That's a little harsh. To be fair - he IS the principle investigator. He lead the development of the instrumentation on this thing - the buck stops with him. But it's not right to say that just because two people here disagree with what he wants to look at, then he must have the final say on everything. It's quite likely that many members of the science team want to see Vostok. It'll be interesting to characterise it simply as another ground-truth for MOC imagery if nothing else. It looks odd - it isnt neat and round, it has a fragmented rim - and it's 1km south of the main sites of investigation and given that Meridiani is on a gentle down slope heading south ( 2 deg I believe ) - then it may be strata we've not seen before. And one has to break up periods of long driving with periods of scientific investigation if for no other reason than to maximise the data volume sent back (fill flash, then drive for 6 days and downlink it all- repeat )

Doug

Well - thats the thing - we can get to Vostok in fairly short otder and then see what it's all about. It looks larger than Eagle by about 50% - and might be easily accesable. We'll be there in two weeks at this rate.

Doug

"at most 15 minutes of available post-landing communication with the orbiter"

ARHGHGHAH

Ironically, a screw up forces a resdesign which gave us >6 times that. I wonder, if they'd have known about the dopper issue during PDR - would they have redesigned the misison as they have, or fixed the doppler issue's engineering. And if the former - would they then have considered some sort of modifications to instrumentation for the possibility of extended surface operations.

Doug

Umm - actually -yeah, I think so. 150+150+80 - 380 metres - further than that crater I believe

Doug

http://www.jpl.nasa.gov/missions/mer/fligh...28-Jones-T1.mov

They got 154 metres on the long drive, and are planning a similar length drive today



300m in 2 days

Obviously a LOT of crater hoping and stop-offs en route - but at that rate, they could actually cover the ground to Victoria in, hell - 8 working weeks

That deserves

Doug

yup

Doug

Argo is the JPL name for Green Crater

Doug

"For a rover vertical solar
array, the dust obscuration rate was assumed to be much smaller than that for a horizontal array." (Thank you GL )

Assumed....not measured fwiw, looking at the sundial, I'm fairly sure that a vertical array would collect as much dust as a flat one - but a vertical array may be more condusive to 'shaking' the dust off over rough terrain

Compressed air = heavy system of tank and thus expendable, or a heavy compressor and thus you sand-blast the arrays with fines.

iirc - Polar Lander (or perhaps it was the orig '01 design) had a small array on the side that was configured to reject dust electrostatically.

The long term answer to using solar arrays on mars is very simple.. Use RTG's

As for the comparative images - yeah - scattering might be different - but, the shadows are roughtly the same intensity, the azimuth of the illumination may be different, but the elevation's about the same - I think it's fair to say that the images are a valid before and after comparison. What would be interesting is seing if driving over rockier terrain on a slope might dislodge some of this.


D

Really? The air on mars may be thin - but it's there, and has wind - and the dust it carries is quite 'clingy' - and imho, it is the side of things that should get dustier first as the dust doesnt 'fall' out the sky, it drifts with the air flow. Infact, you could tell the prevailing wind at Gusev by the side of the sundial the dust stuck to after the first dozen days on the lander If the horez. surfaces should be dustier than the sides of surfaces - then how can you explain the rocks on the ground at gusev - many have a dusty upwind side and a less dusty downwind side. The same is true of pathfinder - infact Yogi is a prime example - v.dusty on the left - much darker on the right. You can see it on the earliest pictures of the black mast - dust up one side much faster than it gathers on the top.

Put it this way - when its raining, you windows get wet as WELL as the floor, and in a blizzard, the snow hits your windows and melts a lot quicker than it lands on the floor.

The colours demonstrated in those images are not exagerated - and imho, instead of being sadened by the state of Spirit - it's grounds to celebrate and rejoice in the fact that DESPITE all that dust, the damn thing's still working And imagine how long Opportuinty would have to spend at Meridiani to get that dirty Those images say to me - look - despite all this, they still work, so you can expect a whole lot more to come yet

Doug

PS - to celebrate, the wheel emoticon now rotates

It's. umm...

a mars thing



Doug

There is azimuth data in the header for each -img file in the pds but not for the jpg releases.

I'm fairly sure that's Victoria - it's just about the right size w.r.t pixels. It may be that it doesnt have particularly high crater walls - at this distance it doesnt look like it has any at all - but it is 6k away

Doug

Yup - I'm looking at PDS stuff form Sol 121 and 122 - will report back as and when i have any luck finding something. With L2 it SHOULD be very clear - but it isnt

Doug

Yup - that's exactly what it is

Doug

That was the point in doing the maths to calculate at what range the rover would first see something of 1, 5, 10, 20 metres high appear over the horizon.

Victoria is big. Very big. Now - if it's say 1/20th as tall as it is wide - thats 35 metres

Lets say we need half of that to appear over the horizon before we 'see' the crater

So - 16 metres should be visible form a range of 19km, the crater would be 132 pixels wide, and that 16 metres perhaps only 3 pixels tall.

Tip - use L2 filters to look for it - they bring out rock outcrops as very very very bright -

( http://marsrovers.jpl.nasa.gov/gallery/all...30P2213L2M1.JPG of endurance for instance )

Now - to be honest - I'm astonished we've not seen it yet - especially from the heigh advantage given to us at Pan Position 2 ( sols 122ish )

Doug

Etched terrain starts about, erm well. - from the heatshield...

'Green' Crater - 220 m
Vostok Crater - 1100 m
Very closest obvious etched terrain - 2200m SW
Subtle Etched Terrain - 2600m S
Large 'crater like' etched terrain feature - 3500m SSW
'End' of etched terrain before Victoria Crater - 5400m S
NW rim of Victoria Crater - 5600m S
S rim of Victoria Crater - 6400mS

Distance from Eagle to Endurance. - 700m


Other stats....
Diameter of Victoria Crater EW - 715m
Diameter of Victoria Crater NS - 770m
Diameter of Victoria Crater central dune field - 270-300m
Width of Victoria Crater NW 'entrance ramp' - 30m
Width of Victoria Crater W 'entrance ramp' - 60m
Diameter of crater-like feature in etched terrain 320m
As the Crow Flies - Eagle to Victoria - 6600m
Diameter of Eagle Crater - 25m
Diameter of End Crater - 170m
Diameter of End Crater Dune Field - 40m
Diameter of Vostok Crater - 30-50m

Sizes
Scaling factor - Eagle to Vostok Crater - 160%
Scaling factor - Eagle to Endurance crater - 680%
Scaling factor - Eagle to Victoria - 2920%
Scaling Factor - Endurance to Victoria - 430%

Angles
715m crater width in pixels
Range : Pancam : Navcam
6000 : 425 : 156
3000 : 856 : 315
1500 : 1770 : 650

Technically - Victoria should be fairly obvious at this range - however - Mars is quite a bit smaller than earth - distance to Horizon = 83.38 X height^.5

Pancam height is 1.54m - thus horizon is about 3.27km away - so we will not see Victoria for some time to come with MER.

With Hazcam, the horizon is approx 1.9km away

Bottom line - we'll need to travel about as far south from Vostok as Vostok is south from Endurance before we see Victoria - unless it's really really tall
Height (m) Visible from (km) Pixel Width of 720mCrater
0 | 3.27 | 784
1 | 4.27 | 599
2 | 5.27 | 484
3 | 6.27 | 407
4 | 7.27 | 351
5 | 8.27 | 308
6 | 9.27 | 275
7 | 10.27 | 248
8 | 11.27 | 226
9 | 12.27 | 207
10 | 13.27 | 192
12 | 15.27 | 167
14 | 17.27 | 147
16 | 19.27 | 132
18 | 21.27 | 120
20 | 23.27 | 109
22 | 25.27 | 101
24 | 27.27 | 93
26 | 29.27 | 87
28 | 31.27 | 81
30 | 33.27 | 76
35 | 38.27 | 66
40 | 43.27 | 59
45 | 48.27 | 53
50 | 53.27 | 48
60 | 63.27 | 40
70 | 73.27 | 35
80 | 83.27 | 31
90 | 93.27 | 27
100 | 103.27 | 25


Doug

six months later....

Not sure when they've driven and when they've not. I THINK, looking at navcam - they drove did the 80m drive straight after the final MI sequence on the heatshield - then perhaps because of a restricted sol or something - didnt drive, and then tonight it'll do the big drive

Notice the quite long delay between frames on this end of 80m drive sequence..

http://qt.exploratorium.edu/mars/opportuni...cam/2005-01-25/
I was going to suggest that the long 3 minute gap between frames might be a symptom of multi-spectral imaging, but no - looking back - it's normal for the end of sol L7/R1 3x1 mosaic


Doug

Well - the parallax calculator puts the 'big piece' as 81.6m +/-15 and a size of 2.6m which sounds about right



Doug

I didnt know anyone 'came' from Tuscon. I just thought people went for a conference and forgot to leave

Doug

That's how I read it - he said the long drive would be tomorrow (i.e. 27th ) - which is, well, today GMT


Doug

There's a new Director Update ( Jeff Favretto - he does cool ones )

He mentioned that Opportunity was instructed to drive 80 metres today and it is hoped it will do ONE HUNDRED AND SIXTY METERS tomorrow

let me say that again

ONE HUNDRED AND SIXTY METERS.

If they do it - it's a new mars distance record - and it'll put the heatshield as just a few pixels on Navcam and bring us to that first crater on the crater-hop image - which looks mainly like a bit of a Fram - but seing as it follows a new record and we're likely to set quite a few over the next few months - I think we should give them names of land speed record holders

So - Next stope - Green Crater ( followed by Noble, Gabelich, Breedlove, Arfons....)

Doug

It's barely possible kinematically ( i..e the IDD could reach perhaps 5% of the cells I'd guess ), and the 'brush' is, I believe, made of something like steel So it would scratch the hell out of the solar cell cover plates and possibly crack them

Reach back over your head with the inside of your elbow against your nose - the wrist just about on top of your head - and your hand probably just reaching over the back of your head. Now try and scratch your back No mobility left to do it

We see about as much as the IDD can do when it uses the MI, APXS and Mossbauer on the magnets on the front of the rover - and they used the MI on a few of the solar cells right near the front as well - but it just cant reach much further than that.

I spoke to Colin Pillinger on this very issue once - at an Open University Open Day - we were talking next to a Beagle 2 model - and a passer by said "couldnt you brush the solar panels clear of dust", and as Colin thought of a sensible way to answer, I simply replied "better to have dusty solar arrays than broken ones"

Doug

You kind of have to trust Pancam I guess. You calibrate it when you land - and then you can use housekeeping data and darkfields to calculate how it's performing thereafter

D

Just watched the bit-torrent

It's not a bad program, BUT, one big mistake

They're talking about how they wanted Spirit to drive out off the lander forwards - but it cant because of obstructive airbags - whilst showing....the back of the rover and the rear petal

Doug

Those little craters are just like Fram I'd imagine...

Vostok looks like it'll be a very interesting place though - almost like a stone age banjo enclosure

Oh - PS - where in hells name did you get that picture Is this another Pando situation? (From a happy-to-help insider, I could tell you, but I'd have to shoot you)

Wherever it came from thank you

PPS - for those confused, north is left on that image.

Doug