Hackaday Links: September 11, 2022

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Good news out of Mars from the little lunchbox that could — in the seven times that MOXIE has run since it arrived in February 2021, it has reached its target production of six grams of oxygen per hour, which is in line with the output of a modest tree here on Earth. The research team which includes MOXIE engineers report that although the solid oxide electrolysis machine has shown it can produce oxygen at almost any time or day of the Martian scale, they have not shown what MOXIE can do at dawn or dusk, when the temperature changes are substantial, but they say they have ‘an ace up (their) sleeve’ that will let them do that. We can’t wait to see what they mean.

In other, somewhat funnier space news — early last Sunday morning, the ESA’s Solar Orbiter was cruising by Venus as part of a gravity-assist maneuver to get the Orbiter closer to the Sun. Two days before the Orbiter was to reach its closest point to the spacious star, it spat a coronal mass ejection in the general direction of both Venus and the Orbiter (dibs on that band name), as if to say ‘boo’. Fortunately, the spacecraft is designed to withstand such slights, but the same cannot be said for Venus — these events have their way with Venus’ atmosphere, depleting it of gasses.

Is this not the most Hackaday-esque thing you’ve ever heard of? A solar-powered, Arduino-driven cockroach. Not a robot, an actual cockroach with a backpack. Why? Cyborg insects for urban search and rescue missions, obviously. We’d make some quip like ‘all it needs is a Nixie tube’, but in all seriousness, that would just weigh them down needlessly.

So anyway, here’s (an ‘Arduino guitar device’ playing) Wonderwall.

10 thoughts on “Hackaday Links: September 11, 2022

  1. > they have not shown what MOXIE can do at dawn or dusk, when the temperature changes are substantial

    MOXIE is designed to operate for approximately one day out of every 2 months (1 hours at a time), so it may take a while before enough data is collected for a meaningful analysis of what happens at dawn and dusk throughout the Martian year ( 687 Earth days ).

  2. So, running full-tilt, MOXIE produces about a sixth of the oxygen required to keep a resting human alive. The 2 kilowatt radioisotope heat source that powers it can only supply a third of the power it needs, and must charge batteries for at least 3+ hours to get an hour of runtime. In reality, it’s much more than that because of all the other electrical loads it must service too.

    Based on that, it looks like you need 6+ kilowatts of radioisotope thermal power, or about 15 kg of plutonium oxide, just to provide enough oxygen to keep just one person alive. That’s roughly the whole world’s inventory right now.

    I’m sure moving to a real fission reactor will reduce the thermal power and fuel needs but still, that’s a lot of power just for oxygen.

    Solar? OK, looks like 150-200 square meters or so on Mars. And much more if you want light, heat, or food too.

    1. For stationary installation on Mars, small-scale fission reactors are probably the only power source that makes sense in the next few decades. Solar power will work only if the panels can be produced on Mars.

    2. “production of six grams of oxygen per hour, which is in line with the output of a modest tree here on Earth”. They must be very modest trees. A typical Douglas fir is more like 30+ grams per hour

  3. The oxygen we breathe doesn’t come from trees and forest. Almost all oxygen produced in a forest in retaken by the forest itself during the life (and death) cycle of the trees and fires. The rest is fossilized and liberated after several 100k years by soil erosion. So the trees’ oxygen we breathe today comes from old fossilized forest. Which is a marginal contribution compared to the oxygen we get from the sea’s phytoplanktons. That’s why ocean acidification is much more of a concern compared to Amazon rainforest destruction.

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