[X] My Assistant

[Nirgal]

some time ago, helvick posted the following excellent analysis of the
MER solar power situation as an extrapolation of a diagram showing Watts/hours
against Sols.

http://www.unmannedspaceflight.com/index.p...ype=post&id=580
(originally posted in: http://www.unmannedspaceflight.com/index.p...722&#entry10722)

What makes this chart (let's call it Helvick's Power Chart, HPC so useful, is it's taking into account all relevant factors contributing to the remaining power life time of the rovers: seasonal solar input, gradual attenuation by dust accumulation, and (last not least the "pushing" of the cleaning events.

So here is my suggestion to use this thread/topic for updating this chart
whenever new power figures (watts/hours) and/or new cleaning events are
reported by JPL.

This would be a great way to always get an overview of the best guess of the maximum remaining rover life time (i.e. the limit imposed by the solar power...
which, of course does not take into account failure for other reasons, but would be a nice estimate of the maximum expected lifetime of our little heros

The latest JPL power report

The rover's power team reported a dust-cleaning event on Opportunity between sols 524 and 526. Daily power output from solar panels increased from about 500 watt hours to about 650 watt hours.

underlines the remarkable accuracy of the HPC:
helvick posted the chart on May 18 (aronud Sol 460) predicting the 500 Watts/hour for around Oppy-Sol 540 (note, that the chart shows Spirit-Sols),
which is very well in agreement with the new JPL report !

Now, with 650 Watts at Sol 530 after the cleaning event, the "critical-below-300-Watt-drop" would be deferred from (approx) Sol 680 to Sol 750, in other words:
about 70 extra Sols as a gift from the cleaning event ;-)

[djellison]

I think it'll be like gambling. Sometimes you win, sometimes you loose,but eventually, the house will always win and the output drops below a critical level.


Doug

[dvandorn]

I think it'll be like gambling. Sometimes you win, sometimes you loose,but eventually, the house will always win and the output drops below a critical level.
Doug

I'm reminded of the lyric to the song "The Gambler" -- I should write up a whole lyric, but the line that springs to mind is:

"And somewhere in the darkness,
Ol' Spirit, she broke even..."

-the other Doug

[mars loon]

Well this power chart is outstanding, exactly what's needed for presentations.

may I suggest adding a few real time earth dates (month/yr), perhaps every 100 to 150 Sols, at bottom.

Also, Martian seasons on top to correlate with estimated max power


thanks.

[helvick]

Another variation..

Added a table for Martian Seasons in Mission Year 1\2 (Solstice\Equinox) and Landing anniversary date.
Changed X-Axis to reflect Earth Date (M\D\YY) & Spirit sol
Added shading to indicate the current date (split between "known" data and extrapolated data)

I'm still looking for more precise data on the actual power and want to work on building a better model for the "Estimated Max Power" data - I got the data for this by lifting some values from an insolation chart I found online and making some outrageous assumptions but really want to recalculate that based on actual orbital data\lattitude.

The pointing data that Michael Howard has put together for MMB makes me think that I should be able to get sufficiently accurate information on the actual orientation\inclination of the Rovers to work out pretty accurate "maximum theoretical power"

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