Water-cooled lander Options

[tanjent]

There is a recent posting on Emily's Planetary Society blog, which must be Doug's because she's not there herself, although her name is the only name on it. The subject is using water to cool a long-lived surface probe on Venus. It sounds far more practical than any of the other proposals for landing giant atomic-powered refrigerators, or developing a whole new family of high-temperature semiconductors, etc.

But I didn't understand the whispered criticism to the effect that the Ekonomov paper assumed that the water would absorb heat only from the one watt of power driving the instrument package itself. I simply can't believe that he went to the podium and presented his model without taking into account the fact that the surface of Venus is a pretty hot place, and that the proposed probe would be absorbing the ambient heat. This is an interesting proposal and I would like to understand both the original calculation of 50 days to bring the water to a boil, and the cited flaw in the calculation. I too find it hard to believe that it would take 50 days to bring water to a boil on the Venusian surface, but where exactly is the error, and what remains after we correct it?

Doug is busy of course, but I hope he will find the time to address this when he returns, if someone else hasn't done so by then.

[Greg Hullender]

For some reason, NASA issued a press release yesterday saying they've built an integrated circuit that runs at 600C.

http://www.nasa.gov/home/hqnews/2007/sep/H...licon_Chip.html

From the article, "This chip exceeded 1,700 hours of continuous operation at 500 degrees Celsius - a breakthrough that represents a 100-fold increase in what has previously been achieved. The new silicon carbide differential amplifier integrated circuit chip may provide benefits to anything requiring long-lasting electronic circuits in very hot environments."

Can't find a relevant paper about it yet though.

--Greg

[JRehling]

For some reason, NASA issued a press release yesterday saying they've built an integrated circuit that runs at 600C.

http://www.nasa.gov/home/hqnews/2007/sep/H...licon_Chip.html

From the article, "This chip exceeded 1,700 hours of continuous operation at 500 degrees Celsius - a breakthrough that represents a 100-fold increase in what has previously been achieved. The new silicon carbide differential amplifier integrated circuit chip may provide benefits to anything requiring long-lasting electronic circuits in very hot environments."

Can't find a relevant paper about it yet though.

--Greg

That's great news. I wonder how much of the workload that chip can handle, or if it's of toylike simplicity and is more of a proof of concept. And if it adheres to any other standards so that programming it doesn't require a boatload of software technology development.

I think this could go one of two routes: Either the new chip technology ends up producing a crude but servicable brain for Venus missions, which end up resembling 1970s computers, or they put still more effort in to interface the CPU and memory chips into prevailing standards, so that the programming work is similar to what it would be for using off the shelf technology on a typical space mission.

But this is a huge step. The steps that remain are something we know can be done.

Three Venus landers with camera and seismometers -- the Venusian Viking, after so many decades -- let's see it happen!