[X] My Assistant

[chris]

It would probably be less complex to make the solar arrays tiltable.

[Bill Harris]

Being a fellow engineer, I imagine the heatshield team must feel a small hint of sadness...

But look at it as the ultimate in destructive testing.

Great discussions here. Thanks!

--Bill

[djellison]

It does look like the whole thing is rippling a little in the breeze http://www.lyle.org/~markoff/collections/oppsol335R.gif

HOWEVER - remember - even over that short period the sunlight angle will have changed ( look at the shadow ) so it may be partly due to the sun moving a little - and partly due to wind

Doug

[MizarKey]

I favor the wind theory...check out how clean Opportunity is:



Eric P / MizarKey

[OWW]

It seems others are noticing the 'wind' too:

http://www.markcarey.com/mars/discuss-2174...stone-rock.html

Look at the 'movie' in the January 4, 2005 02:50 post by hortonheardawho.

[djellison]

It would probably be less complex to make the solar arrays tiltable.

Well- the actuators are almost there already to tilt the vehicle back and forward - so all that would be required is a means to command that specifically.

However - the next rover on mars will be RTG powered anyway

Doug

[chris]

Assuming, of course that the skycrane does its stuff (and I thought the MER landing were scary)

[djellison]

I didnt say succesfull lander - I just said lander

The last non-roving vehicle on mars wsa Beagle 2. It may be a small crater and some schrapnel - but it IS there

FWIW - I trust JPL to deliver with Sky Crane.

Doug

[djellison]

I was thinking about trying to reproduce this area in 3ds max - i.e. take bearings and ranges of navcam and pancam to reproduce a map that shows where everything is - then use that to build a 3d model of the debris on top of it.

Anyone got any thoughts on that?

Doug

[Guest_Sunspot_*]

I wonder if they are planning on getting a closeup look with the IDD at this rock:

http://qt.exploratorium.edu/mars/opportuni...BYP0725L0M1.JPG

Looks different to Bounce rock way back near Eagle Crater. That's an image from navcam, no pancam shots of it yet.

[MizarKey]

I was thinking about trying to reproduce this area in 3ds max - i.e. take bearings and ranges of navcam and pancam to reproduce a map that shows where everything is - then use that to build a 3d model of the debris on top of it.

Anyone got any thoughts on that?

Doug

With my limited cranial resources I can't be of much help , but I would love to see what you come up with.

Eric P / MizarKey

[Marcel]

I didnt say succesfull lander - I just said lander

The last non-roving vehicle on mars wsa Beagle 2. It may be a small crater and some schrapnel - but it IS there

FWIW - I trust JPL to deliver with Sky Crane.

Doug

Talking about MSL: Why didn't they include a small RTG on the MER's ? It is so amazingly valuable what they produce. The mechanical durability of the machines is known by all engineers: as long as energy is not the problem, the actuators, bearings and avionics can last muuuuch longer than 90 sols (which the machines BOTH proved). It would have been so cool to know that dust built-up is not going to be the problem. Consider what it would be like to know that even if the solar arrays would be full of dust, they still could go on (maybe on a slower pace due to the small nuclear source). Is such an RTG that heavy ? Can't they built small ones with like 0,5 kW of output ? Seems to me (considering the plans for MSL) that even rovers of 900 kg can be launched on a delta4.....so an RTG on MER could have been an option.
By the way: they are probably going to built TWO MSL's !! Wow, good idea !

[Guest_Analyst_*]

RTGs are better than solar arrays from an energy point of view, no doubt about it. But they are quite expensive, probably because so little are produced. And there is a lot of trouble because the general public often thinks all people in Florida will die from the radiation if the launcher explodes (I remember the Cassini launch in 1997). Also, maybe their radiation could spoil MERs instruments without protection.

One Voyager RTG has a mass of 39kg and generated 150W at launch, after 25 years abaut 100W. That's quite light for 2.400W/hr (!) per day (and night) after this long time. So MER could have used it. 39kg is about 1/4 of the total rover mass. But you don't need solar arrays! 0,5kW is really big.

Concernig the launcher: MER used a Delta 2, MSL will need a Delta 4 or Atlas 5, much larger rockets.

Analyst

[Pando]

Actually there are radioisotope units on board the rovers, eight of them, but they are used for heating and not power generation.

http://marsrovers.jpl.nasa.gov/mission/sc_...mp_heaters.html

Main reason is probably that the whole thing was designed as a unit, and it doesn't make sense to include an expensive, heavy power system to a rover that has other systems (wheels, gears, science instruments, etc) having less designed lifetime. In other words, to really make use of the RTGs, all other components must be designed to work for extended periods as well, increasing the cost and design time of the rover beyond what was budgeted and needed.

[jaredGalen]

In this image from the rear hazcam, in the middle track of the three wheel tracks shown, is that a hole near the left wheel?
It seems unlikely that a bit of stone got stuck on the wheel, and got plucked out of the ground seeing as it is lined up with one of the threads.

Or am I just looking at it wrong. It does look like a hole though.....

Edit: I guess it could be a piece of black material from the shield...but it still looks like a hole .

http://qt.exploratorium.edu/mars/opportuni...CLP1311R0M1.JPG