Hopefully some dark skies here...... my new shiny DSLR needs a work out

Doug

- I've gotta find me a new bank

Doug

That was the plan SL - if it wandered too far from the subject, it was a swathe of OT post deletions and not a deletion of the entire thread that I had in mind.

One thread of Pure Science/Sheer Drama is probaby enough though

Doug

This all makes great reading It's odd - in 'the moment' of these things, you don't really take in the content, you just try not to miss something out.

Doug

A thread on the subject on the Red Rain was deleted a few months ago because it was fundamentally off topic for UMSF. I wont delete this thread as it's about the program - but if it moves that way....I will.

Doug

Thanks for the heads up Emily - nice write up....I had forgotten about the old Nav camera...we never saw much from that (well, one image) - I hope they dump it's entire results onto the PDS...might make a nice movie

Doug

Well - roughly speaking, am I right in thinking that if you take the range in km, take a zero off, you can call it about that many cm/pixel ( i.e. 250-300k orbit = 25-20cm/pixel )

So - a good Phobos targetting opportunity would be about 10m/pixel, and Deimos about 25m/pixel

Doug

MRO has been been commanded...

2006-319T18:20:35 ri3500 r01st_mgs_image_319.abs

Sent about 6 hrs ago. Can't tell which instrument it is ( although CTX as 'pin down' and HiRISE as a follow up would make the most sense )

Meanwhile, many repeated commands to MGS - Tuesady and most of Wednesday seemed packed full of more explicit transmitter commands - turning on heaters etc etc - but repeated many times - cycling between 'sides' so one presumes still an 'in the dark' set of commands...just trying all options.


Doug

All the camears in question are push broom cameras - they require the motion of the planet below them to build up the 'length' of an image.

You can get creative with their operation when it comes to tracking down MGS though

Doug

Yup - what you describe is the process of remaining power positive.

The moment you have less power than you require for basic survival....then you are running a very dangerous game. I imagine a Mars orbiter would get very cold very quickly without power whilst in eclipse - Once you have a spacecraft that has basically 'browned out' - you have no means to maintain attitude, and nasty things can start to happen such as frozen prop etc.

The only story I know of a recovery from that sort of problem was with SOHO - and that was a very very lenghty procedure that began with something as crazy as bouncing radar signals off the spacecraft with the Areciebo dish to identify its orientation and spin rate.

In some respects - imaging MGS with an one or more MRO instruments is a martian equiv of that - identify the physical config of the spacecraft - or even better - do it twice to identify what, if any, attitude control it is exhibiting.

Doug

If one is truely worried about contaminating Enc or Titan - then I think a Galileo end has to be the only option. It must surely be possible to put the thing onto a trajectory that...even if pertubed by ring collisions...would still make it to top of the atmosphere.

Doug

When I started this place a couple of years back - I never thought I'd see a debate between MOC/CTX and HiRISE people over the relative difficulty of photographing spacecraft - what a very very sureal thing to read over ones cornflakes

Doug

"We'll use HiRISE on Friday"
"We'll use CTX on Wednesday then HiRISE on Friday"
"We'll use a long exposure with HiRISE on Wednesday then a targetted observation on Friday"

The usual suspect media outlets have all reported one or more of those.....so it's been a bit confusing for the layperson.

Doug

Yeah - in the past with pancam mosaics I've been trying to show - I've ended up showing a smaller version that I pan across - and then select sample pieces at full res......but I'm basically re-producing my range of talk presentations and was hoping I could come up with something a bit better.

I've found some answers over at Msoft's site....but they're mainly the same ones we had here...slice'n'dice'n'animate, and there's a VBA script that can move large images - BUT - with no control on speed etc.

It's a right royal pain in the ass.....damn MER and MRO with their large image products...

Doug

Oh - I can do the whole after-effects-scroll-an-image thing to make a WMV or whatever....BUT.....imagine a PPT with 20 such things......it's half a gig in size before you've even started - and I've never been 100% happy that powerpoint, movies, and projectors run from laptops are a 'safe' combo in a 'live' environment.

It seems as if the capacity to do what I want is within the limits of Powerpoint, if they'd just let it.

Doug

"Spitzer, which trails Earth in its orbit, now needs the 70-meter dishes."

I did NOT know that - wow....that's a serious stretch on resources - I'd forgotten about that write up - it reads pretty much the same as the one I saw at IAC really.

Doug

Well - this works...

it sucks ( you can see seams )

But it sort of works

But SURELY.....I should be able to do this the easy way in one go?

I'm looking forward to Keynote 3 being unveiled early next year - this single issue, if solved with that, would actually push me onto the Mac platoform...

Doug

Or maybe it's just time the DSN got the investment it deserves to install multiple 70m assets at each station, or the arrays of mass produced 12m dishes suggested at IAC.
http://www.iac-paper.org/abstractcd/2006/a...-06-B3.1.03.pdf



Doug

No - we'd have to use the DSN to command MGS to turn on it's UHF transmitter during a rover flyover...and then the rovers would report back to see if it worked....I MAY be wrong but I don't believe that MGS can be commanded via UHF.

Also - Stanford might get out their UHF antenna and see if a UHF carrier from MGS can be seen here on the ground....sometimes it gets a signal from Mars Orbiters, sometimes it doesn't.

Doug

The thinking behind it is probably like this :

We are sending X-Band signals, but we do not know if it is getting them as we see no evidence in return

Most likely option - the vehicle is incapacitated and/or not recieving the signals.
Less likely - the vehicle is recieving them but for some reason can not transmit on X-Band

In the second case - if we uplink a command to transmit on UHF which Spirit/Opportunity might hear, then we will have evidence of life onboard MGS.

Basically, you start at the top of the fault tree and cross out all the different failure options until you've crossed them all out....at which point you go out, have a drink, toast MGS, and then move on.

Anyone who followed the MPL post-landing story will have been through this...it's painful, as you get to the increasingly unlikely failure modes, but on which you end up pinning more and more of your hopes.

Doug

Calm down boys....calm down.


Anyway - back to the actual topic in hand...

Odyssey or MRO to MGS UHF comms - I've not thought of that but it should be possible - however I imagine that the signal strength pattern from the UHF antenna would require a serious spacecraft manouver for it to work.

Doug

It should scroll UP.

Doug

That's an interesting point - if I make, say, 5 1024x768 images and just line them up next to one another - will that work...I'll try it

Doug

Clearly we have some utter MS Office gurus in this place.....SO....here's one for you...

http://www.unmannedspaceflight.com/doug_im...age_problem.ppt


Simple powerpoint file - a large JPG imported, and I want to scroll the JPG up (or more often in a MER case.....along) for added OOoooo factor. You can see the custom animation I've added, a simple motion path upward.....but there's a problem

Try playing the presentation

click - image fades on......lovely.

click - image begins to scroll along.....lovely - but watch what happens at about the point where what was at the bottom of the screen reaches the top.....BAM...the image stops showing - it'll keep scrolling for the duration of the custom anim - but it gives up trying to show the image.

I've got a fairly powerfull laptop here, 2 gig of ram in it...SURELY I should be able to scroll an image like that without Powerpoint just throwing its hands in the air and giving up?

Any pointers to solve THAT one..

What I often have to end up doing is just showing little bits of large images, and that...well....SUCKS I mean really, I should be able to scroll say a 4000 x 768 pixel image shouldn't I ?

:0

Doug

One could have made the same statement about Spirit once it reached the Summit of husband hill.....

No - to tell the pictorial story of the MER mission - you have to tell the FULL story - from start, to FINISH.

It's hard enough to get a single book published, let alone a book + a second edition.

Doug