Got a desktop PC that's been sat on the floor for > a month? Go and look at it's PSU exhaust fan. FILTHY.

In a little-known footnote to space history, Voyager 1's Titan booster shut down prematurely after liftoff. The powerful Centaur upper stage was barely able to compensate, reaching escape velocity 3.4 seconds before running out of fuel. Luckily, Voyager 1 would still reach Jupiter and Saturn as planned.

However, had the underachieving Titan been used instead for Voyager 2, whose trajectory hinged on getting maximum performance from its booster, its eventual encounters with Uranus (in 1986) and Neptune (in 1989) would have been lost. By pure chance, Voyager 2 got the better rocket.

Out of interest, given the thin atmosphere and consequent small dust particle size limitation, just how much dust is there aloft?

The point of this is obviously not a practical one - rover planners have enough on their plates already without having to put together such an elaborate scheme, which could be made moot with rtg's anyway. I just found it a compelling image, with the rover seeming like a living organism trying to survive, perhaps the way a lizard finds a good spot to bask in the sun, but must balance basking with the need to forage for food.

There are 8 of them as I understand it - 6 on the battery, 2 on the REM. They each chuck out abotu 1W of heat. They've been doing so since the day they landed - and - except for decay - will carry on doing so for some time to come. Essentially they're there making a bad situation slightly less bad than it might be. they wont keep an entirely dead rover warm enough for survival - they just shave a bit off the heating requirements.

Continuing your analogy, why not use the heater to bring it up to 13 degrees C if that's all you need? Which is really my question, don't they have control over the heaters except for the emergency situation triggered by the low temperature? I would think using the heaters would be more efficient in heating the WEB than eg. running the processor.

I'm wondering why the turning on of the emergency heaters would be so bad? Is it so that they cannot be otherwise turned on, except automatically when the low temperature limit is reached? Is there a particular reason to run other electronics instead of the heaters, which I would think would be most efficient in warming the WEB?

... and a complementary question, do we know if any of previous orbiters (Mars xxx, Mariner 9, V1 & V2) already hit the planet or when they'll do so ?

According to the SpacEUROPE blog COROT's sensitivity may be just enough to detect reflected light from an extrasolar planet's surface in a similar manner Spitzer has done... but instead of infrared, it observes in the visible light.

I'm sure they ordered Oppy not to communicate this week-end so SS can read his own copy. or

I just think it would be a waste to completely throw away the advantages of solar power. The MER proves the application of the technology. I just want a brush so that we don't have to wait for the wind to blow.

Ah, I'm glad sombody knows this. I've only ever been able to find reference that all *loads* are removed from the battery. As clearly something of the solar array power gets to the BCB* (as it is this power that tells the BCB to reconnect the battery in the morning) I was never sure if the battery could be charged while in deep sleep.

Edited to add: Just noticed Doug's comment re the heater. Doh!, I'd forgotten that and it is quite likely that the temperature is high enough around the middle of the day to keep it off so that's a relief.
Also with reference to James Canvins comment regarding the wakeup current - I thought that wake up current was 2.0 amps which would keep it asleep until quite late in the day. I don't know what the panel output voltage range is but assuming it is only 10v then it would only just rise above 2A at the moment.

I don't know the specifics of the PCB, but is it intelligent enough to be preprogrammed for an expected wake up array voltage of X volts (when X is a lower number right now ) - which could be estimated to be 11am - then the master sequence for the day is sleep all day, wake up for the earliest Odyssey pass at which point you both uplink for the next day and downlink for that day, and then enter deep sleep till 19 hours later.