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Planetary News: Mars (2005)The Planetary Society's Mars Analog Blog:
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Credit: Troy Hudson |
Selecting and Stuffing
Yungay Station 3:00pm
This final full day at the station has seen an expected shift of focus away from science and towards more practical concerns of how we’re going to get all the equipment back out of the country. I’m feeling this most strongly, while others who are staying for another week and only concerned inasmuch as they’ve got to find equipment for me to carry back.
The amino acid extraction and detection lab that Peter, Andrew, and Allison have constructed reached full operating capacity only a few days ago. It’s a good thing, then, that they’re staying for another week to make use of this facility. But just as before we left we had to carefully think about what sorts of things we’d need in the field that we were unlikely to find in a hardware store in Antofagasta, they’ve now got to think about what they no longer need now that the lab is complete.
I’m carrying back the same amount that I left with: one large computer case, one tripod, and two large ‘action packer’ plastic tubs; the latter filled with as much equipment as possible and still remain under the weight limit. I’ve packed up the WP4 and KD2 instruments that were on loan from Decagon Devices. They have to be returned; else I’d still be running analysis on soil samples. Rather, I’m still taking soil samples for analysis back at JPL.
We don’t have something as nicely sophisticated yet simple as the WP4 for determining water potential, but I can use our ovens and precision balances to determine the total water content of the samples. Hopefully, I’ll find some correlation with the water potential and water content. But even if I don’t, that’ll be a useful result.
I’m going out to the field just outside the station where there’s a well-developed surface crust and about 5 to 10 cm of subsurface sand above the packed nitrate layer. I’m sampling both the crust and the subsurface every hour to get data on the diurnal variations of water content. Unfortunately, I started this endeavor at around 11am today, and since we have to leave the station at 8:30 am tomorrow, I’m not likely to get a complete series for this locality. I can probably fit together a series from other data I’ve taken this week, but it won’t be as rigorous. It’s always easy to look back and see how your experiments should have been done. But that means that if I ever come out here again, I’ll have a good idea of exactly what experiments I want to repeat and under what conditions. I only hope that the samples retain their water well during the trip back home.
I’d measure them here, but as mentioned before, we don’t have a balance precise enough to see the miniscule water content shifts before and after heating.
It’s back to packing up in a few minutes. One item that proved less than useful, unfortunately, and will be coming back with me is the vortex cooler. The cooler was behaving just fine, but requires more air pressure than the air compressor they were able to obtain can provide. We’d need several upright gas cylinders to keep it running throughout the whole week, and I think they had enough trouble getting one out here for the extraction machine. The compressor they had could only deliver a constant head of about 40 to 50 psi, which is only half of what the vortex cooler requires for proper operation. They were getting some cooling, but only down to about 10°C, whereas they needed it down to about zero. So, instead, they’ve reverted to the old standby of water and ice cubes. Good thing we have a working freezer.
Okay, now I need to see how much more stuff I can cram into these action packers.
Current Mood: packing (that really is a mood unto itself, isn’t it?)
Current Music: afternoon winds whipping through the station
[ what is this? ]