[X] My Assistant

[maycm]

From the following "Space" article LINK

Spirit’s solar arrays currently produce about 650 watt hours while Opportunity’s generate up to 700 watt hours, Laubach said. A minimum of 300 watt hours is required for Spirit to function, though Opportunity can operate on slightly less, she added.

What is the reason for the lower power requirements of Oppy?

I thought the two rovers were identical.

[helvick]

I've overhauled my solar power estimate charts with the most recent power generation information. I've also properly reworked the calculated data in these charts to include an accurate model of the available insolation for each rover and also included an estimated value that factors in the effects of Tau using the values published in the MER Analyst Notebook.


Spirit Key Dates:
If the current dust deposition rate holds (~0.08% power loss per sol) Spirit's normal power generating capability will drop below 300whr per sol on Sol 865 (June 9th) and stay below that until Sol 997 (October 22). Those power levels effectively eliminate any significant mobility unless she has a very favourable location.
The worst period is from sol 919 to Sol 943 when power will be no more than 275whr per Sol unless she is oriented towards the Sun.


My reworked figures actually put Opportunity in a much more favourable power situation. Aggregate dust loss over the past 100 Sols has been very close to 0.04% per Sol. That means that Opportunity should be able to generate more than 457whr throughout the winter period and while that is a restricted power budget it is more than Spirit currently has available.

[jamescanvin]

Spirit Key Dates:
If the current dust deposition rate holds (~0.08% power loss per sol) Spirit's normal power generating capability will drop below 300whr per sol on Sol 865 (June 9th) and stay below that until Sol 997 (October 22). Those power levels effectively eliminate any significant mobility unless she has a very favourable location.
The worst period is from sol 919 to Sol 943 when power will be no more than 275whr per Sol unless she is oriented towards the Sun.

OK, so two questions arising from this.

1) Can anybody estimate the angle of north slopes of McCool hill?

and given that. (for helvick)

2) What kind of power figures can we expect while wintering there?

James