[X] My Assistant

[Astro0]

Well, with perhaps a few more weeks of tilt-enhancing drives to go and then settling in for the winter, I thought it might be a good time to have a thread dedicated to ideas and observations that will come. It's likely that we won't hear much from Spirit during the coldest part of winter (April-June) possibly longer. There'll hopefully be beeps to tell us that she's still alive.

Already there are plans for radio science and determining the fluidity or otherwise of the Martian core, plus weather observations, surface changes etc.
What else could you think of that Spirit could do? Remember that she's not going anywhere (vonBraun is out)

In the meantime, have you sent your postcard to Spirit yet?! It's a great idea from the Mars outreach team.
http://beamartian.jpl.nasa.gov/spiritpostcards
What would you say to Spirit?

[Poolio]

Thinking about the "hibernation" period for Spirit some more, I have a couple questions. Forgive me if these have been covered before; I don't recall seeing anything...

Once she has "shut down" and is hibernating, is it correct to assume that Spirit will not be consuming any power? If so, wouldn't that mean that what little power the panels do generate each day (whether its 10 whr or 100) would go into charging the batteries? And if that's the case, could we expect Spirit to wake up periodically throughout the winter and try to make contact? (Even though the simple act of waking up may prompt her to trip a low-power fault again.)

During any brief periods of wakefulness, would the computers generate enough heat to provide some warmth to the WEB? And (finally!) would such temperature cycles be helpful or harmful to her chances of long term survival?

Sorry for all the hypotheticals. I know that the hibernation period has been discussed, but I don't recall seeing anything about the possible effects of cyclic sleeping and waking.

[djellison]

is it correct to assume that Spirit will not be consuming any power? .......would the computers generate enough heat to provide some warmth to the WEB? And (finally!) would such temperature cycles be helpful or harmful to her chances of long term survival?

Back in the pre-Victoria entry power crisis, but that was nearly 3 years ago, so I'm working off unreliable memories here...

These documents may help :
http://trs-new.jpl.nasa.gov/dspace/handle/2014/13037
http://trs-new.jpl.nasa.gov/dspace/handle/2014/13105
http://trs-new.jpl.nasa.gov/dspace/handle/2014/37750
http://trs-new.jpl.nasa.gov/dspace/handle/2014/17736

in particular

The response to low batteries or power faults does not use the scheduled communication windows. If the rover is awake when a low battery situation occurs, the flight software has 60 seconds to quickly shut down before the BCB removes the batteries from the power bus. If it is nighttime when the BCB detects a low battery condition, the BCB takes the battery offline and the power bus crashes. Eventually, when the sun rises, the solar array power supports the bus and the BCB. As the batteries charge back up, the BCB puts them back online to support the bus. At the next solar wakeup, the flight software schedules one LGA communication window at a predetermined hour (11:00 LST) to report to Earth. No UHF windows are attempted because these usually occur in the early morning or late afternoon, when the available solar power is low. The vehicle remains in this configuration (with autonomous shutdown mode active, in receive mode via the LGA, performing one DTE window per day) until the operations team reconfigures the vehicle to resume normal operations

As I understand it, the Rover Battery Control Board ( RBCB / BCB ) remains on - managing and measuring the power generated by the arrays and the battery, and issuing wakeup to the main computer based on either a specific power being generated or a timer.

How, exactly, this will tie in to brown outs, low power faults etc, I don't know

Also - there are RHU's within the WEB to generate a certain ammount of heat.

As for thermal cycles, every single day-night cycle is a thermal cycle and every single one runs the risk of a solder fracturing or a wire breaking.