthy lives that have natural radiation levels comparable to low altitude areas of Mars.
Compare the levels of ISS and Mars surface. They are about the same in many places, and in places that are easiest to get to EDL-wise, (i.e. lower altitude), the radiation levels are significantly lower than ISS levels.
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#133
by
Norm38
on 09 Aug, 2012 00:02
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What I liked from today's presser at 25:20 was that it's basically set that the rover is safe to drive. No obstacles nearby to worry about.
A drive to one of the thruster craters is probably first.
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#134
by
marsman2020
on 09 Aug, 2012 07:56
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A bunch more full resolution NavCam images from Sol 2 are now posted in the raw images section.
I couldn't help myself, I stitched a few of them together to make this. I also spotted a few other bits of hardware that I worked on in addition to the dust covers.
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#135
by
Bogeyman
on 09 Aug, 2012 07:58
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Great work, marsman! Looks like there is some grain on the deck
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#136
by
Bogeyman
on 09 Aug, 2012 08:03
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What was in these white "trays" that you can see just a little left of the center of the image?
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#137
by
ugordan
on 09 Aug, 2012 08:34
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#138
by
robertross
on 09 Aug, 2012 11:27
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A bunch more full resolution NavCam images from Sol 2 are now posted in the raw images section.
I couldn't help myself, I stitched a few of them together to make this.
very nice, thanks
I also spotted a few other bits of hardware that I worked on in addition to the dust covers.
Please, do tell!
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#139
by
Chris Bergin
on 09 Aug, 2012 15:25
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Heads up that I can't be around at the time of this next presser, so if everyone could chip in.... thanks!
...I believe that was one of the major unknowns......