Loose Wire ? Options

[Marcel]

Looks to me a wire on the tip of Oppy's left array is not connected anymore

http://qt.exploratorium.edu/mars/opportuni...D9P2370L2M1.JPG

Or is it the angle of view that makes it look like that ?

[djellison]

When compared to

Sol 58 still attached
http://marsrovers.jpl.nasa.gov/gallery/all...30P2215L6M1.JPG


Sol 71 still there
http://marsrovers.jpl.nasa.gov/gallery/all...22P2281L2M1.JPG


Sol 122 still there
http://marsrovers.jpl.nasa.gov/gallery/all...09P2266L2M1.JPG

Then yup - strangely, after surviving launch, and multiple whacks on landing, looks like one of them has disconnected after a year of nothing. Probably the chill-bake dynamics finally got to it

Doug

[tedstryk]

It is either disconnected or hanging by a thread.

[dot.dk]

I think it is a result of lightning and pancam filter to give an illusion of a disconnected wire.

Here it looks alright
http://qt.exploratorium.edu/mars/opportuni...D9P2370R1M1.JPG

And if it got disconncted it is still wired on the other end

[akuo]

Looks still attached to me. The angle of light just makes the solar panel deck look a lot different between those images.

[tedstryk]

This begs the question of how long the rovers will last. Any guesses? My guess is despite this wire, it is to early to get an idea for Oppy. Could fail tomorrow, but its health seems quite robust. Spirit, on the other hand, I worry about, especially as we head into dust storm season. If it survives this, I think it will go until the Martian fall, when it will soon die from lack of power. I wonder if Oppy will last long enough to test the MRO relay. Seems like it could happen.

[djellison]

I was thinking that actually - dreaming of the data-budget you could return on hour-long MRO passes whilst it's still in an elliptical orbit during aerobraking

at 256kbps - it's just over 900 Mbits, and MRO MOI is in March '06 - so that would be something like Sol 750 - 760. Heck - perhaps they could test out the payload in the weeks preceeding MOI as a navigation tool.

Doug

[erwan]

I believe also that the disconnection it's an illusion, created mainly with shadows. I think he wire shadow (green) is prolongated by a dark detail belonging to the solar panel, similar to the other one seen a little below (red):

[tedstryk]

Wow, you could take a color panorama every few days....or take a few partial color pans of the same scene at different times of day.

[Marcel]

This begs the question of how long the rovers will last. Any guesses? My guess is despite this wire, it is to early to get an idea for Oppy. Could fail tomorrow, but its health seems quite robust. Spirit, on the other hand, I worry about, especially as we head into dust storm season. If it survives this, I think it will go until the Martian fall, when it will soon die from lack of power. I wonder if Oppy will last long enough to test the MRO relay. Seems like it could happen.

It depends on what you define as "last". Ploughing around, climbing, trenching, RATting and shaking rocks out of it's wheel will be over when the energy budget is too low and some day this will not be in Spirit's capabilities anymore due to accumulated dust. But keeping in touch, sending data once in a while and maintain stable (thermal stability, operating transmitter/receiver and antenna-mobility) needs muuuuuch less energy.

Can someone tell me roughly how much energy an exhausted and dusty MER needs in order to stay in touch ? I realise it is not easy to find out about this number. Ultimately though, this number could be extrapolated to the degradation characteristics of the solar array current, which (combined with the seasonal changes) could lead to a rough estimation of the end of the mission (which i consider the moment the last bit is received).
One aspect is harder to predict with respect to the above but certainly needs extra attention: a long term global dust storm. Could it kill a MER off right away ? In other words: could it diminish the amount of energy converted in the arrays so much for such a long time, that all that's left afterwards is a cold rover without any juice in it's batteries left ? And then what ? Is it programmed in such a way that it wil start transmitting when the sun starts shining again ? Or is it battery = empty = the end ?

[djellison]

This begs the question of how long the rovers will last.  Any guesses?  My guess is despite this wire, it is to early to get an idea for Oppy.  Could fail tomorrow, but its health seems quite robust.  Spirit, on the other hand, I worry about, especially as we head into dust storm season.  If it survives this, I think it will go until the Martian fall, when it will soon die from lack of power.  I wonder if Oppy will last long enough to test the MRO relay.  Seems like it could happen.

It depends on what you define as "last". Ploughing around, climbing, trenching, RATting and shaking rocks out of it's wheel will be over when the energy budget is too low and some day this will not be in Spirit's capabilities anymore due to accumulated dust. But keeping in touch, sending data once in a while and maintain stable (thermal stability, operating transmitter/receiver and antenna-mobility) needs muuuuuch less energy.

Can someone tell me roughly how much energy an exhausted and dusty MER needs in order to stay in touch ? I realise it is not easy to find out about this number. Ultimately though, this number could be extrapolated to the degradation characteristics of the solar array current, which (combined with the seasonal changes) could lead to a rough estimation of the end of the mission (which i consider the moment the last bit is received).
One aspect is harder to predict with respect to the above but certainly needs extra attention: a long term global dust storm. Could it kill a MER off right away ? In other words: could it diminish the amount of energy converted in the arrays so much for such a long time, that all that's left afterwards is a cold rover without any juice in it's batteries left ? And then what ? Is it programmed in such a way that it wil start transmitting when the sun starts shining again ? Or is it battery = empty = the end ?

150 WHrs per sol for basic housekeeping and nothing else.

250 Whrs per sol would allow for daily operations of some nature I'd imagine.

350 Whrs per sol allows for a tiny bit of science obs

Spirits on 400ish I think, and Oppy is way up there somewhere on 600ish

Doug

[MahFL]

I am sure I remember at one of the press conferences when Spirit had the memory problem it was said that if the rover has flat batteries it can operate on solar power alone, this is of course if the warm electronics box is not damaged due to the cold, which of course it can be.