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MSL Post Landing - Commissioning Period & Early Observations, Commissioning Activity Period 1B - Sols 9 through 16
dmg
post Aug 23 2012, 12:30 AM
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QUOTE (Ondaweb @ Aug 22 2012, 04:06 PM) *
Any ideas where else I might find a replay of today's (8/22/12) press conference? I hate to miss one.


See: http://www.ustream.tv/recorded/24889670
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MahFL
post Aug 23 2012, 12:31 AM
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Replay

This works ok for me.
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Ondaweb
post Aug 23 2012, 01:29 AM
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Thank you both, it's working.
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jmknapp
post Aug 23 2012, 02:00 AM
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QUOTE (Paolo @ Aug 22 2012, 03:41 PM) *
hydrogen was only found on the first shots to Coronation, so it must be a very thin surficial layer. I was wondering: could this be contamination from hydrazine (N2H4) from the Skycrane exhausts?


Check out this paper:

Biological effects of fuel and exhaust components from spacecraft descent engines employing hydrazine

QUOTE
One of the objectives of the Viking mission is to determine the existence of extraterrestrial life on the Martian surface. A retrorocket engine powered by catalytic decomposition of hydrazine fuel will be employed to soft-land the scientific instrumentation on the surface of Mars. It was imperative, therefore, to determine if hydrazine and its breakdown products in the engine exhaust would affect organisms at the sampling site. ...

In the final approach of the Viking lander on Mars, the retrorocket engine to be used is powered by a catalytic decomposition of hydrazine fuel to gaseous products by a stochiometrically undefined process of the type:

(2a+b)N2H4 -> 2aNH3 + (a+2b)H2 + (a+b)N2

It was estimated that at the landing site NH3, the major product, might reach fleeting concentrations of approximately 30 percent of the Martian CO2 atmosphere. In such an atmosphere, the reaction also generates aniline, hydrocyanic acid, and in all probability carbazic acid (H2NNHCOOH) and ammonium carbamate (NH4OOCNH2). Further work by Martin Marietta Corporation and others confirmed that the products depended on the grade of fuel used and the nature of the atmospheric environment. Purification of the "mil spec" hydrazine fuel lowered the yields of the decomposition side products, especially HCN. Nevertheless, it appeared that HCN at levels of 200-500 ppm might be encountered in the atmosphere at, and immediately surrounding, the Martian landing site. The possibility also exists that hydrazine fuel could contaminate the landing site by lander tank leakage, by unreacted N2H2 in the engine exhausts, or by the impact of the deorbit propulsion tanks with the aeroshell.


Maybe Curiosity oughta just mosey on? ;)


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stewjack
post Aug 23 2012, 02:53 AM
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QUOTE (jmknapp @ Aug 22 2012, 09:00 PM) *
Maybe Curiosity oughta just mosey on? wink.gif

I expect this question will be answered as we mosey on.

Chemistry & Camera (ChemCam)
http://msl-scicorner.jpl.nasa.gov/Instruments/ChemCam/

Under Types of Investigations
3. Soil and pebble composition surveys. The ChemCam team plans to make a measurement of the soil near the rover each sol to document the range of soil compositions over which the rover traverses. These measurements may signal the presence of a new geological region, and will tell about the compositional similarity of the dust from place to place on Mars.
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3d_mars
post Aug 23 2012, 05:29 AM
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There appear to be parallel lines of pebbles that are very apparent when viewed in 3D. Both left and right images contain the same features. Does anyone else see what I'm trying to point out?

Attached Image

Attached Image
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Astro0
post Aug 23 2012, 06:43 AM
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My feeling is that this is an optical illusion akin to pareidolia.

Attached Image


Take a look at this image of random dots.
You will see dark and light lines running parallel, crossing, merging etc.
Yet they are completely random points.

As the rover moves, this scene will change and the lines will seem to follow another set of rocks.

I'm sure that someone with much better knowledge about these things will have a better explanation, but that's my take on it.
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Harder
post Aug 23 2012, 08:18 AM
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Reading up on ChemCam as suggested by Stewjack: done. Also read the next item (APXS) and now I wonder: what is the specific scientific deliverable of APXS relative to what ChemCam will be able to do? It appears such an obvious question, both do elemental analysis after all, but I have not been able to google a document that clarifies this. Selection of payload is not a trivial matter so I'm sure I overlook something pretty important..
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ugordan
post Aug 23 2012, 09:10 AM
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Couple of Mastcam-100 frames are down:

http://mars.jpl.nasa.gov/msl/multimedia/ra...1_DXXX&s=13
http://mars.jpl.nasa.gov/msl/multimedia/ra...1_DXXX&s=13

The rest, looking toward Mt. Sharp are blurred:
http://mars.jpl.nasa.gov/msl/multimedia/ra...1_DXXX&s=13


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MahFL
post Aug 23 2012, 09:12 AM
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QUOTE (Harder @ Aug 23 2012, 08:18 AM) *
Reading up on ChemCam as suggested by Stewjack: done. Also read the next item (APXS) and now I wonder: what is the specific scientific deliverable of APXS relative to what ChemCam will be able to do? ....


It was explained on the last news conference, APXS is more accurate, but ChemCam can sample many rocks pretty quickly but with good results, then they'd follow up with the other instruments on "interesting" targets.
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xflare
post Aug 23 2012, 09:42 AM
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QUOTE (ugordan @ Aug 23 2012, 10:10 AM) *
Couple of Mastcam-100 frames are down:

The rest, looking toward Mt. Sharp are blurred:
http://mars.jpl.nasa.gov/msl/multimedia/ra...1_DXXX&s=13



Parts of this one look sharper...I think http://mars.jpl.nasa.gov/msl-raw-images/ms...3000D1_DXXX.jpg

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chris
post Aug 23 2012, 10:32 AM
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QUOTE (ugordan @ Aug 23 2012, 10:10 AM) *
The rest, looking toward Mt. Sharp are blurred:
http://mars.jpl.nasa.gov/msl/multimedia/ra...1_DXXX&s=13


I know the mastcams can focus, and have autofocus. I've looked, but I can't find any information about how the focus is controlled. Do we get an out
of focus image because the camera is commanded to take a picture but the autofocus is turned off? Or was the focus distance set from JPL but to a value
that meant the image is blurred?

Chris
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jmknapp
post Aug 23 2012, 11:13 AM
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More background on possible landing site contamination:

Preventing the Forward Contamination of Mars, By National Research Council (U.S.). Committee on Preventing the Forward Contamination of Mars

QUOTE
The first and only known assessment of landing site contamination from rocket exhaust gases was performed experimentally, during the development of the Viking lander... During the assessment, engineers changed the descent engine nozzle design (which was subsequently used on the Viking landers) to diffuse the gas and reduce soil erosion as the lander approached the surface. The results of chemical analysis of the soil samples showed measurable amounts of hydrogen cyanide (HCN), which were traced to aniline impurities in the Mil-Spec fuel. Switching to a purified hydrazine fuel eliminated the unwanted HCN, and that fuel has since been the standard for all subsequent Mars soft landers to date, although tests also showed that the purified hydrazine would contaminate Mars landing sites with ammonia (50 to 500 ppm), N2 (5 to 50 ppm), and possibly a small amount of water (quantity not measured). The large amounts of ammonia trapped in the soil would make interpetation of organic analyses more difficult. ...

The rocket exhaust study conducted for the Viking mission also addressed gas dissipation from the soil after landing (actually release and diffusion)... The Viking Molecular Team set as criterion that exhaust gas contamination at a concentration above 10ppm be permitted to exist for no more than 2 days after landing...

No subsequent comprehensive analyses for retrorocket contamination have been performed. The Viking assessment results have served as the ad hoc basis for all subsequent NASA soft-lander missions...

The [MSL] sky crane is expected to use hydrazine retrorockets as did Viking, but it may have throttled engines rather than pulsed engines, which would reduce potential disturbances of soil. Nonetheless, the sky crane will require larger loads of hydrazine propellant for their payloads (200 kg compared with 85 kg for Viking) and will at least temporarily contaminate the atmosphere surrounding the landing site.


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xflare
post Aug 23 2012, 11:29 AM
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QUOTE (chris @ Aug 23 2012, 11:32 AM) *
I know the mastcams can focus, and have autofocus. I've looked, but I can't find any information about how the focus is controlled. Do we get an out
of focus image because the camera is commanded to take a picture but the autofocus is turned off? Or was the focus distance set from JPL but to a value
that meant the image is blurred?

Chris


Im sure that at last nights media briefing they said the mastcam 100 still had to be commissioned/tested properly, and these images were taken quite a few sols ago on sol 13.
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climber
post Aug 23 2012, 11:58 AM
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QUOTE (xflare @ Aug 23 2012, 11:42 AM) *
Parts of this one look sharper...I think http://mars.jpl.nasa.gov/msl-raw-images/ms...3000D1_DXXX.jpg

Do you see several sort of land slides near the center? (no, I didn't say gullies)


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